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.

Loosen and retighten the A/F sensor 1. Refer to TURBOCHARGER : Exploded View .

GO TO 3.

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst 1.

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Is exhaust gas leak detected?

YES

Repair or replace.

NO

GO TO 4.

Listen for an intake air leak after the mass air flow sensor.

Is intake air leak detected?

YES

Repair or replace.

NO

GO TO 5.

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 P0174 or P0175 detected? Is it difficult to start engine?

YES

Perform trouble diagnosis for DTC P0174 or P0175. Refer to DTC Description .orRefer to DTC Description .

NO

GO TO 6.

1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check the voltage between A/F sensor 1 harness connector and ground.

   +			-	Voltage
   A/F sensor 1
   Bank	Connector	Terminal
   2	F134	1	Ground	Battery voltage

Is the inspection result normal?

YES

GO TO 8.

NO

GO TO 7.

Check the following.

• Harness connectors E10, F12
• IPDM E/R harness connector E123
• 15A fuse (No. 48)
• Harness for open or short between A/F sensor 1 and fuse

Repair or replace harness or connectors.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

   A/F sensor 1			ECM		Continuity
   Bank	Connector	Terminal	Connector	Terminal
   2	F134	3	F142	106	Existed
   		4		105

4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.

   A/F sensor 1			--	Continuity
   Bank	Connector	Terminal
   2	F134	3	Ground	Not existed
   		4

   ECM			--	Continuity
   Bank	Connector	Terminal
   2	F142	106	Ground	Not existed
   		105

5. Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 9.

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

GO TO 10.

NO

Replace malfunctioning air fuel ratio (A/F) sensor 1. Refer to TURBOCHARGER : Exploded View .

Check both mass air flow sensor (bank 1 and bank 2).

Refer to Component Inspection .

Is the inspection result normal?

YES

GO TO 11.

NO

Replace malfunctioning mass air flow sensor. Refer to AIR CLEANER AND AIR DUCT : Exploded View .

Refer to POSITIVE CRANKCASE VENTILATION : Periodic Maintenance Operation .

Is the inspection result normal?

YES

Replace malfunctioning air fuel ratio (A/F) sensor 1. Refer to TURBOCHARGER : Exploded View .

NO

Repair or replace PCV valve. Refer to IGNITION COIL, SPARK PLUG AND ROCKER COVER : Exploded View .