DTC Diagnosis Procedure

1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before three way catalyst (manifold).

   Courtesy of NISSAN NORTH AMERICA, INC.

Is exhaust gas leakage detected?

YES

Repair or replace malfunctioning part.

NO

GO TO 2.

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

Is intake air leakage detected?

YES

Repair or replace malfunctioning part.

NO

GO TO 3.

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

   DTC	A/F sensor 1			ECM		Continuity
   	Bank	Connector	Terminal	Connector	Terminal
   P0172	1	F89* 1 F133* 2	1	F92	79	Existed
   			2		74
   P0175	2	F90* 1 F134* 2	1	F92	69
   			2		70

   *1: For Mexico

   *2: Except for Mexico

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

   DTC	A/F sensor 1			Ground	Continuity
   	Bank	Connector	Terminal
   P0172	1	F89* 1 F133* 2	1	Ground	Not Existed
   			2
   P0175	2	F90* 1 F134* 2	1
   			2

   *1: For Mexico

   *2: Except for Mexico

   DTC	ECM			Ground	Continuity
   	Bank	Connector	Terminal
   P0172	1	F92	79	Ground	Not Existed
   			74
   P0175	2	F92	69
   			70

6. 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.

Check fuel pressure. Refer to Work Procedure .

Is the inspection result normal?

YES

GO TO 5.

NO

Replace fuel filter and fuel pump assembly". Refer to FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY : Removal & Installation .

WITH CONSULT

1. Install all removed parts.
2. Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT.

   For specification, Refer to MASS AIR FLOW SENSOR : Service Data .

WITH GST

1. Install all removed parts.
2. Check mass air flow sensor signal in "Service $01" with GST.

   For specification, Refer to MASS AIR FLOW SENSOR : Service Data .

Is the measurement value within the specification?

YES

GO TO 6.

NO

Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to DTC Diagnosis Procedure .

WITH CONSULT

1. Start engine.
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT.
3. Check that each circuit produces a momentary engine speed drop.

WITHOUT CONSULT

1. Start engine and let it idle.
2. Listen to each fuel injector operating sound.

   Courtesy of NISSAN NORTH AMERICA, INC.

   Clicking sound should be heard.

Is the inspection result normal?

YES

GO TO 7.

NO

Perform trouble diagnosis for fuel injector, Refer to Diagnosis Procedure .

Refer to Inspection .

Is the inspection result normal?

YES

Replace fuel injector. Refer to FUEL INJECTOR AND FUEL TUBE : Removal & Installation .

NO

Repair or replace malfunctioning part.