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Engine Controls - Hard Cranking, Updated ECM

Classification: EC95-015

Reference: NTB95-090

Date: September 20, 1995

1995 MAXIMA HARD CRANKING

APPLIED VEHICLE:
1995 Maxima (A32)

APPLIED VIN:

Prior to JN1CA21D*ST635158
Prior to JN1CA21D*ST082594

APPLIED DATE:
Vehicles built prior to January 10, 1995

SERVICE INFORMATION

If a customer complains of a hard/slow cranking condition which occurs when the engine is being restarted within one second of the first start attempt, the ECM may not have time to accurately determine Top Dead Center on # 1 cylinder. The result is extremely advanced spark timing and a hard/slow cranking condition may occur. A countermeasure (C/M) ECM is now available with revised control logic to reduce the chance that this incident will occur. Vehicles built after January 10, 1995 have this C/M ECM installed during production.

SERVICE PROCEDURE

The most important part of this diagnosis is to interview the customer to determine if his/her complaint can be effectively resolved by replacing the ECM. The best way to verify this is by observing the customer's starting procedure while the incident is occurring.

Not all hard cranking/starting incidents can be resolved by replacing the ECM. By using the following diagnostic procedures, a technician can determine if a C/M ECM is required to resolve a hard cranking incident.








This table can be used to determine that proper repair does require a C/M ECM:





This table can be used to determine that proper repair DOES NOT require a C/M ECM:





Parts/Claim Information