Diagnostic Test

1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
   Fig 1: Inspecting For Exhaust Gas Leaks

   Courtesy of NISSAN NORTH AMERICA, INC.

Is exhaust gas leak detected?

YES 

Repair or replace error-detected parts.

NO 

GO TO STEP 2  .

1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.

Intake air leak detected?

YES 

Repair or replace error-detected parts.

NO 

GO TO STEP 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.

   +		-		Continuity
   A/F sensor 1		ECM
   Connector	Terminal	Connector	Terminal
   F72	1	F24	79	Existed
   	2		74

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

   +		-	Continuity
   A/F sensor 1
   Connector	Terminal
   F72	1	Ground	Not existed
   	2

   +		-	Continuity
   ECM
   Connector	Terminal
   F24	79	Ground	Not existed
   	74

6. Also check harness for short to power.

Is the inspection result normal?

YES 

GO TO STEP 4  .

NO 

Repair or replace error-detected parts.

Check fuel pressure. Refer to WORK PROCEDURE .

Is the inspection result normal?

YES 

GO TO STEP 6  .

NO 

GO TO STEP 5  .

Check fuel hoses and fuel tubes for clogging. Refer to EXPLODED VIEW .

Is the inspection result normal?

YES 

Replace "fuel filter and fuel pump assembly". Refer to EXPLODED VIEW (2WD) or EXPLODED VIEW (AWD).

NO 

Repair or replace error-detected parts.

With CONSULT

1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and warm it up to normal operating temperature.
4. Connect CONSULT and select "DATA MONITOR" mode.
5. Select "MASS AIR FLOW SENSOR (Hz)" and check the indication.

   Monitor item	Condition	Indication (Hz)
   MASS AIR FLOW SENSOR (Hz)	Ignition switch ON (Engine stopped.)	Approx. 3, 700 Hz
   	Idle (Engine is warmed-up to normal operating temperature.)	5, 100 - 5, 500 Hz
   	2, 500 RPM (Engine is warmed-up to normal operating temperature.)	6, 100 - 6, 500 Hz
   	Idle to about 4, 000 RPM	5, 100 - 5, 500 to Approx. 7, 000 Hz*

   * : Check for linear frequency rise in response to engine being increased to about 4, 000 RPM.

Without CONSULT

1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and warm it up to normal operating temperature.
4. Check the frequency between ECM harness connector terminals under the following conditions.

   ECM			Condition	Frequency (Hz)
   Connector	+	-
   	Terminal
   F23	37	42	Ignition switch ON (Engine stopped.)	Approx. 3, 700 Hz
   			Idle (Engine is warmed-up to normal operating temperature.)	5, 100 - 5, 500 Hz
   			2, 500 RPM (Engine is warmed-up to normal operating temperature.)	6, 100 - 6, 500 Hz
   			Idle to about 4, 000 RPM	5, 100 - 5, 500 to Approx. 7, 000 Hz*

   * : Check for linear frequency rise in response to engine being increased to about 4, 000 RPM.

Is the inspection result normal?

YES 

GO TO STEP 7  .

NO 

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

With CONSULT

1. Start engine.
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode of "ENGINE" using CONSULT.
3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT

1. Let engine idle.
2. Listen to each fuel injector operating sound.
   Fig 2: Checking Fuel Injector Operating Sound

   Courtesy of NISSAN NORTH AMERICA, INC.

   Clicking noise should be heard.

Is the inspection result normal?

YES 

Check intermittent incident. Refer to INTERMITTENT INCIDENT .

NO 

Perform trouble diagnosis for "FUEL INJECTOR", refer to COMPONENT FUNCTION CHECK .