Test L: Brake Warning Indicator Inoperative Or Always On
WARNING: This page is about a different car, the 2002 Lincoln Navigator and 2002 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After making any repairs, clear DTCs and perform self-test.
- Check basic brake system operation. If brake operation is okay, go to next step. If brake operation is faulty, diagnose and repair mechanical brake problem. See appropriate DISC/DRUM article in BRAKES.
- Check parking brake control and brake fluid level. If parking brake is fully disengaged and brake fluid level is correct, go to next step. If parking brake is not disengaged or brake fluid level is not correct, disengage parking brake and/or adjust fluid level as necessary.
- Turn ignition switch to LOCK position. Disconnect parking brake switch harness connector C254. Measure resistance between parking brake switch terminal (component side) and ground while engaging and fully disengaging parking brake. Resistance should be 5 ohms or less with parking brake engaged and more than 10 k/ohms with parking brake fully disengaged. If resistance is as specified, go to next step. If either resistance is not as specified, replace parking brake switch.
- Turn ignition switch to LOCK position. Disconnect instrument cluster 20-pin harness connector or C238. Measure resistance of Light Green/Red wire between parking brake switch harness connector and instrument cluster harness connector C238 terminal No. 17. Measure resistance between ground and instrument cluster harness connector C238 terminal No. 17 (Light Green/Red wire). See Figure. Resistance should be 5 ohms or less between instrument cluster harness connector and parking brake switch harness connector, and more than 10 k/ohms between instrument cluster harness connector and ground. If resistance is as specified, go to next step. If either resistance is not as specified, repair open or short to ground in Light Green/Red wire between parking brake switch and instrument cluster.
- Disconnect brake fluid level switch 3-pin harness connector C162. Measure resistance between terminals No. 1 and 3 at brake fluid level switch (component side). Measure resistance between terminals No. 2 and 3 at brake fluid level switch (component side). See Fig 1. Resistance should be more than 10 k/ohms between brake fluid level switch terminals No. 1 and 3, and 5 ohms or less between terminals No. 2 and 3. If resistance is as specified, go to next step. If either resistance is not as specified, replace brake fluid level switch.
- Measure resistance in Dark Green/Yellow wire between brake fluid level switch harness connector terminal No. 3 and instrument cluster harness connector C238 terminal No. 18. Measure resistance of Tan/Light Green wire between brake fluid level switch harness connector terminal No. 2 and at instrument cluster harness connector C238 terminal No. 19. If resistance is 5 ohms or less on both circuits, go to next step. If resistance is more than 5 ohms on either circuit, repair open in Dark Green/Yellow or Tan/Light Green wire between instrument cluster and brake fluid level switch. See WIRING DIAGRAMS .
- Measure resistance between ground and brake fluid level switch harness connector C162 terminal No. 1 (Black wire). If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open in Black wire between brake fluid level switch and ground. Ground point is located at left front radiator support.
- Disconnect all instrument cluster harness connectors. Inspect harness connectors for corrosion and pushed out pins. Connect all instrument cluster harness connectors, ensuring they are connected correctly. Operate system and verify if concern is still present. If concern is still present, replace instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. If concern is not present, system is operating correctly at this time. Clear DTCs and perform self-test.