Flow of Diagnosis

1. Verify the customer's concern by operating the switches to duplicate the condition.
2. Inspect to determine if any of the following mechanical or electrical concerns apply:
^ Damaged switch.
^ Low fluid level (washer system).
^ Damaged or Incorrect ignition key.
^ Fuse junction panel fuse(s):
- 2 (5A), 14 (5A), 12 (10A), 19 (10A), 21 (10A), 30 (25A)
^ Power distribution box main fuse(s):
- C (60A) and D (60A)
^ Circuit wiring.

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 the inspection, connect the Rotunda New Generation Star (NGS) Tester 007-00500 or equivalent to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the NGS tester menu. If the NGS tester does not communicate with the vehicle:
^ check that program card is properly installed.
^ check connections to vehicle.
^ check ignition switch position.

If the NGS tester still does not communicate with the vehicle, refer to the New Generation Star Tester manual.

5. Perform DATA LINK DIAGNOSTIC TEST using the NGS tester. If the NGS tester responds with:
^ CKT 914 or CKT 915 = 000000003 or ALL MODULES NO RESPONSE/NOT EQUIPPED diagnose the Communication System, J1850 communication network concern.
^ CKT 70 = 00000000F or ALL MODULES NO RESPONSE/NOT EQUIPPED, diagnose the Communication System, ISO 9141 communication link concern.
^ NO RESPONSE/NOT EQUIPPED for Generic Electronic Module (GEM), go to Pinpoint Test A.
^ SYSTEM PASSED for the Generic Electronic Module (GEM), retrieve and record continuous diagnostic trouble codes (DTCs), erase continuous DTCs, then execute Self Test Diagnostics for the Generic Electronic Module (GEM).

6. If DTCs retrieve are related to the concern, go to the Generic Electronic Module (GEM) Diagnostic Trouble Code (DTC) Index to continue diagnostics.
7. If no DTCs related to the concern are retrieved, go to the Symptom Chart to continue diagnostics.

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