Operation CHARM: Car repair manuals for everyone.

Antilock Brakes / Traction Control Systems: Service and Repair


Before performing any service procedure on the ABS system, the following precautions should be followed:
1. The control module must be disconnected before performing any electric welding on these vehicles.
2. Use caution not to subject control module to a maximum heat of 203°F for brief periods, or a maximum of 184°F for longer than 2 hours.
3. After replacement of any ABS component, the entire ABS system should be tested.
4. Ensure inlet and outlet brake lines are properly routed.
5. Do not use a fast charger for starting engine.
6. Never disconnect battery from vehicle when engine is running.
7. Do not connect or disconnect control module electrical connector with ignition switch in On position. Ensure all harness connectors are securely connected.
8. No screws on the modulator valve should be loosened. If screws are loosened, it is no longer possible to get brake circuit leak-tight.
9. When replacing modulator valve, it should be removed through access panel in rear storage compartment. Ensure vehicle interior and exterior are protected to avoid damage from brake fluid spillage. Do not remove bottom of storage compartment to replace modulator valve.
10. Ensure rear storage compartment is wiped clean after replacing modulator valve.
11. Do not support suspension components by wheel speed sensor wires.
12. Wheel speed sensors are a tight fit into knuckle, but should be pushed in by hand. Do not hammer sensors into position.
13. Each replacement wheel speed sensor is identified with a white tag, located approximately 3/4 inch from neck of sensor, labeled L (left), or R (right).
14. Tire and wheel assemblies should be removed when replacing wheel speed sensors.
15. Wheel speed sensors should be given an anti-corrosion coating, No. 9981128 or equivalent, before installation to prevent corrosion. Do not use grease.
16. Use caution not to use silicone type brake fluid.

ON-VEHICLE SERVICE

After all diagnosis and repairs are completed, road test the vehicle to ensure proper ABS operation and that the SERVICE ABS light does not illuminate. If the Tech 1 was used for diagnosis, disconnect it from the ALDL connector and turn the ignition Off before road testing the vehicle. This is required to reset the EBCM, it is disabled during Tech 1 diagnostics and does not reset until serial data communication is stopped and ignition power is lost.