Diagnosis Procedure

Perform , "IDLE AIR VOLUME LEARNING ".

Is Idle Air Volume Learning carried out successfully? 

Yes or No 

Yes: GO TO 2.

No: Follow the instruction of Idle Air Volume Learning.

Check for the cause of intake air volume lacking. Refer to the following.

• Crushed intake air passage
• Intake air passage clogging

OK or NG 

OK: GO TO 3.

NG: Repair or replace malfunctioning part

Perform , "DTC CONFIRMATION PROCEDURE " in DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION.

OK or NG 

OK: GO TO 4.

NG: Go to , "DIAGNOSIS PROCEDURE ".

With CONSULT-III 

1. Turn ignition switch ON.
2. Select "SELF-DIAG RESULTS" mode with CONSULT-III.
3. Touch "ERASE".
4. Perform DTC Confirmation Procedure. 

   See , "DTC CONFIRMATION PROCEDURE ".

5. Is the 1st trip DTC P1421 displayed again?

With GST 

1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform DTC Confirmation Procedure. 

   See , "DTC CONFIRMATION PROCEDURE ".

4. Is the 1st trip DTC P1421 displayed again?

Yes or No 

Yes: GO TO 5.

No: INSPECTION END 

1. Replace ECM.
2. Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs.

   Refer to , "ECM RE-COMMUNICATING FUNCTION ".

3. Perform , "VIN REGISTRATION ".
4. Perform , "ACCELERATOR PEDAL RELEASED POSITION LEARNING ".
5. Perform , "THROTTLE VALVE CLOSED POSITION LEARNING ".
6. Perform , "IDLE AIR VOLUME LEARNING ".

INSPECTION END