Diagnostic 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 " for DTC P0171, P0174.

OK or NG 

OK: GO TO 4.

NG: Go to "DIAGNOSTIC PROCEDURE " for DTC P0171, P0174.

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