DTC P1603: Engine Stall History: Notes

DTC detecting condition:

Immediately at fault recognition

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Ref. to ENGINE (DIAGNOSTICS) (H4DO)>INSPECTION MODE>PROCEDURE .
Use the check board when measuring the ECM terminal voltage and resistance.

NOTE: This DTC may be detected even if fault does not occur in the vehicle. If the customer does not ask for inspection, perform the clear memory mode without inspection and return the vehicle to the user.

Wiring diagram:

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

G12411504

Courtesy of SUBARU OF AMERICA, INC.

G12409955

Courtesy of SUBARU OF AMERICA, INC.

G11583324

Courtesy of SUBARU OF AMERICA, INC.

G12411507

Courtesy of SUBARU OF AMERICA, INC.

G12411508

Courtesy of SUBARU OF AMERICA, INC.

G12409961

Courtesy of SUBARU OF AMERICA, INC.

CHECK DTC .
Read the engine DTC using the Subaru Select Monitor or general scan tool. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

Is other than DTC P1603 displayed? (Current malfunction)

Yes: Check DTC using "List of Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

No: Go to 2 .
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the value in «Fuel Level».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine", Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Fuel Level» 16.4% or more?

Yes: Go to 3 .

No: Fuel may be run out. If the fault occurs after refueling, continue the diagnosis. Go to 3 .
CHECK FREEZE FRAME DATA .
Read the value of «Control module voltage» using Subaru Select Monitor.

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Control module voltage» 11 V or more?

Yes: Go to 4 .

No: Check the battery and generator. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>BATTERY>INSPECTION . Ref. to STARTING/CHARGING SYSTEMS (H4DO)>GENERATOR>INSPECTION .
CHECK FOR MALFUNCTION OCCURRENCE .
Did you ask the customer about the driving condition and engine speed status when the fault occurred?

Yes:
- The engine speed dropped slowly and then the engine stalled during idling or deceleration: Go to 5 .
- The engine speed dropped rapidly and then the engine stalled during idling or deceleration: Go to 67 .
- The engine stalled during standing start, acceleration, or constant speed driving: Go to 76 .
No: Ask the customer about the driving condition and engine speed status when fault occurred.
CHECK FREEZE FRAME DATA .
1. Read the values of «Short term fuel trim B1» and «Long term fuel trim B1», using the Subaru Select Monitor.
  NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
2. Obtain the sum values of «Short term fuel trim B1» and «Long term fuel trim B1» in each freeze frame data.
Is the sum value of «Short term fuel trim B1» and «Long term fuel trim B1» within ±15% in each freeze frame data?

Yes: Go to 49 .

No:
- More than 15% in each freeze frame data: Go to 6 .
- Less than -15% in any one of freeze frame data: Go to 34 .
CHECK AIR INTAKE SYSTEM .
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 7 .
CHECK PURGE CONTROL SOLENOID VALVE .
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 8 .

No: Replace the purge control solenoid valve. Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PURGE CONTROL SOLENOID VALVE .
CHECK FREEZE FRAME DATA .
Read the value of «Stop Light Switch» using Subaru Select Monitor.

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Does the value of «Stop Light Switch» indicate OFF in all freeze frame data?

Yes: Go to 11 .

No: Go to 9 .
CHECK CURRENT DATA .
1. Start the engine and warm up completely.
2. Read the value of «Short term fuel trim B1» both when the brake pedal is released and depressed using Subaru Select Monitor.
  NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
Does the value of «Short term fuel trim B1» with the brake pedal depressed increase by 10% or more compared to when the pedal is released?

Yes: Replace the brake booster. Ref. to BRAKE>BRAKE BOOSTER .

No: Go to 10 .
CHECK CURRENT DATA .
1. Start the engine and warm up completely.
2. While reproducing the faulty condition of the vehicle, read the values of «Short term fuel trim B1» and «Long term fuel trim B1» using the Subaru Select Monitor.
  NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
3. Obtain the sum values of «Short term fuel trim B1» and «Long term fuel trim B1».
Is the sum value of «Short term fuel trim B1» and «Long term fuel trim B1» within ±15%?

Yes: Go to 11 .

No: Replace the brake booster. Ref. to BRAKE>BRAKE BOOSTER .
CHECK IGNITION SYSTEM .
Check the ignition system. Ref. to ENGINE (DIAGNOSTICS)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 12 .

No: Repair the ignition system. Ref. to IGNITION (H4DO)>GENERAL DESCRIPTION .
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
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 13 .

No: 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 .
CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR .
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. Measure the resistance of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
  Connector & terminal
  
  (B134) No. 16 - (B3) No. 5:
  
  (B134) No. 17 - (B3) No. 4:
Is the resistance less than 1 Ω?

Yes: Go to 14 .

No: Repair the open circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(B134) No. 16 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 15 .

No: Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
CHECK CURRENT DATA .
1. Start the engine and warm up completely.
2. Using the Subaru Select Monitor, read the value of «Calculated load value», then compare it with the reference value of «Calculated load value» listed in "Engine Current Data Display" in "Subaru Select Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
  NOTE:
  - The value of «Calculated load value» change depending on how the engine internal parts settle in. If the value is out of standard, judge it again by comparing the vehicle with another one with the same specifications and similar conditions such as travel distance.
  - For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
Does the value of «Calculated load value» falls between 90 - 110% of the value described in the list?

Yes: Go to 16 .

No: 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 .
CHECK FRONT OXYGEN (A/F) SENSOR DATA .
1. Start the engine and warm up completely.
2. Raise the engine speed up to 2, 500 rpm and maintain it for approx. three minutes.
3. Release the accelerator pedal and idle the engine.
4. Using «Injection Quantity Control» in the «Active Test» item, read the value of «A/F Sensor #1» at the increase rate of both 12% and -12%.
  NOTE:
  - Perform the operation immediately after the engine comes into idling condition, otherwise the front oxygen (A/F) sensor will be cooled.
  - For detailed operation procedures, refer to the "Active Test". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>ACTIVE TEST .
Does the value of «A/F Sensor #1» change to less than 0.88 at the increase rate of 12%, and to 1.12 or more at the rate of -12%?

Yes: Go to 20 .

No: Go to 17 .
CHECK POWER SUPPLY TO FRONT OXYGEN (A/F) SENSOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connectors from front oxygen (A/F) sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between front oxygen (A/F) sensor connector and engine ground.
  Connector & terminal
  
  (E24) No. 2 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 18 .

No: Repair the power supply line.
NOTE:
In this case, repair the following item:
- Open circuit of harness between M/B main relay and front oxygen (A/F) sensor connector
- Poor contact of M/B main relay connector
- Poor contact of coupling connector
- Defective M/B main relay
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector.
  Connector & terminal
  
  (E158) No. 5 - (E24) No. 1:
  
  (E158) No. 33 - (E24) No. 4:
  
  (E158) No. 46 - (E24) No. 3:
Is the resistance less than 1 Ω?

Yes: Go to 19 .

No: Repair the open circuit of harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E158) No. 5 - Engine ground:

(E158) No. 33 - Engine ground:

(E158) No. 46 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 20 .

No: Repair the short circuit to ground in harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the values in «Coolant Temp.» and «Ambient Temperature».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Coolant Temp.» 120°C (248°F) or more? Or, is the value of «Coolant Temp.» lower than «Ambient Temperature» by 15°C (27°F) or more?

Yes: Go to 21 .

No: Go to 24 .
CHECK ENGINE COOLANT TEMPERATURE SENSOR .
Check the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 22 .

No: Replace the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .
CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connectors from the engine coolant temperature sensor.
4. Measure the resistance of harness between ECM connector and engine coolant temperature sensor connector.
  Connector & terminal
  
  (E158) No. 34 - (E8) No. 1:
  
  (E158) No. 43 - (E8) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 23 .

No: Repair the open circuit of the harness between the ECM connector and engine coolant temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E158) No. 43 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 24 .

No: Repair the short circuit to ground in harness between ECM connector and engine coolant temperature sensor connector.
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the value in «Evap Purge Flow».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Evap Purge Flow» 0% in all freeze frame data?

Yes: Go to 30 .

No: Go to 25 .
CHECK PURGE CONTROL SOLENOID VALVE .
1. Select «CPC Solenoid Valve» from "Actuator ON/OFF Operation" in "Active Test".
  NOTE: For detailed operation procedures, refer to the "Active Test". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>ACTIVE TEST .
2. Check if the ventilation changes according to ON/OFF switching operation.
Does the ventilation of purge control solenoid valve change correctly?

Yes: Go to 30 .

No: Go to 26 .
CHECK POWER SUPPLY TO PURGE CONTROL SOLENOID VALVE CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the purge control solenoid valve.
3. Turn the ignition switch to ON.
4. Measure the voltage between purge control solenoid valve connector and engine ground.
  Connector & terminal
  
  (E4) No. 1 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 27 .

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and purge control solenoid valve connector.
  Connector & terminal
  
  (E158) No. 51 - (E4) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 28 .

No: Repair the open circuit in harness between ECM connector and purge control solenoid valve connector.
CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE CONNECTOR .
Measure the resistance between the purge control solenoid valve connector and engine ground.

Connector & terminal

(E4) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 29 .

No: Repair the ground short circuit of harness between ECM connector and purge control solenoid valve 1 connector.
CHECK FOR POOR CONTACT .
Check for poor contact of ECM connector.

Is there poor contact of ECM connector?

Yes: Repair the poor contact of ECM connector.

No: Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE CONTROL MODULE (ECM)
CHECK OF FUEL PUMP .
1. On the "Active Test" item, select «Fuel Pump Control (ON/OFF Dr.)» and perform ON/OFF switching.
  NOTE: For detailed operation procedures, refer to the "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 32 .

No: Go to 31 .
CHECK OF FUEL PUMP .
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 FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

No: Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .
CHECK FUEL TANK .
WARNING: Place "NO OPEN FLAMES" signs near the working area.

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 33 .
CHECK FUEL PRESSURE .
WARNING: Place "NO OPEN FLAMES" signs near the working area.
CAUTION:
- Be careful not to spill fuel.
- Before attaching/detaching a fuel pressure gauge, release the fuel pressure.
Measure the fuel pressure. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 340 - 400 kPa (3.5 - 4.1 kgf/cm² , 49 - 58 psi)?

Yes: Perform the Clear Memory Mode to complete. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE .

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 .
CHECK IGNITION SYSTEM .
Check the ignition system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 35 .

No: Repair the ignition system. Ref. to IGNITION (H4DO)>GENERAL DESCRIPTION .
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the value of «Calculated load value», then compare it with the reference value of «Calculated load value» listed in "Engine Current Data Display" in "Subaru Select Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
NOTE:
- The value of «Calculated load value» change depending on how the engine internal parts settle in. If the value is out of standard, judge it again by comparing the vehicle with another one with the same specifications and similar conditions such as travel distance.
- For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
Is the value of «Calculated load value» 110% or more of the value described in the list?

Yes: Go to 36 .

No: Go to 40 .
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
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 37 .

No: 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 .
CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR .
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. Measure the resistance of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
  Connector & terminal
  
  (B134) No. 16 - (B3) No. 5:
  
  (B134) No. 17 - (B3) No. 4:
Is the resistance less than 1 Ω?

Yes: Go to 38 .

No: Repair the open circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(B134) No. 16 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 39 .

No: Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
CHECK CURRENT DATA .
1. Start the engine and warm up completely.
2. Using the Subaru Select Monitor, read the value of «Calculated load value», then compare it with the reference value of «Calculated load value» listed in "Engine Current Data Display" in "Subaru Select Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
  NOTE:
  - The value of «Calculated load value» change depending on how the engine internal parts settle in. If the value is out of standard, judge it again by comparing the vehicle with another one with the same specifications and similar conditions such as travel distance.
  - For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
Does the value of «Calculated load value» falls between 90 - 110% of the value described in the list?

Yes: Go to 40 .

No: 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 .
CHECK CURRENT DATA .
1. Start the engine and warm up completely.
2. Raise the engine speed up to 2, 500 rpm and maintain it for approx. three minutes.
3. Release the accelerator pedal and idle the engine.
4. Using «Injection Quantity Control» in the «Active Test» item, read the value of «A/F Sensor #1» at the increase rate of both 12% and -12%.
  NOTE:
  - Perform the operation immediately after the engine comes into idling condition, otherwise the front oxygen (A/F) sensor will be cooled.
  - For detailed operation procedures, refer to the "Active Test". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>ACTIVE TEST .
Does the value of «A/F Sensor #1» change to less than 0.88 at the increase rate of 12%, and to 1.12 or more at the rate of -12%?

Yes: Go to 45 .

No: Go to 41 .
CHECK FREEZE FRAME DATA .
Read the value of «A/F Sensor #1 Resistance» using the Subaru Select Monitor.

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «A/F Sensor #1 Resistance» 500 ft or more?

Yes: Replace the front oxygen (A/F) sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FRONT OXYGEN (A/F) SENSOR .

No: Go to 42 .
CHECK POWER SUPPLY TO FRONT OXYGEN (A/F) SENSOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connectors from front oxygen (A/F) sensor.
3. Turn the ignition switch to ON.
4. Measure the voltage between front oxygen (A/F) sensor connector and engine ground.
  Connector & terminal
  
  (E24) No. 2 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 43 .

No: Repair the power supply line.
NOTE:
In this case, repair the following item:
- Open circuit of harness between M/B main relay and front oxygen (A/F) sensor connector
- Poor contact of M/B main relay connector
- Poor contact of coupling connector
- Defective M/B main relay
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the resistance of harness between ECM connector and front oxygen (A/F) sensor connector.
  Connector & terminal
  
  (E158) No. 5 - (E24) No. 1:
  
  (E158) No. 33 - (E24) No. 4:
  
  (E158) No. 46 - (E24) No. 3:
Is the resistance less than 1 Ω?

Yes: Go to 44 .

No: Repair the open circuit of harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E158) No. 5 - Engine ground:

(E158) No. 33 - Engine ground:

(E158) No. 46 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 45 .

No: Repair the short circuit to ground in harness between ECM connector and front oxygen (A/F) sensor connector.
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the values in «Coolant Temp.» and «Ambient Temperature».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Coolant Temp.» 120°C (248°F) or more? Or, is the value of «Coolant Temp.» lower than «Ambient Temperature» by 15°C (27°F) or more?

Yes: Go to 46 .

No: Perform the Clear Memory Mode to complete. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE .
CHECK ENGINE COOLANT TEMPERATURE SENSOR .
Check the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 47 .

No: Replace the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .
CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connectors from the engine coolant temperature sensor.
4. Measure the resistance of harness between ECM connector and engine coolant temperature sensor connector.
  Connector & terminal
  
  (E158) No. 34 - (E8) No. 1:
  
  (E158) No. 43 - (E8) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 48 .

No: Repair the open circuit of the harness between the ECM connector and engine coolant temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E158) No. 43 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Even if DTC is detected, it has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

No: Repair the short circuit to ground in harness between ECM connector and engine coolant temperature sensor connector.
CHECK IGNITION SYSTEM .
Check the ignition system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 50 .

No: Repair the ignition system. Ref. to IGNITION (H4DO)>GENERAL DESCRIPTION .
CHECK FREEZE FRAME DATA .
1. Using Subaru Select Monitor, read the values of «Idle Mass Air Flow Feedback correct», «ISC Learning Value» and «Idle dirty throttle correct» in freeze frame data.
  NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
2. Obtain the sum value of «Idle Mass Air Flow Feedback correct», «ISC Learning Value» and «Idle dirty throttle correct».
3. Start the engine and warm up completely.
4. Using Subaru Select Monitor, read the values of «Idle Mass Air Flow Feedback correct», «ISC Learning Value» and «Idle dirty throttle correct» in current data at normal idling.
  NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
5. Obtain the sum value of «Idle Mass Air Flow Feedback correct», «ISC Learning Value» and «Idle dirty throttle correct».
Is the sum value of freeze frame data less than 80% of the sum value of current data?

Yes: Go to 51 .

No: Go to 53 .
CHECK AIR INTAKE SYSTEM .
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 52 .
CHECK AIR INTAKE SYSTEM .
Check the air intake system related parts.
- Brake booster: Ref. to BRAKE>BRAKE BOOSTER>INSPECTION .
- Mass air flow and intake air temperature sensor: Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .
- PCV hose: Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PCV HOSE>INSPECTION .
- PCV valve: Ref. to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (H4DO)>PCV VALVE>INSPECTION .
- 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 62 .

No: Replace the parts if defective.
CHECK FREEZE FRAME DATA .
1. Using Subaru Select Monitor, read the values of «VVT Adv. Ang. Amount R», «VVT Advance Target Angle Amount R» and «VVT Adv. Ang. Amount L» and «VVT Advance Target Angle Amount L».
  NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
2. Using Subaru Select Monitor, compare the respective values between the followings: «VVT Adv. Ang. Amount R», «VVT Advance Target Angle Amount R», «VVT Adv. Ang. Amount L» and «VVT Advance Target Angle Amount L».
Does all of the advance angle amount and retard angle amount synchronize with their target values?

Yes: Go to 62 .

No: Diagnose the part that does not synchronize.
- Intake RH: Go to 54 .
- Intake LH: Go to 58 .
CHECK POWER SUPPLY TO THE INTAKE OIL CONTROL SOLENOID RH .
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 55 .

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND INTAKE OIL CONTROL SOLENOID RH 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 & terminal
  
  (E158) No. 20 - (E38) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 56 .

No: Repair the open circuit in harness between ECM connector and intake oil control solenoid RH connector.
CHECK HARNESS BETWEEN ECM 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 57 .

No: Repair the short circuit to ground in harness between ECM connector and intake oil control solenoid RH connector.
CHECK INTAKE OIL CONTROL SOLENOID RH .
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 .
CHECK POWER SUPPLY TO THE INTAKE OIL CONTROL SOLENOID LH .
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 59 .

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND INTAKE OIL CONTROL SOLENOID LH 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. 6 - (E37) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 60 .

No: Repair the open circuit in harness between ECM connector and intake oil control solenoid LH connector.
CHECK HARNESS BETWEEN ECM 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 61 .

No: Repair the short circuit to ground in harness between ECM connector and intake oil control solenoid LH connector.
CHECK INTAKE OIL CONTROL SOLENOID LH .
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 .
CHECK ENGINE COOLANT TEMPERATURE SENSOR .
Check the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 63 .

No: Replace the engine coolant temperature sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>ENGINE COOLANT TEMPERATURE SENSOR .
CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connectors from the engine coolant temperature sensor.
4. Measure the resistance of harness between ECM connector and engine coolant temperature sensor connector.
  Connector & terminal
  
  (E158) No. 34 - (E8) No. 1:
  
  (E158) No. 43 - (E8) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 64 .

No: Repair the open circuit of the harness between the ECM connector and engine coolant temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(E158) No. 43 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 65 .

No: Repair the short circuit to ground in harness between ECM connector and engine coolant temperature sensor connector.
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
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 66 .

No: 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 .
CHECK MANIFOLD ABSOLUTE PRESSURE SENSOR .
Check the manifold absolute pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MANIFOLD ABSOLUTE PRESSURE SENSOR .

Is the check result OK?

Yes: Perform the Clear Memory Mode to complete. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE .

No: Check the manifold absolute pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>MANIFOLD ABSOLUTE PRESSURE SENSOR .
CHECK POWER SUPPLY CIRCUIT OF FUEL INJECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from fuel injector.
3. Turn the ignition switch to ON.
4. Measure the voltage between fuel injector connector and the engine ground.
  Connector & terminal
  
  (E5) No. 2 (+) - Engine ground (-):
  
  (E16) No. 2 (+) - Engine ground (-):
  
  (E6) No. 2 (+) - Engine ground (-):
  
  (E17) No. 2 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 68 .

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from fuel injector.
4. Measure the resistance of harness between ECM connector and fuel injector connector.
  Connector & terminal
  
  #1 (E158) No. 23 - (E5) No. 1:
  
  #2 (E158) No. 8 - (E16) No. 1:
  
  #3 (E158) No. 9 - (E6) No. 1:
  
  #4 (E158) No. 22 - (E17) No. 1:
Is the resistance less than 1 Ω?

Yes: Go to 69 .

No: Repair the open circuit of the harness between the ECM connector and fuel injector connector.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

#1 (E158) No. 23 - Engine ground:

#2 (E158) No. 8 - Engine ground:

#3 (E158) No. 9 - Engine ground:

#4 (E158) No. 22 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 70 .

No: Repair the short circuit to ground in harness between ECM connector and fuel injector connector.
CHECK IGNITION SYSTEM .
Check the ignition system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 71 .

No: Repair the ignition system. Ref. to IGNITION (H4DO)>GENERAL DESCRIPTION .
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the value of «A/C Compressor Signal».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine", Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «A/C Compressor Signal» ON output?

Yes: Go to 72 .

No: Go to 73 .
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the value of «Idle A/C load correct».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Idle A/C load correct» increasing?

Yes: Check the air conditioner. Ref. to HVAC SYSTEM (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON . Ref. to BODY CONTROL SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

No: Go to 73 .
CHECK FREEZE FRAME DATA .
1. Using the Subaru Select Monitor, read the value of «Electric Load Feedback Val».
  NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
2. Compare the value of «Electric Load Feedback Val» with that of «Idle Mass Air Flow», which is described in "Engine Current Data Display". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
  NOTE: For detailed operation procedures, refer to "Current Data Display For Engine", Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
Is the value of «Electric Load Feedback Val» 20% or more than «Idle Mass Air Flow»?

Yes: Check the generator and power assisted system. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>GENERATOR>INSPECTION . Ref. to POWER ASSISTED SYSTEM (POWER STEERING) (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

No: Go to 74 .
CHECK FREEZE FRAME DATA .
1. Using the Subaru Select Monitor, read the values of «Vehicle Speed», «Engine Speed» and «AT turbine speed».
  NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine", Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
Is there any freeze frame data indicating that the value of «Vehicle Speed» is less than 6 km/h (18.6 MPH), and that the difference in values between «Engine Speed» and «AT turbine speed» is less than 100 rpm?

Yes: Repair the CVT. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION(TR580)>GENERAL DESCRIPTION .

No: Go to 75 .
CHECK DTC .
Read the engine DTC using the Subaru Select Monitor or general scan tool. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

Is DTC of CVT displayed? (Current malfunction) Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .

Yes: Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)".

Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

No: Even if DTC is detected, it has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK FREEZE FRAME DATA .
Using the Subaru Select Monitor, read the values in «Calculated load value» and «Relative Throttle Pos.».

NOTE: For detailed operation procedures, refer to "Freeze Frame Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

Is the value of «Calculated load value» decreasing while that of «Relative Throttle Pos.» is increasing?

Yes: Go to 77 .

No: Go to 81 .
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
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 78 .

No: 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 .
CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR .
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. Measure the resistance of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
  Connector & terminal
  
  (B134) No. 16 - (B3) No. 5:
  
  (B134) No. 17 - (B3) No. 4:
Is the resistance less than 1 Ω?

Yes: Go to 79 .

No: Repair the open circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
CHECK HARNESS BETWEEN ECM AND MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

(B134) No. 16 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 80 .

No: Repair the ground short circuit of harness between ECM connector and the mass air flow and intake air temperature sensor connector.
CHECK CURRENT DATA .
1. Start the engine and warm up completely.
2. Using the Subaru Select Monitor, read the value of «Calculated load value», then compare it with the reference value of «Calculated load value» listed in "Engine Current Data Display" in "Subaru Select Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
  NOTE:
  - The value of «Calculated load value» change depending on how the engine internal parts settle in. If the value is out of standard, judge it again by comparing the vehicle with another one with the same specifications and similar conditions such as travel distance.
  - For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
Does the value of «Calculated load value» falls between 90 - 110% of the value described in the list?

Yes: Go to 81 .

No: 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 .
CHECK POWER SUPPLY CIRCUIT OF FUEL INJECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from fuel injector.
3. Turn the ignition switch to ON.
4. Measure the voltage between fuel injector connector and the engine ground.
  Connector & terminal
  
  (E5) No. 2 (+) - Engine ground (-):
  
  (E16) No. 2 (+) - Engine ground (-):
  
  (E6) No. 2 (+) - Engine ground (-):
  
  (E17) No. 2 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 82 .

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from fuel injector.
4. Measure the resistance of harness between ECM connector and fuel injector connector.
  Connector & terminal
  
  #1 (E158) No. 23 - (E5) No. 1:
  
  #2 (E158) No. 8 - (E16) No. 1:
  
  #3 (E158) No. 9 - (E6) No. 1:
  
  #4 (E158) No. 22 - (E17) No. 1:
Is the resistance less than 1 Ω?

Yes: Go to 83 .

No: Repair the open circuit of the harness between the ECM connector and fuel injector connector.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR .
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

#1 (E158) No. 23 - Engine ground:

#2 (E158) No. 8 - Engine ground:

#3 (E158) No. 9 - Engine ground:

#4 (E158) No. 22 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 84 .

No: Repair the short circuit to ground in harness between ECM connector and fuel injector connector.
CHECK IGNITION SYSTEM .
Check the ignition system. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 85 .

No: Repair the ignition system. Ref. to IGNITION (H4DO)>GENERAL DESCRIPTION .
CHECK OF FUEL PUMP .
1. On the "Active Test" item, select «Fuel Pump Control (ON/OFF Dr.)» and perform ON/OFF switching.
  NOTE: For detailed operation procedures, refer to the "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 87 .

No: Go to 86 .
CHECK OF FUEL PUMP .
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 FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .

No: Replace the fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>FUEL PUMP .
CHECK FUEL TANK .
WARNING: Place "NO OPEN FLAMES" signs near the working area.

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 88 .
CHECK FUEL PRESSURE .
WARNING: Place "NO OPEN FLAMES" signs near the working area.
CAUTION:
- Be careful not to spill fuel.
- Before attaching/detaching a fuel pressure gauge, release the fuel pressure.
Measure the fuel pressure. Ref. to MECHANICAL (H4DO)>FUEL PRESSURE>INSPECTION .

Is the measured value 340 - 400 kPa (3.5 - 4.1 kgf/cm² , 49 - 58 psi)?

Yes: Go to 89 .

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 .
CHECK ENGINE RUNNING CONDITION .
Check the engine running condition using "Roughness monitor" in the Subaru Select Monitor.

NOTE: For detailed operation procedures, refer to "Application help".

Is there a large difference in the speed between each cylinder?

Yes: It is possible that the compression pressure of the engine is not sufficient. Check the engine. Ref. to MECHANICAL (H4DO)>ENGINE TROUBLE IN GENERAL>INSPECTION .

No: Perform the Clear Memory Mode to complete. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>CLEAR MEMORY MODE .