Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, 2002 Chevrolet RV Cutaway, and 2002 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

The injector balance test on the scan tool should be used to confirm fault cylinder problems. The scan tool will cutout the specific cylinder requested. If a cylinder balance fault has been detected and the engine has been running for a long time, the PCM may try to increase or decrease fuel in the other cylinders in order to compensate for a rough idle. This can cause multiple cylinder balance DTCs to set. Malfunctioning nozzles are the most likely cause of cylinder balance DTCs.

If multiple cylinder balance DTCs are set and no problem is found, check for:

A pinched or restricted fuel feed lines between the fuel tank and the fuel injection pump.
A restricted fuel filter.