Test Description

Powertrain Control Module (PCM) diagnostic system check is an organized approach to identifying a condition that is created by a malfunction in powertrain control system. Diagnostic system check must be the starting point for any driveability concern. Diagnostic system check directs the service technician to the next logical step in order to diagnose the concern. Understanding and correctly using the diagnostic table reduces diagnostic time, and prevents replacement of good parts.

If PCM stores multiple powertrain DTCs, diagnose the DTCs in the following order:

• Component level DTCs, such as sensor DTCs, solenoid DTCs, and relay DTCs. Diagnose the multiple DTCs within this category in numerical order. Begin with the lowest numbered DTC, unless the diagnostic table directs you otherwise.
• System level DTCs, for example, misfire DTCs, fuel trim DTCs, and catalyst DTCs.