Initial Inspection and Diagnostic Overview

NOTE: Before starting electrical diagnosis, check for mechanical binds by manually operating door locks. Operate lock system several times from each switch while observing the operation of all door locks. Be sure battery is fully charged.

1. Verify the customer's concern by operating the electronic door lock control system to duplicate the condition.
2. Inspect to determine if one of the mechanical or electrical concerns apply:

Mechanical
- Binding Latches

Electrical
- Open Fuses:
Power distribution box - Circuit Breaker (door locks/seat motors) (20 A)
Fuse junction panel Circuit Breaker 14 (20 A) and Fuse 8 (15 A)
- Loose connectors
- Corroded connectors

3. If inspection reveals an obvious concern that is readily serviced, correct the concern before continuing with Inspection and Verification.
4. If a concern remains after inspection, connect the Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent to the Data Link Connector (DLC) located beneath the instrument panel to perform DATA LINK DIAGNOSTICS test.

- If the NGS responds with NO RESPONSE/NOT EQUIPPED for the driver door module, go to Pinpoint Test C. C: No Communication With Driver Door Module (DDM)

- If the NGS responds with NO RESPONSE/NOT EQUIPPED for the lighting control module, go to Pinpoint Test D. D: No Communication With Lighting Control Module

- If the DATA LINK DIAGNOSTICS test is passed for the driver door or lighting control module(s), retrieve continuous Diagnostic Trouble Codes (DTCs) and execute Self Test Diagnostics for the driver door or lighting control module to retrieve current DTCs.

5. If self test is passed and no DTCs are retrieved, go to the Symptom Chart to continue diagnostics. Symptom Related Diagnostic Procedures
6. If DTCs are retrieved for the driver door module, go to the Driver Door Module (DDM) Diagnostic Trouble Code (DTC) Index to continue diagnostics. Driver Door Module (DDM) Diagnostic Trouble Code (DTC) Index
If DTCs are retrieved for the lighting control module, go to the Lighting Control Module (LCM) DTC Index to continue diagnostics. Lighting Control Module Diagnostic Trouble Code (DTC) Index
7. If the driver door module cannot be accessed by the NGS tester, go to Pinpoint Test C. C: No Communication With Driver Door Module (DDM)
If the lighting control module cannot be accessed by the NGS tester, go to Pinpoint Test D. D: No Communication With Lighting Control Module

Rotunda Service Bay Diagnostic System (SBDS (R)) 001-00001 may also be used to diagnose this system.