Test E: Brake Indicator Always On
- If hydraulic brakes diagnostic system check has been performed, go to next step. If hydraulic brakes diagnostic system check has not been performed, go to HYDRAULIC BRAKES DIAGNOSTIC SYSTEM CHECK under DIAGNOSTIC SYSTEM CHECKS in BODY CONTROL MODULES - DEVILLE article.
- Inspect brake fluid level. If brake fluid level is okay, go to next step. If brake fluid level is low, top off fluid level and check for brake fluid leak.
- Turn ignition on. Disengage parking brake. Connect scan tool to Data Link Connector (DLC). Observe PARK BRAKE SWITCH parameter in INSTRUMENT PANEL CLUSTER data list. If PARK BRAKE SWITCH parameter is OFF, go to next step. If PARK BRAKE SWITCH parameter is not OFF, go to step 5.
- Using scan tool, observe BRAKE FLUID LEVEL parameter. If BRAKE FLUID LEVEL parameter is OK, check for faulty connections at brake light switch harness connector. If BRAKE FLUID LEVEL parameter is not OK, go to step 6.
- Turn ignition off. Disconnect parking brake warning light switch connector located on parking brake pedal assembly. Turn ignition on. Using scan tool, observe PARK BRAKE SWITCH parameter. If PARK BRAKE SWITCH parameter is OFF go to step 9. If PARK BRAKE SWITCH parameter is not OFF, go to step 7.
- Turn ignition off. Disconnect brake fluid level switch located on bottom of master cylinder brake fluid reservoir. See Fig 1. Turn ignition on. Using scan tool, observe BRAKE FLUID LEVEL parameter. If BRAKE FLUID LEVEL parameter is OK, go to step 10. If BRAKE FLUID LEVEL parameter is not OK, go to step 8.
- Check for a short to ground in Light Blue wire between parking brake warning light switch harness connector "C" and IPC connector C2 terminal B1. See Fig 2. If no problem was found, go to step 11. If a problem was found and corrected, go to step 15.
- Check for short to ground in Purple wire between brake level switch harness connector terminal "A" and IPC harness connector C2 terminal B4. See Figure and Fig 3
. If no problems are found, go to step 11. If any problems are found and corrected, go to step 15.
- Check for poor connections at parking brake warning light switch connector. If no problems are found, go to step 12. If any problems are found and corrected, go to step 15.
- Check for poor connections at brake fluid level switch connector. If no problems are found, go to step 13. If any problems are found and corrected, go to step 15.
- Check for poor connections at IPC harness connectors. If no problems are found, go to step 14. If any problems are found and corrected, go to step 15.
- Replace parking brake warning light switch. See PARKING BRAKE WARNING LIGHT SWITCH under REMOVAL & INSTALLATION. After repairs, go to step 15.
- Replace brake fluid level switch. See BRAKE FLUID LEVEL SWITCH under REMOVAL & INSTALLATION. After repairs, go to step 15.
- Replace IPC. See INSTRUMENT PANEL CLUSTER under REMOVAL & INSTALLATION. After repairs, go to next step.
- After repairs, recheck operation of BRAKE indicator. If indicator operates properly, repair is complete. If indicator does not operate properly, return to step 2.
Courtesy of GENERAL MOTORS CORP.
Courtesy of GENERAL MOTORS CORP.
Courtesy of GENERAL MOTORS CORP.