Initial Inspection and Diagnostic Overview

1. Check the CIG LTR Fuse for an open. If the Fuse is blown, check CKT 440 for a short to ground.
2. Check that G200 is clean and tight.
3. If all components are not accessible with a Scan Tool, check for an open in CKT 800 between the Data Link Connector terminal "9" and S237.
4. If a single component is not accessible with a Scan Tool, check for an open in CKT 800 between S237 and the component. Check the Class II Serial Data Line between the Data Link Connector terminal "2" and the Powertrain Control Module (PCM). Also check C101 for a poor connection. If the wires are OK, refer to Antilock Brake System for ABS diagnosis and to Air Bags (Supplemental Restraint System) for Supplemental Air Restraint diagnosis.

Testing and Inspection
^ 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 General Troubleshooting Procedures). Diagnostic Aids
^ Refer to System Diagnosis.