Diagnostic Procedure
- CHECK GROUND CONNECTIONS
- Turn ignition switch OFF.
- Loosen and retighten three ground screws on the body. Refer to , "GROUND INSPECTION ".
OK or NG
OK : GO TO 2.
NG : Repair or replace ground connections.
- CLEAR THE SELF-LEARNING DATA
With CONSULT-II
- Start engine and warm it up to normal operating temperature.
- Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-II.
- Clear the self-learning control coefficient by touching "CLEAR".
- Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Without CONSULT-II
- Start engine and warm it up to normal operating temperature.
- Turn ignition switch OFF.
- Disconnect mass air flow sensor harness connector.
- Restart and let it idle for at least 5 seconds.
- Stop engine and reconnect mass air flow sensor harness connector.
- Make sure DTC P0102 is displayed.
- Erase the DTC memory. Refer to , "HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION ".
- Make sure DTC P0000 is displayed.
- Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Yes or No
Yes : Perform trouble diagnosis for DTC P0171, P0174. Refer to DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION .
No : GO TO 3.
- CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Disconnect heated oxygen sensor 2 harness connector.
- Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to ground and short to power.
OK or NG
OK : GO TO 4.
NG : Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to WIRING DIAGRAM .DTC CHART
DTC Terminals Bank ECM Sensor P0137 74 1 1 P0157 55 1 2 Continuity should exist.
- Check harness continuity between the following terminals and ground. Refer to WIRING DIAGRAM .DTC CHART
DTC Terminals Bank ECM Sensor P0137 74 1 1 P0157 55 1 2 Continuity should not exist.
- Also check harness for short to power.
OK or NG
OK : GO TO 5.
NG : Repair open circuit or short to ground or short to power in harness or connectors.
- Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to WIRING DIAGRAM .
- CHECK HEATED OXYGEN SENSOR 2
Refer to , "COMPONENT INSPECTION ".
OK or NG
OK : GO TO 6.
NG : Replace malfunctioning heated oxygen sensor 2.
- CHECK INTERMITTENT INCIDENT
Refer to , "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
: INSPECTION END