1.PERFORM IDLE AIR VOLUME LEARNING Perform Special Repair Requirement (GT-R certified NISSAN dealer). Is Idle Air Volume Learning carried out successfully? YES>>GO TO 2. NO>>Follow the instruction of Idle Air Volume Learning.
2.CHECK Intake system
Check for the cause of intake air volume lacking. Refer to the following.

- Crushed intake air passage
- Intake air passage clogging

Is the inspection result normal?
YES>>GO TO 3.
NO>>Repair or replace malfunctioning part
3.CHECK FUEL INJECTION SYSTEM FUNCTION
Perform DTC Confirmation Procedure for DTC P0171, P0174. Refer to DTC Logic (GT-R certified NISSAN dealer).
Is the inspection result normal?
YES>>GO TO 4.
NO>>Go to Diagnosis Procedure (GT-R certified NISSAN dealer) for DTC P0171, P0174.
4.PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC Confirmation Procedure.See DTC Logic (GT-R certified NISSAN dealer).

Is the 1st trip DTC P1421 displayed again?
YES>>GO TO 5.
NO>>INSPECTION END
5.REPLACE ECM

1. Replace ECM.
2. Go to Special Repair Requirement (GT-R certified NISSAN dealer).

>>INSPECTION END