Powertrain OBD System Check

IMPORTANT: Understanding the table and using it correctly will reduce diagnosis time and prevent the unnecessary replacement of parts.

The Powertrain OBD System Check is an organized approach for identifying a problem. After the visual inspection is complete, the Powertrain OBD System Check should be performed. This Powertrain System Check will provide direction for diagnosis of the following items:
^ A faulty or inoperative PCM
^ No serial data
^ Malfunction Indicator Lamp (MIL) inoperative
^ PCM DTCs
^ Fuel system rich or lean
^ Customer complaint driveability symptoms

The Powertrain OBD System Check is designed as a master table for driveability and emissions system diagnosis. The system check should always be used as the starting point for all engine control system diagnosis.