DTC P1603: Engine Stall History: Notes

DTC detecting condition:

Immediately at fault recognition

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE>OPERATION ..
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 Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

G11577062

Courtesy of SUBARU OF AMERICA, INC.

G11577046

Courtesy of SUBARU OF AMERICA, INC.

G09480903

Courtesy of SUBARU OF AMERICA, INC.

G11577188

Courtesy of SUBARU OF AMERICA, INC.

G11577042

Courtesy of SUBARU OF AMERICA, INC.

G11577043

Courtesy of SUBARU OF AMERICA, INC.

G11577041

Courtesy of SUBARU OF AMERICA, INC.

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

Is other than DTC P1603 displayed? (Current malfunction)

Yes: Check DTC using "List of Diagnostic Trouble Code (DTC)". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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. Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>BATTERY>INSPECTION . Refer to STARTING/CHARGING SYSTEMS (EXCEPT FOR STI)>GENERATOR>INSPECTION .
CHECK FOR MALFUNCTION OCCURRENCE.
Check "Check List for Interview".

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 82.
- The engine stalled during standing start, acceleration, or constant speed driving: Go to 89.
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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 56.

No
- More than 15% in each freeze frame data: Go to 6.
- Less than -15% in any one of freeze frame data: Go to 40.
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. Refer to INTAKE (INDUCTION) (EXCEPT FOR STI)>GENERAL DESCRIPTION .

No: Go to 7.
CHECK PURGE CONTROL SOLENOID VALVE.
Check purge control solenoid valve 1 and purge control solenoid valve 2. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE>INSPECTION .

Is the check result OK?

Yes: Go to 8.

No: Replace the faulty purge control solenoid valve. Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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. Refer 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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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. Refer to BRAKE>BRAKE BOOSTER .
CHECK IGNITION SYSTEM.
Check the ignition system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 12.

No: Repair the ignition system. Refer to IGNITION (EXCEPT FOR STI)>GENERAL DESCRIPTION .
CHECK FREEZE FRAME DATA.
Read the value of «A/F Sensor #1» using the Subaru Select Monitor.

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

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

Yes: Go to 17.

No: Go to 13.
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR.
Check the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 14.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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. 3:
  
  (B134) No. 28 - (B3) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 15.

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:

(B134) No. 28 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 16.

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. Compare with the reference value of «Load Value» described in "Engine Current Data Display" under "Subaru Select Monitor". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 21.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 21.

No: Go to 18.
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. 3 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 19.

No: Repair the power supply line.
NOTE:
In this case, repair the following item:
- Open circuit in harness between A/F, oxygen sensor relay and front oxygen (A/F) sensor connector
- Poor contact of A/F, oxygen sensor relay connector
- Poor contact of coupling connector
- Malfunction of A/F, oxygen sensor 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. 15 - (E24) No. 1:
  
  (E158) No. 27 - (E24) No. 4:
  
  (E158) No. 39 - (E24) No. 5:
  
  (E159) No. 9 - (E24) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 20.

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. 15 - Engine ground:

(E158) No. 27 - Engine ground:

(E158) No. 39 - Engine ground:

(E159) No. 9 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 21.

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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 22.

No: Go to 25.
CHECK ENGINE COOLANT TEMPERATURE SENSOR.
Check the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 23.

No: Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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
  
  (E159) No. 27 - (E8) No. 1:
  
  (E158) No. 38 - (E8) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 24.

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. 38 - Engine ground:

(E159) No. 27 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 25.

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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 35.

No: Go to 26.
CHECK PURGE CONTROL SOLENOID VALVE 1.
1. On the «Active Test» item, select «CPC Solenoid Valve», and perform ON/OFF.
  NOTE: For detailed operation procedures, refer to the "Active Test". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>ACTIVE TEST .
2. Check if the ventilation changes according to ON/OFF switching operation.
Does the ventilation of purge control solenoid valve 1 change correctly?

Yes: Go to 30.

No: Go to 27.
CHECK POWER SUPPLY TO PURGE CONTROL SOLENOID VALVE 1 CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connector from purge control solenoid valve 1.
3. Turn the ignition switch to ON.
4. Measure the voltage between purge control solenoid valve 1 connector and engine ground.
  Connector & terminal
  
  (E4) No. 1 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 28.

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE 1 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 1 connector.
  Connector & terminal
  
  (E159) No. 4 - (E4) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 29.

No: Repair the open circuit in harness between ECM connector and purge control solenoid valve 1 connector.
CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE 1 CONNECTOR.
Measure the resistance between the purge control solenoid valve 1 connector and engine ground.

Connector & terminal

(E4) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 30.

No: Repair the ground short circuit of harness between ECM connector and purge control solenoid valve 1 connector.
CHECK PURGE CONTROL SOLENOID VALVE 2.
1. Connect all connectors.
2. On the «Active Test» item, select «CPC Solenoid 2», and perform ON/OFF.
  NOTE: For detailed operation procedures, refer to the "Active Test". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>ACTIVE TEST .
3. Check if the ventilation changes according to ON/OFF switching operation.
Does the ventilation of purge control solenoid valve 2 change correctly?

Yes: Go to 35.

No: Go to 31.
CHECK POWER SUPPLY TO PURGE CONTROL SOLENOID VALVE 2 CONNECTOR.
1. Turn the ignition switch to OFF.
2. Disconnect the connector from purge control solenoid valve 2.
3. Turn the ignition switch to ON.
4. Measure the voltage between purge control solenoid valve 2 connector and engine ground.
  Connector & terminal
  
  (E52) No. 1 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 32.

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE 2 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 2 connector.
  Connector & terminal
  
  (E159) No. 12 - (E52) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 33.

No: Repair the open circuit in harness between ECM connector and purge control solenoid valve 2 connector.
CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE 2 CONNECTOR.
Measure the resistance between the purge control solenoid valve 2 connector and engine ground.

Connector & terminal

(E52) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 34.

No: Repair the ground short circuit of harness between ECM connector and purge control solenoid valve 2 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. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE CONTROL MODULE (ECM) .
CHECK OF FUEL PUMP.
1. On the «Active Test» item, select «Fuel Pump Relay», and perform ON/OFF drive operation.
  NOTE: For detailed operation procedures, refer to the "Active Test". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 37.

No: Go to 36.
CHECK OF FUEL PUMP.
Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes: Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT .

No: Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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 38.
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. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

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

Yes: Go to 39.

No: Check the fuel pump and fuel delivery line. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION . Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL DELIVERY AND EVAPORATION LINES>INSPECTION .
CHECK FREEZE FRAME DATA.
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 "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE 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: Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

No: Check the high-pressure fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>HIGH PRESSURE FUEL PUMP>INSPECTION .
CHECK IGNITION SYSTEM.
Check the ignition system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 41.

No: Repair the ignition system. Refer to IGNITION (EXCEPT FOR STI)>GENERAL DESCRIPTION .
CHECK FREEZE FRAME DATA.
Compare with the reference value of «Load Value» described in "Engine Current Data Display" under "Subaru Select Monitor". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 43.

No: Go to 42.
CHECK FREEZE FRAME DATA.
Read the value of «A/F Sensor #1» using the Subaru Select Monitor.

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

Is the value of «A/F Sensor #1» less than 1?

Yes: Go to 47.

No: Go to 52.
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR.
Check the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 44.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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. 3:
  
  (B134) No. 28 - (B3) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 45.

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:

(B134) No. 28 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 46.

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. Compare with the reference value of «Load Value» described in "Engine Current Data Display" under "Subaru Select Monitor". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 47.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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. Select «Injection Quantity Control» in the «Active Test» item, and 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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 52.

No: Go to 48.
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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .

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

Yes: Replace the front oxygen (A/F) sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FRONT OXYGEN (A/F) SENSOR .

No: Go to 49.
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. 3 (+) - Engine ground (-):
Is the voltage 10 V or more?

Yes: Go to 50.

No: Repair the power supply line.
NOTE:
In this case, repair the following item:
- Open circuit in harness between A/F, oxygen sensor relay and front oxygen (A/F) sensor connector
- Poor contact of A/F, oxygen sensor relay connector
- Poor contact of coupling connector
- Malfunction of A/F, oxygen sensor 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. 15 - (E24) No. 1:
  
  (E158) No. 27 - (E24) No. 4:
  
  (E158) No. 39 - (E24) No. 5:
  
  (E159) No. 9 - (E24) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 51.

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. 15 - Engine ground:

(E158) No. 27 - Engine ground:

(E158) No. 39 - Engine ground:

(E159) No. 9 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 52.

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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 53.

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

Is the check result OK?

Yes: Go to 54.

No: Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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
  
  (E159) No. 27 - (E8) No. 1:
  
  (E158) No. 38 - (E8) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 55.

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. 38 - Engine ground:

(E159) No. 27 - 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. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 57.

No: Repair the ignition system. Refer to IGNITION (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 58.

No: Go to 60.
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. Refer to INTAKE (INDUCTION) (EXCEPT FOR STI)>GENERAL DESCRIPTION .

No: Go to 59.
CHECK AIR INTAKE SYSTEM.
Check the air intake system related parts.
- Brake booster: Refer to BRAKE>BRAKE BOOSTER>INSPECTION .
- Mass air flow and intake air temperature sensor: Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .
- PCV pipe: Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PCV PIPE>INSPECTION .
- PCV connector: Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PCV CONNECTOR>INSPECTION .
- PCV hose: Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PCV HOSE>INSPECTION .
- PCV hose assembly: Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PCV HOSE ASSEMBLY>INSPECTION .
- PCV valve: Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PCV VALVE>INSPECTION .
- Purge control solenoid valve 1 and purge control solenoid valve 2: Refer to EMISSION CONTROL (AUX. EMISSION CONTROL DEVICES) (EXCEPT FOR STI)>PURGE CONTROL SOLENOID VALVE>INSPECTION .
Are all of the air intake system related parts normal?

Yes: Go to 77.

No: Replace the parts if defective.
CHECK FREEZE FRAME DATA.
1. Using the Subaru Select Monitor, read the values of the followings: «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 "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
2. 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 77.

No: Diagnose the part that does not synchronize.
- Intake RH: Go to 61.
- Intake LH: Go to 65.
- Exhaust RH: Go to 69.
- Exhaust LH: Go to 73.
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 62.

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
  
  (E159) No. 7 - (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.
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 64.

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. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes: Replace the intake cam sprocket RH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

No: Replace the intake oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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 66.

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
  
  (E159) No. 15 - (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.
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 68.

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. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes: Replace the intake cam sprocket LH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

No: Replace the intake oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .
CHECK POWER SUPPLY TO THE EXHAUST OIL CONTROL SOLENOID RH.
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 power supply circuit.
CHECK HARNESS BETWEEN ECM AND EXHAUST 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 exhaust oil control solenoid RH.
  Connector & terminal
  
  (E159) No. 23 - (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.
CHECK HARNESS BETWEEN ECM 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 EXHAUST OIL CONTROL SOLENOID RH.
Check the exhaust oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes: Replace the exhaust cam sprocket RH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

No: Replace the exhaust oil control solenoid RH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .
CHECK POWER SUPPLY TO THE EXHAUST OIL CONTROL SOLENOID LH.
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 power supply circuit.
CHECK HARNESS BETWEEN ECM AND EXHAUST 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 exhaust oil control solenoid LH.
  Connector & terminal
  
  (E159) No. 31 - (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.
CHECK HARNESS BETWEEN ECM 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 EXHAUST OIL CONTROL SOLENOID LH.
Check the exhaust oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID>INSPECTION .

Is the check result OK?

Yes: Replace the exhaust cam sprocket LH. Refer to MECHANICAL (EXCEPT FOR STI)>CAM SPROCKET .

No: Replace the exhaust oil control solenoid LH. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>OIL CONTROL SOLENOID .
CHECK ENGINE COOLANT TEMPERATURE SENSOR.
Check the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>ENGINE COOLANT TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 78.

No: Replace the engine coolant temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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
  
  (E159) No. 27 - (E8) No. 1:
  
  (E158) No. 38 - (E8) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 79.

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. 38 - Engine ground:

(E159) No. 27 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 80.

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. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 81.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
CHECK MANIFOLD ABSOLUTE PRESSURE AND INTAKE AIR TEMPERATURE SENSOR.
Check the manifold absolute pressure and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MANIFOLD ABSOLUTE PRESSURE AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .

No: Check the manifold absolute pressure and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MANIFOLD ABSOLUTE PRESSURE AND INTAKE AIR TEMPERATURE SENSOR .
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. 12 - (E5) No. 1:
  
  #1 (E158) No. 11 - (E5) No. 2:
  
  #2 (E158) No. 24 - (E16) No. 1:
  
  #2 (E158) No. 23 - (E16) No. 2:
  
  #3 (E158) No. 36 - (E6) No. 1:
  
  #3 (E158) No. 35 - (E6) No. 2:
  
  #4 (E158) No. 48 - (E17) No. 1:
  
  #4 (E158) No. 47 - (E17) No. 2:
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. 12 - Engine ground:

#1 (E158) No. 11 - Engine ground:

#2 (E158) No. 24 - Engine ground:

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

#3 (E158) No. 36 - Engine ground:

#3 (E158) No. 35 - Engine ground:

#4 (E158) No. 48 - Engine ground:

#4 (E158) No. 47 - 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. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 85.

No: Repair the ignition system. Refer to IGNITION (EXCEPT FOR STI)>GENERAL DESCRIPTION .
CHECK FREEZE FRAME DATA.
Using the Subaru Select Monitor, read the values in «A/C Compressor Signal» and «Idle A/C load correct».

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

Does the value of «A/C Compressor Signal» indicate ON output, and does the value of «Idle A/C load correct» increase?

Yes: Check the air conditioner. Refer to HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON>INSPECTION . Refer to HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

No: Go to 86.
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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE FREEZE FRAME DATA .
2. Compare the value of «Electric Load Feedback Val» with that of «ISC Learning Value», which is described in "Engine Current Data Display". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .
NOTE: For detailed operation procedures, refer to "Current Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY CURRENT ENGINE DATA .

Is the value of «Electric Load Feedback Val» 20% or more of «ISC Learning Value»?

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

No: Go to 87.
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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 30 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. Refer to CONTINUOUSLY VARIABLE TRANSMISSION (TR690)>GENERAL DESCRIPTION .

No: Go to 88.
CHECK DTC.
Read the engine DTC using the Subaru Select Monitor or general scan tool. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>READ DIAGNOSTIC TROUBLE CODE (DTC) .

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

Yes: Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer 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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 90.

No: Go to 94.
CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR.
Check the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR>INSPECTION .

Is the check result OK?

Yes: Go to 91.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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. 3:
  
  (B134) No. 28 - (B3) No. 2:
Is the resistance less than 1 Ω?

Yes: Go to 92.

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:

(B134) No. 28 - Engine ground:

Is the resistance 1 MΩ or more?

Yes: Go to 93.

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. Compare with the reference value of «Load Value» described in "Engine Current Data Display" under "Subaru Select Monitor". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 94.

No: Replace the mass air flow and intake air temperature sensor. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
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. 12 - (E5) No. 1:
  
  #1 (E158) No. 11 - (E5) No. 2:
  
  #2 (E158) No. 24 - (E16) No. 1:
  
  #2 (E158) No. 23 - (E16) No. 2:
  
  #3 (E158) No. 36 - (E6) No. 1:
  
  #3 (E158) No. 35 - (E6) No. 2:
  
  #4 (E158) No. 48 - (E17) No. 1:
  
  #4 (E158) No. 47 - (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.
CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR.
Measure the resistance between the ECM connector and engine ground.

Connector & terminal

#1 (E158) No. 12 - Engine ground:

#1 (E158) No. 11 - Engine ground:

#2 (E158) No. 24 - Engine ground:

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

#3 (E158) No. 36 - Engine ground:

#3 (E158) No. 35 - Engine ground:

#4 (E158) No. 48 - Engine ground:

#4 (E158) No. 47 - 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.
CHECK IGNITION SYSTEM.
Check the ignition system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE>IGNITION CONTROL SYSTEM .

Is the check result OK?

Yes: Go to 97.

No: Repair the ignition system. Refer to IGNITION (EXCEPT FOR STI)>GENERAL DESCRIPTION .
CHECK OF FUEL PUMP.
1. On the «Active Test» item, select «Fuel Pump Relay», and perform ON/OFF drive operation.
  NOTE: For detailed operation procedures, refer to the "Active Test". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>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 99.

No: Go to 98.
CHECK OF FUEL PUMP.
Check fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION .

Is the check result OK?

Yes: Check fuel pump system. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P0230 FUEL PUMP PRIMARY CIRCUIT .

No: Replace the fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>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 100.
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. Refer to MECHANICAL (EXCEPT FOR STI)>FUEL PRESSURE>INSPECTION .

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

Yes: Go to 101.

No: Check the fuel pump and fuel delivery line. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL PUMP>INSPECTION . Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>FUEL DELIVERY AND EVAPORATION LINES>INSPECTION .
CHECK FREEZE FRAME DATA.
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 "Freeze Frame Data Display For Engine". Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>SUBARU SELECT MONITOR>OPERATION>DISPLAY OF ENGINE 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 102.

No: Check the high-pressure fuel pump. Refer to FUEL INJECTION (FUEL SYSTEMS) (EXCEPT FOR STI)>HIGH PRESSURE FUEL PUMP>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. Refer to MECHANICAL (EXCEPT FOR STI)>SYMPTOMS AND CAUSES>INSPECTION .

No: Perform the Clear Memory Mode to complete. Refer to ENGINE (DIAGNOSTICS) (EXCEPT FOR STI)>CLEAR MEMORY MODE .