Diagnosis Procedure

If DTC P0102 or P0103 is displayed with DTC P0643, first perform the confirmation procedure (trouble diagnosis) for DTC P0643.

Is DTC P0643 detected?

YES

Perform diagnosis for P0643. Refer to DTC Description .

NO

GO TO 2.

Confirm the detected DTC.

Which DTC is detected?

P0102

GO TO 3.

P0103

GO TO 4.

Check the following for connection.

• Air duct
• Vacuum hoses
• Intake air passage between air duct to intake manifold

Is the inspection result normal?

YES

GO TO 4.

NO

Reconnect the parts.

1. Disconnect mass air flow sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between mass air flow sensor harness connector and ground.

   +		-	Voltage (Approx.)
   Mass air flow sensor
   Connector	Terminal
   E64	1	Ground	5 V

Is the inspection result normal?

YES

GO TO 6.

NO

GO TO 5.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between mass air flow sensor harness connector and ECM harness connector.

   Mass air flow sensor		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   E64	1	F78	37	Existed

4. Also check harness for short to power and short to ground.

Is the inspection result normal?

YES

Perform the trouble diagnosis for ECM power supply circuit. Refer to Diagnosis Procedure .

NO

Repair or replace error-detected parts.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between mass air flow sensor harness connector and ECM harness connector.

   Mass air flow sensor		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   E64	3	F78	42	Existed

4. Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 7.

NO

Repair open circuit, short to ground or short to power in harness or connectors.

1. Check the continuity between ECM harness connector and ground.

   ECM		--	Continuity
   Connector	Terminal
   F78	2	Ground	Existed
   	7
   F79	87
   	88
   	95
   E32	199
   	201
   	204

2. Also check harness for short to power.

Is the inspection result normal?

YES

GO TO 8.

NO

Repair or replace error-detected parts.

1. Check the continuity between mass air flow sensor harness connector and ECM harness connector.

   Mass air flow sensor		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   E64	2	F78	41	Existed

2. Also check harness for short to power and short to ground.

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 (Mass Air Flow Sensor) .

Is the inspection result normal?

YES

INSPECTION END

NO

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