Engine CONTROLSDIAGNOSTIC System Check: Description

WARNING: This page is about a different car, the 2001 GMC Safari and 2001 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.

Engine controlsdiagnostic system check is an organized approach to identifying a condition that is created by a malfunction in powertrain control system. Engine controlsdiagnostic system check must be starting point for any driveability concern. Engine controlsdiagnostic system check directs service technician to next logical step in order to diagnose concern. Understanding and correctly using diagnostic procedure reduces diagnostic time, and prevents replacement of good parts.

If Powertrain Control Module (PCM) stores multiple PCM DTCs, diagnose DTCs in following order: Component level DTCs, such as sensor DTCs, solenoid DTCs, and relay DTCs. Diagnose multiple DTCs within this category in numerical order. Begin with lowest numbered DTC, unless diagnostic procedure directs you otherwise. System level DTCs, for example, misfire DTCs, fuel trim DTCs, and catalyst DTCs.