Antilock Brakes / Traction Control Systems: Service and Repair

ABS Component Repairs

WARNING:
^ ABS is basically maintenance free.
^ Specialized knowledge is required to carry out service or repair work on this system.
^ Failure to read and follow the safety precautions that follow may result in system damage and loss of vehicle safety.

- Before disconnecting the ABS control module connector, be sure the ignition is switched off. Heat and sparks can cause damage.
- The ABS control module connector must be disconnected before carrying out any welding operations with electric welding equipment on or near the vehicle.
- Remove the ABS control module before exposing the vehicle to high temperature, as in a paint drying oven. Temperature must never exceed 90°C (194°F), and should not exceed 85°C (185°F) for more than 2 hours.
- Disconnect the battery negative terminal before charging the battery, and before removing the ABS hydraulic unit.
- When reconnecting the battery, make sure the terminals are tightened properly.
- Do not drive the car with ABS test equipment connected.

Non-ABS Component Repairs
- After repairs to the brake system that do not directly affect ABS components, a simple function check is sufficient:
Switch ignition on.
ABS warning light in instrument panel should come on.
Drive vehicle at speed above 4 mph (6 km/h).
ABS warning light must go out.
- Check as described above after work during which any of the following components were repaired or replaced:
Brake pads and/or brake discs
Brake hoses
Brake servo or master cylinder
Brake lines and parking brake components

ABS Testing Following Repairs
- A check of the entire system must be made after any repairs involving the following components:
ABS hydraulic unit
ABS control module
ABS wheel speed sensors
ABS wiring harness
Replacement of brake system assemblies (e.g. brake lines replaced due to accident damage)
- For a check of the entire system refer to On Board Diagnostic in System Diagnosis. Testing and Inspection

WARNING:
^ ABS should not be activated during normal braking, but must be activated automatically when wheel "lock-up "or "skid" conditions are detected
^ ABS function must be tested at least once during the final test drive.
^ Safely apply the brakes in such a way that the ABS system will be activated