Diagnostic Procedure
- RETIGHTEN GROUND SCREWS
- Turn ignition switch OFF.
- Loosen and retighten engine ground screws.
- GO TO 2.
- 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 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, and restart and run engine for at least 3 seconds at idle speed.
- 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 detected?
Is it difficult to start engine?
Yes or No
- Yes: Perform trouble diagnosis for DTC P0171. Refer to DTC P0171 FUEL INJECTION SYSTEM FUNCTION .
- No: GO TO 3.
- CHECK INPUT SIGNAL CIRCUIT
- Disconnect heated oxygen sensor 2 harness connector and ECM harness connector.
- Check harness continuity between ECM terminal 56 and HO2S2 terminal 1.
Refer to WIRING DIAGRAM .
Continuity should exist.
- Check harness continuity between ECM terminal 56 or HO2S2 terminal 1 and ground.
Refer to WIRING DIAGRAM .
Continuity should not exist.
- Also check harness for short to ground and short to power.
OK or NG
- OK: GO TO 5.
- NG: GO TO 4.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M58, F28
- Harness for open or short between ECM and heated oxygen sensor 2
- Repair open circuit or short to ground or short to power in harness or connectors.
- CHECK GROUND CIRCUIT
- Check harness continuity between heated oxygen sensor 2 terminal 4 and engine ground. Refer to WIRING DIAGRAM .
Continuity should exist.
- Also check harness for short to power.
OK or NG
- OK: GO TO 7.
- NG: GO TO 6.
- Check harness continuity between heated oxygen sensor 2 terminal 4 and engine ground. Refer to WIRING DIAGRAM .
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors M58, F28
- Harness for open or short between heated oxygen sensor 2 and engine ground
- Repair open circuit or short to power in harness or connectors.
- CHECK HEATED OXYGEN SENSOR 2
Refer to "COMPONENT INSPECTION ".
OK or NG
- OK: GO TO 8.
- NG: Replace heated oxygen sensor 2.
- CHECK INTERMITTENT INCIDENT
Perform "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
- : INSPECTION END.