DTC Diagnosis Procedure

1. Turn ignition switch OFF.
2. Check ground connection E191. Refer to Ground Inspection Inspection .

Is the inspection result normal?

YES

GO TO 2.

NO

Repair or replace ground connection.

1. Clear the mixture ratio self-learning value. Refer to Work Procedure .
2. 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 DTC Description .

NO

GO TO 3.

1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between HO2S2 harness connector and ECM harness connector.

   HO2S2			ECM		Continuity
   Bank	Connector	Terminal	Connector	Terminal
   1	F125	4	F143	81	Existed

5. Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 4.

NO

Repair open circuit, short to ground or short to power in harness or connectors.

1. Check the continuity between HO2S2 harness connector and ECM harness connector.

   HO2S2			ECM		Continuity
   Bank	Connector	Terminal	Connector	Terminal
   1	F125	3	F143	49	Existed

2. Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and ground.

   HO2S2			--	Continuity
   Bank	Connector	Terminal
   1	F125	3	Ground	Not existed

   HO2S2			--	Continuity
   Bank	Connector	Terminal
   1	F143	49	Ground	Not existed

3. Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 5.

NO

Repair open circuit, short to ground or short to power in harness or connectors.

Refer to Component Inspection .

Is the inspection result normal?

YES

INSPECTION END

NO

Replace malfunctioning heated oxygen sensor 2. Refer to CATALYST : Exploded View .