PR25DD engine

1. Start engine and warm it up to the normal operating temperature.
2. Clear the air fuel ratio initial learning. Refer to Work Procedure .
3. 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 Diagnosis Procedure .

NO

GO TO 2.

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

   HO2S2		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   E78	4	F90	76	Existed

5. 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.

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

   HO2S2		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   E78	3	F90	77	Existed

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

   HO2S2		--	Continuity
   Connector	Terminal
   E78	3	Ground	Not existed

   ECM		--	Continuity
   Connector	Terminal
   F90	77	Ground	Not existed

3. 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.

Refer to Component Inspection .

Is the inspection result normal?

YES

INSPECTION END

NO

GO TO 5.

Replace heated oxygen sensor 2. Refer to EXHAUST SYSTEM : Exploded View (AWD MODELS) or EXHAUST SYSTEM : Exploded View (FWD MODELS).

INSPECTION END