Test C - Yellow & Red Lights On Steady
- Check master cylinder fluid level. If fluid level is low, check for leaks, refill reservoir and retest system. If fluid level is okay, remove cap from master cylinder. Carefully push down on float in reservoir. If float does not move downward, replace master cylinder reservoir. Retest system. If float moves downward, reinstall master cylinder cap.
- Turn ignition on. Check parking brake and release if applied. If both lights go off, replace diode/resistor. See Figure -Figure . If both lights stay on, remove parking brake switch and diesel low vacuum switch (if equipped) connectors.
- If both lights go off, replace diode/resistor. If both lights stay on, attempt to retrieve trouble code. See RETRIEVING TROUBLE CODES . If trouble code is retrieved, go to appropriate code. See RETRIEVING TROUBLE CODES . If both lights are still on steady, turn ignition off.
- Unplug fluid level sensor connector, at master cylinder. Connect a jumper wire between the 2 Purple/Yellow and Purple/White wires. Turn ignition on. If both lights go off, replace master cylinder reservoir. If both lights stay on, turn ignition off.
- Unplug control module connector. Turn ignition on. If both lights go off, replace control module. If both lights stay on, check for short in fluid level and parking brake switch wiring. Repair short in wiring and retest system.