Initial Inspection and Diagnostic Overview

PCM DATA LINE
1. If all components are not accessible with a scan tool, check for an open in CKT 461 between DLC terminal "M" and S215.

2. If a single component is not accessible with a scan tool, check for an open in CKT 461 between S215 and the component. If the wire is OK, refer to Engine Control Module for Engine Control Module diagnosis, Antilock Brake System for ABS diagnosis and Heating and Air Conditioning for Heater and A/C Control Assembly diagnosis. Engine Control Module
Antilock Brakes / Traction Control Systems
Heating and Air Conditioning
^ Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring for a voltage drop with the system operational (under load).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems refer to Diagnostic Aids. Diagnostic Aids