DTC Diagnosis Procedure

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

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Is exhaust gas leakage detected?

YES

Repair or replace malfunctioning part.

NO

GO TO 2.

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

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.

   A/F sensor 1		ECM		Continuity
   Connector	Terminal	Connector	Terminal
   F2	1	F19	79	Existed
   	2		74

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

   A/F sensor 1		--	Continuity
   Connector	Terminal
   F2	1	Ground	Not existed
   	2

   ECM		--	Continuity
   Connector	Terminal
   F19	79	Ground	Not existed
   	74

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

Is the inspection result normal?

YES

GO TO 4.

NO

Repair or replace malfunctioning part.

If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

GO TO 5.

1. Clear the mixture ratio self-learning value. Refer to Description.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3, 500 and 4, 000 rpm for 1 minute under no load.
6. Let engine idle for 1 minute.
7. Keep engine speed between 2, 500 and 3, 000 rpm for 20 minutes.
8. Check DTC.

Is DTC detected?

YES

Replace A/F sensor. Refer to EXHAUST MANIFOLD : Exploded View .

NO

GO TO 6.

Check fuel pressure. Refer to Work Procedure .

Is the inspection result normal?

YES

GO TO 8.

NO

GO TO 7.

Check fuel hoses and fuel tubes for clogging.

Is the inspection result normal?

YES

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

NO

Repair or replace malfunctioning part.

With CONSULT

1. Install all removed parts.
2. Start the engine and warm it up to normal operating temperature.
3. Check "MASS AIR FLOW SENSOR (Hz)" in "DATA MONITOR" mode of "ENGINE" using CONSULT.

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

   *: Check for linear frequency rise in response to increase of engine speed.

Without CONSULT

1. Install all removed parts.
2. Start the engine and warm it up to normal operating temperature.
3. Check the frequency between ECM harness connector terminals under the following conditions.

   ECM			Condition	Frequency
   Connector	+	-
   	Terminal
   F18	37	42	Ignition switch ON (Engine stopped.)	Approx. 3, 700 Hz
   			Idle (Engine is warmed-up to normal operating temperature.)	Approx. 5, 500 Hz
   			Idle to about 4, 000 rpm	5, 500 Hz -> 7, 000 Hz*

   *: Check for linear frequency rise in response to increase of engine speed.

Is the inspection result normal?

YES

GO TO 9.

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

Without CONSULT

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

   Clicking sound should be heard.

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Is the inspection result normal?

YES

INSPECTION END

NO

Perform trouble diagnosis for fuel injector and circuit, refer to Diagnosis Procedure .