DTC P1604: STARTABILITY Malfunction: Notes

DTC detecting condition: 

Immediately at fault recognition

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON(DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .
   NOTE: For detailed operation procedures, refer to the "Subaru Select Monitor". Ref. to COMMON(DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC other than P1604 displayed? (Current malfunction)

   Yes

   Check DTC using "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC TROUBLE CODE (DTC) .

   No

   Go to  2 .

Check the immobilizer. Ref. to IMMOBILIZER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

Is the check result OK?

Yes

Go to  3 .

No

Repair the immobilizer. Ref. to IMMOBILIZER (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

Check for the condition of fault occurrence.

Is it possible to reproduce the faulty phenomenon or to identify the faulty condition?

Yes

Go to  30 .

No

Go to  4 .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, read the values in [Engine Speed] and [Control module voltage].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref to. COMMON(DIAG)>FREEZE FRAME DATA .

   Is the value of [Engine Speed] 0 RPM?

   Yes

   • When the value of [Control module voltage] is less than 5 V: Check the battery.

     Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY>INSPECTION .

   • When the value of [Control module voltage] is 5 V or more: Go to  5 .

   No

   • When the value of [Engine Speed] is less than 250 RPM: Go to  12 .
   • When the value of [Engine Speed] is 250 RPM or more: Go to  20 .

Using the Subaru Select Monitor, read the value in [Control module voltage].

Is the value of [Control module voltage] less than 9 V?

Yes

It is possible that the engine friction is too large. Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

No

• When the value of [Control module voltage] changes in any one of freeze frame data: Go to  6 .
• When the value of [Control module voltage] does not change in all freeze frame data: Check the starter motor circuit. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>STARTER MOTOR CIRCUIT .

Check the installation condition of crankshaft position sensor.

Is the crankshaft position sensor installed correctly?

Yes

Go to  7 .

No

Install the crankshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

Check the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR>INSPECTION .

Is the check result OK?

Yes

Go to  8 .

No

Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the crankshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between crankshaft position sensor connector and engine ground.

   Connector & terminal 

   (E10) No. 3 (+) - Engine ground (-):

   Is the voltage 4.5 V or more?

   Yes

   Go to  9 .

   No

   Repair the power supply circuit.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

   Connector & terminal 

   (E158) No. 66 - (E10) No. 1:

   (E158) No. 68 - (E10) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  10 .

   No

   Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

Measure the resistance between crankshaft position sensor connector and engine ground.

Connector & terminal 

(E10) No. 1 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  11 .

No

Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

1. Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, read the values in [Engine Coolant Temperature 1], [Ambient air temperature] and [Fuel Pump Duty].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>FREEZE FRAME DATA .

   Is the value of [Engine Coolant Temperature 1] 120°C (248°F) or more? Or is the value of [Engine Coolant Temperature 1] 15°C (27°F) or more lower than that of [Ambient air temperature]?

   Yes

   Replace the engine coolant temperature sensor (outlet). Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .

   No

   • When the value of [Fuel Pump Duty] is 60% or more: Go to  13 .
   • When the value of [Fuel Pump Duty] is less than 60%: Check the fuel pump system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

1. Using the Subaru Select Monitor, select [Fuel Pump Relay] of [Active Test].
   NOTE: For detailed procedures, refer to "Active Test". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>ACTIVE TEST .
2. Check if operating sound occurs in the fuel pump according to ON/OFF switching operation. Does the fuel pump emit operating sound?

   Yes

   Go to  15 .

   No

   Go to  14 .

Check fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes

Check fuel pump system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

No

Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

Check if any foreign matters such as iron powder exist in the fuel tank.

Is there any foreign matter in the fuel tank?

Yes

Remove foreign matter from the fuel tank.

No

Go to  16 .

Measure the fuel pressure. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 350 - 450 kPa (3.5 - 4.6 kg/cm² , 50 - 66 psi)?

Yes

Go to  17 .

No

Check the fuel pump and fuel delivery line. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL DELIVERY AND EVAPORATION LINES>INSPECTION .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, read the values in [Fuel Rail Pressure A] and [Commanded Fuel Rail Pressure A].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>FREEZE FRAME DATA .

   Is the value in [Fuel Rail Pressure A] synchronized with the one in [Commanded Fuel Rail Pressure A] in all freeze frame data?

   Yes

   Go to  18 .

   No

   Check the high-pressure fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>HIGH PRESSURE FUEL PUMP>INSPECTION .

1. Turn the ignition switch to OFF.
2. Disconnect the connectors from ECM and fuel injectors.
3. Measure the resistance of harness between ECM connector and fuel injector connector.

   Connector & terminal 

   #1 (E158) No. 96 - (E5) No. 1:

   #1 (E158) No. 87 - (E5) No. 2:

   #2 (E158) No. 95 - (E16) No. 1:

   #2 (E158) No. 86 - (E16) No. 2:

   #3 (E158) No. 93 - (E6) No. 1:

   #3 (E158) No. 84 - (E6) No. 2:

   #4 (E158) No. 94 - (E17) No. 1:

   #4 (E158) No. 85 - (E17) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  19 .

   No

   Repair the open circuit of the harness between the ECM connector and fuel injector connector.

Measure the resistance between the ECM connector and engine ground.

Connector & terminal 

#1 (E158) No. 96 - Engine ground:

#1 (E158) No. 87 - Engine ground:

#2 (E158) No. 95 - Engine ground:

#2 (E158) No. 86 - Engine ground:

#3 (E158) No. 93 - Engine ground:

#3 (E158) No. 84 - Engine ground:

#4 (E158) No. 94 - Engine ground:

#4 (E158) No. 85 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  29 .

No

Repair the short circuit to ground in harness between ECM connector and fuel injector connector.

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, read the values in [Engine Coolant Temperature 1], [Ambient air temperature] and [Engine Speed].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>FREEZE FRAME DATA .

   Is the value of [Engine Coolant Temperature 1] 120°C (248°F) or more? Or is the value of [Engine Coolant Temperature 1] 15°C (27°F) or more lower than that of [Ambient air temperature]?

   Yes

   Replace the engine coolant temperature sensor (outlet). Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .

   No

   • When the minimum value of [Engine Speed] is less than 300 RPM: Go to  21 .
   • When the minimum value of [Engine Speed] is 300 RPM or more: It is possible that the engine compression pressure is not sufficient. Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

Check fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR>INSPECTION .

Is there any deposit in the fuel injectors?

Yes

Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

No

Go to  22 .

Check if any foreign matters such as iron powder exist in the fuel tank.

Is there any foreign matter in the fuel tank?

Yes

Remove foreign matter from the fuel tank.

No

Go to  23 .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, read the value in [Engine Coolant Temperature 1].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>FREEZE FRAME DATA .

   Is the value of [Engine Coolant Temperature 1] 40 - 90°C (104 - 194°F)?

   Yes

   Go to  25 .

   No

   Go to  24 .

Measure the fuel pressure five minutes after the engine is stopped. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 147 kPa (1.5 kg/cm² . 21 psi) or more?

Yes

Go to  29 .

No

Replace the pressure regulator. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL FILTER .

1. After the engine is stopped. scavenge inside of the intake manifold by applying compressed air.
2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.
   NOTE: Remove the vacuum hose between intake manifold and purge solenoid valve and perform the measurement. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>GENERAL DESCRIPTION>COMPONENT>FUEL PIPE .

   Is the HC concentration less than 4000 ppm?

   Yes

   Go to  27 .

   No

   Go to  26 .

Check fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR>INSPECTION .

Is the check result OK?

Yes

Go to  27 .

No

Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

Check throttle body. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>THROTTLE BODY>INSPECTION .

Is there any deposit in the throttle body?

Yes

Replace the throttle body. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>THROTTLE BODY .

No

Go to  28 .

Check the installing condition of the air intake system.

Are there holes. loose bolts or disconnection of hose on air intake system?

Yes

Repair the air intake system. Ref. to INTAKE (INDUCTION) (H4DO)>GENERAL DESCRIPTION .

No

Go to  29 .

Check for the condition of fault occurrence.

Is the fault removed?

Yes

Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

No

Go to  30 .

Check for the condition of fault occurrence.

Does cranking occur?

Yes

• When the engine speed is abnormal during cranking: Go to  37 .
• When an initial combustion does not occur: Go to  40 .
• When the engine stalls immediately after engine start: Go to  57 .
• When the engine takes time to start: Go to  79 .

No

Go to  31 .

Check for the condition of fault occurrence.

Does the sound occur by a protruding starter pinion gear during cranking?

Yes

• When the starter motor does not rotate: Go to  32 .
• When the starter motor rotates but does not engage: Go to  34 .

No

Go to  35 .

Check the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY>INSPECTION .

Is the check result OK?

Yes

Go to  33 .

No

Charge or replace the battery. Ref. to STARTING/CHARGING SYSTEM (H4DO)>BATTERY .

Using the ST. rotate the crankshaft.

ST 18252AA000 CRANKSHAFT SOCKET 

Does the crankshaft rotate smoothly?

Yes

Check the starter motor. Ref. to STARTING/CHARGING SYSTEM (H4DO)>STARTER>INSPECTION .

No

It is possible that the engine friction is too large. Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

Check the starter motor. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER>INSPECTION .

Is there any wear or damage in the starter pinion gear?

Yes

Repair the starter motor. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER .

No

Replace the torque converter assembly. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>TORQUE CONVERTER .

Check the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY>INSPECTION .

Is the check result OK?

Yes

Go to  36 .

No

Charge or replace the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY .

Check the starter motor. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER>INSPECTION .

Is the check result OK?

Yes

Check the starter motor circuit. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>STARTER MOTOR CIRCUIT .

No

Repair the starter motor. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor. read the value of [Engine Speed] during cranking.
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>DATA MONITOR .

   Is the value of [Engine Speed] 300 RPM or more?

   Yes

   It is possible that the compression pressure of the engine is not sufficient. Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

   No

   Go to  38 .

Check the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY>INSPECTION .

Is the check result OK?

Yes

Go to  39 .

No

Charge or replace the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY .

Using the ST. rotate the crankshaft.

ST 18252AA000 CRANKSHAFT SOCKET 

Does the crankshaft rotate smoothly?

Yes

Check the starter motor. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>STARTER>INSPECTION .

No

It is possible that the engine friction is too large. Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

Using a sound scope. check each fuel injector for operation sound during cranking.

Does the fuel injector emit operating sound?

Yes

Go to  41 .

No

Go to  54 .

Measure the fuel pressure. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 350 - 450 kPa (3.5 - 4.6 kg/cm² . 50 - 66 psi)?

Yes

Go to  42 .

No

Go to  52 .

Check the ignition condition. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes

Go to  43 .

No

Go to  46 .

Check for the condition of fault occurrence.

Does the fault occur only within approx. 15 to 120 minutes after the engine is stopped?

Yes

Go to  45 .

No

• When the fault occurs in two or three minutes or a long time after the engine is stopped: Go to  44 .
• When the fault occurrence pattern is inconsistent: Go to  93 .

Measure the fuel pressure five minutes after the engine is stopped. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 147 kPa (1.5 kg/cm² . 21 psi) or more?

Yes

Go to  93 .

No

Replace the pressure regulator. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL FILTER .

1. After the engine is stopped. scavenge inside of the intake manifold by applying compressed air.
2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.
   NOTE: Remove the vacuum hose between intake manifold and purge solenoid valve and perform the measurement. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>GENERAL DESCRIPTION>COMPONENT>FUEL PIPE .)

   Is the HC concentration less than 4000 ppm?

   Yes

   Go to  93 .

   No

   Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

Check the spark plug. Ref. to IGNITION (H4DO)>SPARK PLUG>INSPECTION .

Is the check result OK?

Yes

Go to  47 .

No

Replace all spark plugs on all cylinders. Ref. to IGNITION (H4DO)>SPARK PLUG .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor. record the value of [Engine Speed] during cranking,
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>DATA MONITOR .

   Does the recorded value of [Engine Speed] contain data of 0 RPM?

   Yes

   It is possible that temporary fault occurs in the crankshaft position sensor circuit. Check the crankshaft position sensor circuit. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0335 CRANKSHAFT POSITION SENSOR "A" CIRCUIT .

   No

   Go to  48 .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ignition coil.
3. Turn the ignition switch to ON.
4. Measure the voltage between ignition coil connector and engine ground.

   Connector & terminal 

   (E31) No. 1 (+) - Engine ground (-):

   (E32) No. 1 (+) - Engine ground (-):

   (E33) No. 1 (+) - Engine ground (-):

   (E34) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  49 .

   No

   Repair the following item.

   • Open or short to ground in power supply circuit
   • Poor contact of coupling connector
   • Blown out of fuse

1. Disconnect the connector from ECM.
2. Measure the resistance of harness between ECM connector and ignition coil connector.

   Connector & terminal 

   (E158) No. 10 - (E31) No. 2:

   (E158) No. 11 - (E32) No. 2:

   (E158) No. 12 - (E33) No. 2:

   (E158) No. 13 - (E34) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  50 .

   No

   Repair the open circuit in harness between ECM connector and ignition coil connector.

Measure the resistance of harness between ECM connector and engine ground.

Connector & terminal 

(E158) No. 10 - Engine ground:

(E158) No. 11 - Engine ground:

(E158) No. 12 - Engine ground:

(E158) No. 13 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  51 .

No

Repair the ground short circuit of harness between ECM connector and ignition coil connector.

1. Turn the ignition switch to OFF.
2. Measure the resistance of harness between ignition coil connector and engine ground.
   NOTE: Connect all connectors after measurement.

   Connector & terminal 

   (E31) No. 3 - Engine ground:

   (E32) No. 3 - Engine ground:

   (E33) No. 3 - Engine ground:

   (E34) No. 3 - Engine ground:

   Is the resistance less than 5 Ω?

   Yes

   Replace the ignition coil. Ref. to IGNITION (H4DO)>IGNITION COIL . If the fault occurs after servicing, continue the diagnosis. Go to  98 .

   No

   Repair the open circuit in harness between ignition coil connector and engine grounding terminal.

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor. select [Fuel Pump Relay] of [Active Test].
   NOTE: For detailed procedures, refer to "Active Test". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>ACTIVE TEST .
3. Check if operating sound occurs in the fuel pump according to ON/OFF switching operation.

   Does the fuel pump emit operating sound?

   Yes

   Check the fuel pump and fuel delivery line. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION . Ref. to FUEL INJECTION (FUEL SYSTEMS (H4DO)>FUEL DELIVERY AND EVAPORATION LINES>INSPECTION .

   No

   Go to  53 .

Check fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes

Check fuel pump system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

If the fault occurs after servicing, continue the diagnosis. Go to  93 .

No

Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

Using the Subaru Select Monitor. record the value of [Engine Speed] during cranking.

Does the recorded value of [Engine Speed] contain data of 0 RPM?

Yes

It is possible that temporary fault occurs in the crankshaft position sensor circuit. Check the crankshaft position sensor circuit. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0335 CRANKSHAFT POSITION SENSOR "A" CIRCUIT .

No

Go to  55 .

1. Turn the ignition switch to OFF.
2. Disconnect the connectors from ECM and fuel injectors.
3. Measure the resistance of harness between ECM connector and fuel injector connector.

   Connector & terminal 

   #1 (E158) No. 96 - (E5) No. 1:

   #1 (E158) No. 87 - (E5) No. 2:

   #2 (E158) No. 95 - (E16) No. 1:

   #2 (E158) No. 86 - (E16) No. 2:

   #3 (E158) No. 93 - (E6) No. 1:

   #3 (E158) No. 84 - (E6) No. 2:

   #4 (E158) No. 94 - (E17) No. 1:

   #4 (E158) No. 85 - (E17) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  56 .

   No

   Repair the open circuit of the harness between the ECM connector and fuel injector connector.

Measure the resistance between the ECM connector and engine ground.

Connector & terminal 

#1 (E158) No. 96 - Engine ground:

#1 (E158) No. 87 - Engine ground:

#2 (E158) No. 95 - Engine ground:

#2 (E158) No. 86 - Engine ground:

#3 (E158) No. 93 - Engine ground:

#3 (E158) No. 84 - Engine ground:

#4 (E158) No. 94 - Engine ground:

#4 (E158) No. 85 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .

No

Repair the short circuit to ground in harness between ECM connector and fuel injector connector.

Check the mass air flow and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes

Go to  58 .

No

Go to  77 .

Check the installing condition of the air intake system.

Are there holes. loose bolts or disconnection of hose on air intake system?

Yes

Repair the air intake system. Ref. to INTAKE (INDUCTION) (H4DO)>GENERAL DESCRIPTION .

No

Go to  59 .

Check throttle body. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>THROTTLE BODY>INSPECTION .

Is there any deposit in the throttle body?

Yes

Replace the throttle body. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>THROTTLE BODY .

No

Go to  60 .

1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor. read the values in [VVT Adv. Ang. Amount R]. [VVT Advance Target Angle Amount R]. [VVT Adv. Ang. Amount L]. [VVT Advance Target Angle Amount L]. [Exh. VVT Retard Ang. R]. [Ex VVT Retard Target Angle R]. [Exh. VVT Retard Ang. L] and [Ex VVT Retard Target Angle L].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>FREEZE FRAME DATA .
3. Using the Subaru Select Monitor. compare the respective values between the followings: [VVT Adv. Ang. Amount R] and [VVT Advance Target Angle Amount R]. [VVT Adv. Ang. Amount L] and [VVT Advance Target Angle Amount L]. [Exh. VVT Retard Ang. R] and [Ex VVT Retard Target Angle R]. [Exh. VVT Retard Ang. L] and [Ex VVT Retard Target Angle L].

   Does all of the advance angle amount and retard angle amount synchronize with their target values?

   Yes

   Go to  111 .

   No

   Diagnose the part where there is difference of 10 deg or more.

   • Intake RH: Go to  61 .
   • Intake LH: Go to  65 .
   • Exhaust RH: Go to  69 .
   • Exhaust LH: Go to  73 .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the intake oil control solenoid RH.
3. Turn the ignition switch to ON.
4. Measure the voltage between intake oil control solenoid RH connector and engine ground.

   Connector & terminal 

   (E38) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  62 .

   No

   Repair the following item.

   • Open circuit in harness between M/B and intake oil control solenoid RH connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and intake oil control solenoid RH connector.

   Connector & terminal 

   (E158) No. 99 - (E38) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  63 .

   No

   Repair the open circuit in harness between ECM connector and intake oil control solenoid RH connector.

Measure the resistance between intake oil control solenoid RH connector and engine ground.

Connector & terminal 

(E38) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  64 .

No

Repair the short circuit to ground in harness between ECM connector and intake oil control solenoid RH connector.

Check the intake oil control solenoid RH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes

Replace the intake cam sprocket RH. Ref. to MECHANICAL (H4DO)>CAM SPROCKET .

No

Replace the intake oil control solenoid RH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the intake oil control solenoid LH.
3. Turn the ignition switch to ON.
4. Measure the voltage between intake oil control solenoid LH connector and engine ground.

   Connector & terminal 

   (E37) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  66 .

   No

   Repair the following item.

   • Open circuit in harness between M/B and intake oil control solenoid LH connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and intake oil control solenoid LH.

   Connector & terminal 

   (E158) No. 100 - (E37) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  67 .

   No

   Repair the open circuit in harness between ECM connector and intake oil control solenoid LH connector.

Measure the resistance between intake oil control solenoid LH connector and engine ground.

Connector & terminal 

(E37) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  68 .

No

Repair the short circuit to ground in harness between ECM connector and intake oil control solenoid LH connector.

Check the intake oil control solenoid LH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes

Replace the intake cam sprocket LH. Ref. to MECHANICAL (H4DO)>CAM SPROCKET .

No

Replace the intake oil control solenoid LH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the exhaust oil control solenoid RH.
3. Turn the ignition switch to ON.
4. Measure the voltage between exhaust oil control solenoid RH connector and engine ground.

   Connector & terminal 

   (E63) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  70 .

   No

   Repair the following item.

   • Open circuit in harness between M/B and exhaust oil control solenoid RH connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and exhaust oil control solenoid RH connector.

   Connector & terminal 

   (E158) No. 108 - (E63) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  71 .

   No

   Repair the open circuit in harness between ECM connector and exhaust oil control solenoid RH connector.

Measure the resistance between exhaust oil control solenoid RH connector and engine ground.

Connector & terminal 

(E63) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  72 .

No

Repair the short circuit to ground in harness between ECM connector and exhaust oil control solenoid RH connector.

Check the exhaust oil control solenoid RH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes

Replace the exhaust cam sprocket RH. Ref. to MECHANICAL (H4DO)>CAM SPROCKET .

No

Replace the exhaust oil control solenoid RH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the exhaust oil control solenoid LH.
3. Turn the ignition switch to ON.
4. Measure the voltage between exhaust oil control solenoid LH connector and engine ground.

   Connector & terminal 

   (E66) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  74 .

   No

   Repair the following item.

   • Open circuit in harness between M/B and intake oil control solenoid LH connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and exhaust oil control solenoid LH connector.

   Connector & terminal 

   (E158) No. 109 - (E66) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  75 .

   No

   Repair the open circuit in harness between ECM connector and exhaust oil control solenoid LH connector.

Measure the resistance between exhaust oil control solenoid LH connector and engine ground.

Connector & terminal 

(E66) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  76 .

No

Repair the short circuit to ground in harness between ECM connector and exhaust oil control solenoid LH connector.

Check the exhaust oil control solenoid LH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes

Replace the exhaust cam sprocket LH. Ref. to MECHANICAL (H4DO)>CAM SPROCKET .

No

Replace the exhaust oil control solenoid LH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>OIL CONTROL SOLENOID .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connectors from the mass air flow and intake air temperature sensor.
4. Disconnect the connector from manifold absolute pressure sensor.
5. Measure the resistance of harness between ECM connector and the mass air flow and intake air temperature sensor connector. and between ECM connector and the manifold absolute pressure sensor connector.

   Connector & terminal 

   (B134) No. 32 - (B3) No. 1:

   (B134) No. 54 - (B3) No. 2:

   (B134) No. 53 - (B3) No. 3:

   (B134) No. 43 - (B3) No. 4:

   (E158) No. 58 - (E21) No. 1:

   (E158) No. 69 - (E21) No. 2:

   (E158) No. 41 - (E21) No. 3:

   Is the resistance less than 1 Ω?

   Yes

   Go to  78 .

   No

   Repair the following item.

   • Open circuit in harness between ECM connector and the mass air flow and intake air temperature sensor connector
   • Open circuit of harness between ECM connector and manifold absolute pressure sensor connector
   • Poor contact of J/C

Measure the resistance between the ECM connector and engine ground.

Connector & terminal 

(B134) No. 32 - Engine ground:

(E158) No. 41 - Engine ground:

(B134) No. 43 - Engine ground:

(B134) No. 53 - Engine ground:

(E158) No. 69 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Replace the mass air flow and intake air temperature sensor or the manifold absolute pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MANIFOLD ABSOLUTE PRESSURE SENSOR . If the fault occurs after servicing, continue the diagnosis. Go to  111 .

No

Repair the following item.

• Short circuit to ground in harness between ECM connector and the mass air flow and intake air temperature sensor connector
• Short circuit to ground in harness between ECM connector and manifold absolute pressure sensor connector

Check the engine coolant temperature sensor (inlet) and engine coolant temperature sensor (outlet). Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes

Go to  80 .

No

Replace the defective engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR . If the fault occurs after servicing, replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  122 .

1. Turn the ignition switch to OFF.
2. Disconnect connectors from ECM, engine coolant temperature sensor (inlet) and engine coolant temperature sensor (outlet).
3. Measure the resistance of harness between ECM connector and engine coolant temperature sensor (inlet). and ECM connector and engine coolant temperature sensor (outlet).

   Connector & terminal 

   (E158) No. 58 - (E171) No. 1:

   (E158) No. 55 - (E171) No. 2:

   (E158) No. 58 - (E172) No. 1:

   (E158) No. 59 - (E172) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  81 .

   No

   Repair the open circuit of harness between ECM connector and engine coolant temperature sensor (inlet) or engine coolant temperature sensor (outlet) connector. If the fault occurs after servicing, replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123 .

Measure the resistance between the ECM connector and engine ground.

Connector & terminal 

(E158) No. 55 - Engine ground:

(E158) No. 59 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  82 .

No

Repair the open circuit of harness between ECM connector and engine coolant temperature sensor (inlet) connector or engine coolant temperature sensor (outlet) connector. If the fault occurs after servicing, replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123 .

1. Turn the ignition switch to ON. (Engine OFF)
2. Using the Subaru Select Monitor. read the values in [Long Term Fuel Trim (Bl)] and [Barometric Pressure].
   NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DATA MONITOR .

   Is the value of [Long Term Fuel Trim (Bl)] -25 - 25%? And is the value of [Barometric Pressure] 80 kPa or more?

   Yes

   Go to  85 .

   No

   Go to  83 .

1. Clear the memory of [Engine Control System] using the Subaru Select Monitor or general scan tool. Ref. to COMMON(DIAG)>CLEAR MEMORY .
2. Start the engine.

   Does the engine start?

   Yes

   Go to  84 .

   No

   Go to  85 .

Check the idle speed.

Is the idle speed stable?

Yes

Replace the mass air flow and intake air temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . If the fault occurs after servicing, replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123 .

No

Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR . If the fault occurs after servicing, replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) . If the fault still occurs after replacing the ECM, continue the diagnosis. Go to  123 .

Measure the fuel pressure. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 350 - 450 kPa (3.5 - 4.6 kg/cm² . 50 - 66 psi)?

Yes

Go to  86 .

No

Go to  92 .

Using the Subaru Select Monitor. read the values in [Fuel Rail Pressure A] and [Commanded Fuel Rail Pressure A].

Is the value in [Fuel Rail Pressure A] synchronized with the one in [Commanded Fuel Rail Pressure A] in all freeze frame data?

Yes

Go to  87 .

No

Check the high-pressure fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>HIGH PRESSURE FUEL PUMP>INSPECTION .

Check all spark plugs on all cylinders. Ref. to IGNITION (H4DO)>SPARK PLUG>INSPECTION .

Is the check result OK?

Yes

Go to  88 .

No

• When spark plugs in some cylinders are faulty: Replace the faulty spark plugs of the cylinders. then check the ignition system and fuel system in the faulty cylinders. Ref. to IGNITION (H4DO)>SPARK PLUG . If the fault occurs after servicing, continue the diagnosis. Go to  122 .
• When all spark plugs in all cylinders are faulty: Replace faulty spark plugs in all cylinders. Ref. to IGNITION (H4DO)>SPARK PLUG . If the fault occurs after servicing, continue the diagnosis. Go to  122 .

Check for the condition of fault occurrence.

Does the fault occur only within approx. 15 to 120 minutes after the engine is stopped?

Yes

Go to  90 .

No

• When the fault occurs in two or three minutes or a long time after the engine is stopped: Go to  89 .
• When the fault occurrence pattern is inconsistent: Go to  122 .

Measure the fuel pressure five minutes after the engine is stopped. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 147 kPa (1.5 kg/cm² . 21 psi) or more?

Yes

Go to  122 .

No

Replace the pressure regulator. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL FILTER .

Check the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PURGE CONTROL SOLENOID VALVE>INSPECTION .

Is the check result OK?

Yes

Go to  91 .

No

Replace the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PURGE CONTROL SOLENOID VALVE .

1. After the engine is stopped. scavenge inside of the intake manifold by applying compressed air.
2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.
   NOTE: Remove the vacuum hose between intake manifold and purge solenoid valve and perform the measurement. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>GENERAL DESCRIPTION>COMPONENT>FUEL PIPE .

   Is the HC concentration less than 4000 ppm?

   Yes

   Go to  122 .

   No

   Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

Check fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes

Check fuel pump system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

If the fault occurs after servicing, continue the diagnosis. Go to  122 .

No

Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

Check fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR>INSPECTION .

Is the check result OK?

Yes

Go to  94 .

No

Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

1. Turn the ignition switch to OFF.
2. Disconnect the connectors from ECM and fuel injectors.
3. Measure the resistance of harness between ECM connector and fuel injector connector.

   Connector & terminal 

   #1 (E158) No. 96 - (E5) No. 1:

   #1 (E158) No. 87 - (E5) No. 2:

   #2 (E158) No. 95 - (E16) No. 1:

   #2 (E158) No. 86 - (E16) No. 2:

   #3 (E158) No. 93 - (E6) No. 1:

   #3 (E158) No. 84 - (E6) No. 2:

   #4 (E158) No. 94 - (E17) No. 1:

   #4 (E158) No. 85 - (E17) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  95 .

   No

   Repair the open circuit of the harness between the ECM connector and fuel injector connector.

Measure the resistance between the ECM connector and engine ground.

Connector & terminal 

#1 (E158) No. 96 - Engine ground:

#1 (E158) No. 87 - Engine ground:

#2 (E158) No. 95 - Engine ground:

#2 (E158) No. 86 - Engine ground:

#3 (E158) No. 93 - Engine ground:

#3 (E158) No. 84 - Engine ground:

#4 (E158) No. 94 - Engine ground:

#4 (E158) No. 85 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  96 .

No

Repair the short circuit to ground in harness between ECM connector and fuel injector connector.

1. Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Go to  97 .

1. Replace the camshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CAMSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .

Check the installation condition of crankshaft position sensor.

Is the crankshaft position sensor installed correctly?

Yes

Go to  99 .

No

Install the crankshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

Check the installation condition of camshaft position sensor.

Is the camshaft position sensor installed correctly?

Yes

Go to  100 .

No

Install the camshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CAMSHAFT POSITION SENSOR>INSTALLATION .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the crankshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between crankshaft position sensor connector and engine ground.

   Connector & terminal 

   (E10) No. 3 (+) - Engine ground (-):

   Is the voltage 4.5 V or more?

   Yes

   Go to  101 .

   No

   Repair the power supply circuit.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

   Connector & terminal 

   (E158) No. 66 - (E10) No. 1:

   (E158) No. 68 - (E10) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  102 .

   No

   Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

Measure the resistance between crankshaft position sensor connector and engine ground.

Connector & terminal 

(E10) No. 1 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  103 .

No

Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the intake camshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between intake camshaft position sensor connector and engine ground.

   Connector & terminal 

   (E35) No. 1 (+) - Engine ground (-):

   (E36) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  104 .

   No

   Repair the following item.

   • Open circuit or short circuit to ground in harness between M/B and intake camshaft position sensor connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance between ECM connector and intake camshaft position sensor connector.

   Connector & terminal 

   (E158) No. 77 - (E35) No. 2:

   (E158) No. 51 - (E35) No. 3:

   (E158) No. 78 - (E36) No. 2:

   (E158) No. 51 - (E36) No. 3:

   Is the resistance less than 1 Ω?

   Yes

   Go to  105 .

   No

   Repair the open circuit in the harness between ECM connector and intake camshaft position sensor connector.

Measure the resistance between intake camshaft position sensor connector and engine ground.

Connector & terminal 

(E35) No. 2 - Engine ground:

(E36) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  106 .

No

Repair short circuit to ground in the harness between ECM connector and intake camshaft position sensor connector.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the exhaust camshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between exhaust camshaft position sensor connector and engine ground.

   Connector & terminal 

   (E62) No. 1 (+) - Engine ground (-):

   (E65) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  107 .

   No

   Repair the following item.

   • Open circuit in harness between M/B and exhaust camshaft position sensor connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance between ECM connector and exhaust camshaft position sensor connector.

   Connector & terminal 

   (E158) No. 65 - (E62) No. 2:

   (E158) No. 51 - (E62) No. 3:

   (E158) No. 64 - (E65) No. 2:

   (E158) No. 51 - (E65) No. 3:

   Is the resistance less than 1 Ω?

   Yes

   Go to  108 .

   No

   Repair the open circuit in the harness between ECM connector and exhaust camshaft position sensor connector.

Measure the resistance between exhaust camshaft position sensor connector and engine ground.

Connector & terminal 

(E62) No. 2 - Engine ground:

(E65) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  109 .

No

Repair short circuit to ground in the harness between ECM connector and exhaust camshaft position sensor connector.

1. Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Go to  110 .

1. Replace the camshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CAMSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .

Check the engine coolant temperature sensor (inlet) and engine coolant temperature sensor (outlet). Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes

Go to  112 .

No

Replace the defective engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .

Measure the fuel pressure during cranking or five minutes after the engine is stopped. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the fuel pressure during cranking 325 - 450 kPa (3.3 - 4.6 kg/cm² . 47 - 66 psi). and is the fuel pressure five minutes after engine stop 147 kPa (1.5 kg/cm² . 21 psi) or more?

Yes

Go to  113 .

No

Go to  121 .

1. Turn the ignition switch to ON. (Engine OFF)
2. Using the Subaru Select Monitor. read the value in [Long Term Fuel Trim (Bl)].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>DATA MONITOR .

   Does the value of [Long Term Fuel Trim (Bl)] fall within a range of -15 - 15%?

   Yes

   Go to  114 .

   No

   Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

Start the engine and check the idling speed.

Is the idling speed stable all time?

Yes

It is possible that the fault comes from fuel. Replace fuel.

No

Go to  115 .

Check the installation condition of crankshaft position sensor.

Is the crankshaft position sensor installed correctly?

Yes

Go to  116 .

No

Install the crankshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the crankshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between crankshaft position sensor connector and engine ground.

   Connector & terminal 

   (E10) No. 3 (+) - Engine ground (-):

   Is the voltage 4.5 V or more?

   Yes

   Go to  117 .

   No

   Repair the power supply circuit.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

   Connector & terminal 

   (E158) No. 66 - (E10) No. 1:

   (E158) No. 68 - (E10) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  118 .

   No

   Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

Measure the resistance between crankshaft position sensor connector and engine ground.

Connector & terminal 

(E10) No. 1 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  119 .

No

Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

Check the compression pressure. Ref. to MECHANICAL (H4DO)>COMPRESSION>INSPECTION .

Is the check result OK?

Yes

Go to  120 .

No

Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

1. Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Check the valve timing. Ref. to MECHANICAL (H4DO)>TIMING CHAIN ASSEMBLY .

   When the valve timing is normal. replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .

Check fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes

Check fuel pump system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

No

Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

Measure the fuel pressure during cranking or five minutes after the engine is stopped. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the fuel pressure during cranking 325 - 450 kPa (3.3 - 4.6 kg/cm² . 47 - 66 psi). and is the fuel pressure five minutes after engine stop 147 kPa (1.5 kg/cm² . 21 psi) or more?

Yes

Go to  123 .

No

Go to  130 .

1. Turn the ignition switch to ON. (Engine OFF)
2. Using the Subaru Select Monitor. read the value in [Long Term Fuel Trim-Bank1].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON(DIAG)>DATA MONITOR .

   Does the value of [Long Term Fuel Trim-Bank1] fall within a range of -15 - 15%?

   Yes

   Go to  124 .

   No

   Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

Start the engine and check the idling speed.

Is the idling speed stable all time?

Yes

It is possible that the fault comes from fuel. Replace fuel.

No

Go to  125 .

Check the installation condition of crankshaft position sensor.

Is the crankshaft position sensor installed correctly?

Yes

Go to  126 .

No

Install the crankshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the crankshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between crankshaft position sensor connector and engine ground.

   Connector & terminal 

   (E10) No. 3 (+) - Engine ground (-):

   Is the voltage 4.5 V or more?

   Yes

   Go to  127 .

   No

   Repair the power supply circuit.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

   Connector & terminal 

   (E158) No. 66 - (E10) No. 1:

   (E158) No. 68 - (E10) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  128 .

   No

   Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

Measure the resistance between crankshaft position sensor connector and engine ground.

Connector & terminal 

(E10) No. 1 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  129 .

No

Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

1. Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .

Check fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes

Go to  131 .

No

Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

Check fuel pump circuit. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

Is the check result OK?

Yes

Go to  132 .

No

Repair the fuel pump system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS WITH PHENOMENON>FUEL PUMP CIRCUIT .

Check the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PURGE CONTROL SOLENOID VALVE>INSPECTION .

Is the check result OK?

Yes

Go to  133 .

No

Replace the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PURGE CONTROL SOLENOID VALVE .

1. After the engine is stopped. scavenge inside of the intake manifold by applying compressed air.
2. Measure the HC concentration inside the intake manifold 15 minutes after scavenging is completed.
   NOTE: Remove the vacuum hose between intake manifold and purge solenoid valve and perform the measurement. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>GENERAL DESCRIPTION>COMPONENT>FUEL PIPE .

   Is the HC concentration less than 4000 ppm?

   Yes

   Go to  134 .

   No

   Replace the fuel injector. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL INJECTOR .

Check the intake valve. Ref. to MECHANICAL (H4DO)>CYLINDER HEAD>INSPECTION .

Is there any deposit in the intake valve?

Yes

Clean the intake valve. Ref. to MECHANICAL (H4DO)>CYLINDER HEAD .

No

Go to  135 .

Check the engine coolant temperature sensor (inlet) and engine coolant temperature sensor (outlet). Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes

Go to  136 .

No

Replace the defective engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .

Check the installation condition of crankshaft position sensor.

Is the crankshaft position sensor installed correctly?

Yes

Go to  137 .

No

Install the crankshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR>INSTALLATION .

Check the installation condition of camshaft position sensor.

Is the camshaft position sensor installed correctly?

Yes

Go to  138 .

No

Install the camshaft position sensor correctly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CAMSHAFT POSITION SENSOR>INSTALLATION .

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the crankshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between crankshaft position sensor connector and engine ground.

   Connector & terminal 

   (E10) No. 3 (+) - Engine ground (-):

   Is the voltage 4.5 V or more?

   Yes

   Go to  139 .

   No

   Repair the power supply circuit.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and crankshaft position sensor connector.

   Connector & terminal 

   (E158) No. 66 - (E10) No. 1:

   (E158) No. 68 - (E10) No. 2:

   Is the resistance less than 1 Ω?

   Yes

   Go to  140 .

   No

   Repair the open circuit in the harness between the ECM connector and crankshaft position sensor connector.

Measure the resistance between crankshaft position sensor connector and engine ground.

Connector & terminal 

(E10) No. 1 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  141 .

No

Repair short circuit to ground in harness between ECM connector and crankshaft position sensor connector.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the intake camshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between intake camshaft position sensor connector and engine ground.

   Connector & terminal 

   (E35) No. 1 (+) - Engine ground (-):

   (E36) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  142 .

   No

   Repair the following item.

   • Open circuit or short circuit to ground in harness between M/B and intake camshaft position sensor connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance between ECM connector and intake camshaft position sensor connector.

   Connector & terminal 

   (E158) No. 77 - (E35) No. 2:

   (E158) No. 51 - (E35) No. 3:

   (E158) No. 78 - (E36) No. 2:

   (E158) No. 51 - (E36) No. 3:

   Is the resistance less than 1 Ω?

   Yes

   Go to  143 .

   No

   Repair the open circuit in the harness between ECM connector and intake camshaft position sensor connector.

Measure the resistance between intake camshaft position sensor connector and engine ground.

Connector & terminal 

(E35) No. 2 - Engine ground:

(E36) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  144 .

No

Repair short circuit to ground in the harness between ECM connector and intake camshaft position sensor connector.

1. Turn the ignition switch to OFF.
2. Disconnect the connector from the exhaust camshaft position sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between exhaust camshaft position sensor connector and engine ground.

   Connector & terminal 

   (E62) No. 1 (+) - Engine ground (-):

   (E65) No. 1 (+) - Engine ground (-):

   Is the voltage 10 V or more?

   Yes

   Go to  145 .

   No

   Repair the following item.

   • Open circuit in harness between main relay and exhaust camshaft position sensor connector
   • Poor contact of coupling connector

1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance between ECM connector and exhaust camshaft position sensor connector.

   Connector & terminal 

   (E158) No. 65 - (E62) No. 2:

   (E158) No. 51 - (E62) No. 3:

   (E158) No. 64 - (E65) No. 2:

   (E158) No. 51 - (E65) No. 3:

   Is the resistance less than 1 Ω?

   Yes

   Go to  146 .

   No

   Repair the open circuit in the harness between ECM connector and exhaust camshaft position sensor connector.

Measure the resistance between exhaust camshaft position sensor connector and engine ground.

Connector & terminal 

(E62) No. 2 - Engine ground:

(E65) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes

Go to  147 .

No

Repair short circuit to ground in the harness between ECM connector and exhaust camshaft position sensor connector.

Check the compression pressure. Ref. to MECHANICAL (H4DO)>COMPRESSION>INSPECTION .

Is the check result OK?

Yes

Go to  148 .

No

Check the engine. Ref. to MECHANICAL (H4DO)>SYMPTOMS AND CAUSES>INSPECTION .

1. Replace the crankshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CRANKSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Go to  149 .

1. Replace the camshaft position sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>CAMSHAFT POSITION SENSOR .
2. Check that the fault is removed.

   Is the fault removed?

   Yes

   Clear the memory to complete. Ref. to COMMON(DIAG)>CLEAR MEMORY .

   No

   Check the valve timing. Ref. to MECHANICAL (H4DO)>TIMING CHAIN ASSEMBLY .

   When the valve timing is normal, replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM) .