Diagnosis Procedure

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
   E35	4	F52	97	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
   E35	3	F52	92	Existed

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

   HO2S2		-	Continuity
   Connector	Terminal
   E35	3	Ground	Not existed

   ECM		-	Continuity
   Connector	Terminal
   F52	92	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 REMOVAL AND INSTALLATION .

>>

INSPECTION END