Engine Controls - Tests W/codes: Other Subaru Outback BG

HARD FAILURES

Hard failures cause Malfunction Indicator Light (MIL) to illuminate and remain on until problem is repaired. If MIL comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using Diagnostic Trouble Code (DTC) charts. If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, commonly known as limp-in mode, vehicle runs but driveability will not be optimum.

INTERMITTENT FAILURES

Intermittent failures may cause MIL to flicker or illuminate then go out after intermittent fault goes away. However, a corresponding DTC will be retained in ECM memory. If related fault does not reoccur within a certain time frame, related DTC will be erased from ECM memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in appropriate TESTS W/O CODES article.

CIRCUIT TESTS

Note. Subaru Select Monitor (SSM) or an OBD-II scan tool must be used to perform self-diagnostic tests. Follow scan tool manufacturer's instructions.

Note. Values given in tests are based on the use of SSM scan tool. Manufacturer information did not include values for OBD-II scan tool.

Condition

Following conditions must be present to set DTC

1. Uneven idle
2. Engine stalls
3. Poor driveability

"b" - Group Of Cylinders No. 1 & 2

Check following items for cylinders No. 1 and 2

1. Spark plugs
2. Fuel injectors
3. Igniters, ignition coils, etc.

"c" - Group Of Cylinders No. 3 & 4

Check following items for cylinders No. 3 and 4

1. Spark plugs
2. Fuel injectors
3. Igniters, ignition coils, etc.

"d" - Group Of Cylinders No. 1 & 3

Check following items for cylinders No. 1 and 3

1. Spark plugs
2. Fuel injectors
3. Skipped/jumped timing belt

"e" - Group Of Cylinders No. 2 & 4

Check following items for cylinders No. 2 and 4

1. Spark plugs
2. Fuel injectors
3. Skipped/jumper timing belt teeth

"f" - Cylinder At Random

If engine idle is not rough, go to DTC P0170 and retest. If engine idle is rough, refer to already noted minimum EGR pressure (function mode F42). If EGR pressure is less than one kPa, clean EGR valve. If EGR pressure value is greater than one kPa, diagnose using DTC P0170 and retest.

Note. Remove and blow away exhaust deposits. Ensure valve operates smoothly and valve seat area is completely clean. Replace EGR valve if required.

"a"

Conduct CLEAR MEMORY and INSPECTION MODES.

"b"

Connect SSM to DLC.

Start and warm engine until radiator fan completes one cycle (all accessories OFF).

Turn SSM on and select function mode FA4.

Drive vehicle at 52-58 MPH until LED No. 2 is illuminated.

Note. Keep throttle valve opening steady. Diagnosis will be interrupted if throttle opening varies. Diagnosis starts in 190 seconds after starting engine and requires 4 seconds to run. Transmission should be in Drive range for diagnosis.

"f"

On SSM, select function mode FB0. Confirm "No Trouble" indication on SSM.

SUMMARY

If no hard fault codes are present, driveability symptoms exist or intermittent codes exist, proceed to INTRODUCTION .

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with self-diagnostics. If no fault codes are present after entering self-diagnostics, proceed to appropriate TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.