Diagnosis Procedure
- PERFORM AIR FUEL RATIO INITIAL LEARNING
- Start engine and warm it up to the normal operating temperature.
- Clear the air fuel ratio initial learning. Refer to Work Procedure .
- Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 detected? Is it difficult to start engine?
YES
Perform trouble diagnosis for DTC P0171. Refer to Diagnosis Procedure .
NO
GO TO 2.
- CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
- Check the continuity between HO2S2 harness connector and ECM harness connector.
HO2S2
ECM
Continuity
Connector
Terminal
Connector
Terminal
E39
1
F52
76
Existed
- Also check harness for short to ground and short to power.
Is the inspection result normal?
YES
GO TO 3.
NO
Repair or replace malfunctioning part.
- CHECK HO2S2 INPUT SIGNAL CIRCUIT
- Check the continuity between HO2S2 harness connector and ECM harness connector.
HO2S2
ECM
Continuity
Connector
Terminal
Connector
Terminal
E39
2
F52
77
Existed
- Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and ground.
HO2S2
--
Continuity
Connector
Terminal
E39
2
Ground
Not existed
ECM
--
Continuity
Connector
Terminal
F52
77
Ground
Not existed
- Also check harness for short to ground and short to power.
Is the inspection result normal?
YES
GO TO 4.
NO
Repair or replace malfunctioning part.
- Check the continuity between HO2S2 harness connector and ECM harness connector.
- CHECK HEATED OXYGEN SENSOR 2
Refer to Component Inspection .
Is the inspection result normal?
YES
INSPECTION END
NO
GO TO 5.
- REPLACE HEATED OXYGEN SENSOR 2
Replace heated oxygen sensor 2. Refer to Exploded View .
CAUTION:- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads.
INSPECTION END