ECM - CEL ON/DTC 32 Under Heavy Load

File In Section: 6E - Engine Fuel & Emission

Bulletin No.: 57-65-09

Date: December, 1995

Subject:
Diagnostic Trouble Code 32 While Under Heavy Load (Install New MEM-CAL)

Models:
1994-95 Chevrolet and GMC Truck C/K, G, P Models with 7.4L Engine (VIN N - RPO L19)

Condition
Some owners may comment of a CEL while under a heavy load such as towing. The ECM will have a stored DTC 32.

Cause
Under certain driving conditions, usually while towing, the EGR is commanded to cycle oft and on rapidly. This can cause the EGR to appear unresponsive to ECM.








Correction
The calibration has been changed to become more robust with respect to the conditions causing the EGR to rapidly cycle. Install the appropriate MEM-CAL from the charts.

Parts are currently available from GMSPO.