Diagnostic Test

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 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.

Is 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.

   DTC	A/F sensor 1			ECM		Continuity
   	Bank	Connector	Terminal	Connector	Terminal
   P0171	1	F72	3	F79	102	Existed
   			4		101
   P0174	2	F73	3		111
   			4		107

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

   DTC	A/F sensor 1			-	Continuity
   	Bank	Connector	Terminal
   P0171	1	F72	3	Ground	Not existed
   			4
   P0174	2	F73	3
   			4

   DTC	ECM			-	Continuity
   	Bank	Connector	Terminal
   P0171	1	F79	101	Ground	Not existed
   			102
   P0174	2		107
   			111

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.

1. Release fuel pressure to zero. Refer to WORK PROCEDURE .
2. Install fuel pressure gauge and 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.

Is the inspection result normal?

YES 

Replace "fuel level sensor, fuel filter and fuel pump assembly". Refer to REMOVAL AND INSTALLATION .

NO 

Repair or replace error-detected parts.

With CONSULT 

1. Install all removed parts.
2. Check "MASS AIR FLOW SENSOR (Hz)" in "Data Monitor" mode of "ENGINE".

   For specification, refer to MASS AIR FLOW SENSOR .

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 .

Is the measurement value within the specification?

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 DIAGNOSIS PROCEDURE .

With CONSULT 

1. Start engine.
2. Perform "POWER BALANCE" in "Active Test" mode of "ENGINE".
3. Make sure 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.

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   Clicking sound should be heard.

Is the inspection result normal?

YES 

INSPECTION END

NO 

Perform trouble diagnosis for FUEL INJECTOR, refer to DIAGNOSIS PROCEDURE .