Antilock Brakes / Traction Control Systems: Service Precautions

ELECTRICAL AND ELECTRONIC

^ Never disconnect the battery from the electrical system with the engine running.

^ Never connect or detach the Electronic Control Unit (ECU) harness connector with the ignition switch ON.

^ Before performing electric welding procedures, unplug the ECU harness connector.

^ When painting, the following temperature limitations apply: Do not expose the ECU to temperatures above 95~C (203~F) except for brief periods. Do not expose the ECU to temperatures above 85~C (185~F) for longer than two hours.

^ Do not use a fast charger for engine starting. Disconnect the battery from the vehicle electrical system when fast charging the battery.

^ Do not hang the suspension components by the wheel speed sensor cables; these cables are delicate.

^ Take extreme care not to damage the reluctor rings. Also, do not hammer the tooth rings, they must be pressed into hubs. Striking these can cause demagnetization or polarization, affecting the accuracy of the speed signal returning to the Anti-lock Brake System (ABS) control module.

^ When servicing or replacing ABS components including the Anti-lock Brake Control Module (ABCM), wheel sensors, hydraulic modulator, or wiring harness, verify proper ABS operation using approved procedures.


BRAKE SYSTEMS

^ Use care when handling brake fluid to avoid paint or plastic component damage.

^ Never use DOT 5 silicone brake fluids in the Bosch ABS 3 system; silicone brake fluid will seriously damage ABS hydraulic components.

^ When adding fluid to the Bosch ABS 3 anti-lock system, use only DOT 3 brake fluid from a clean, sealed container. Brake fluids meeting DOT 3 specifications are glycol-based. Glycol-type brake fluids are NOT compatible with silicone-based fluids. Do not use brake fluid from any container which is wet with water. The use of improper brake fluid, water contaminated, or mineral oil contaminated brake fluid will cause deterioration of rubber ABS components.

^ Make absolutely sure the brake lines are properly routed after service.

NOTE: Always carefully note the routing, position, mounting and location of ABS wiring, connectors, clips, brackets, etc. Anti-lock components are extremely sensitive to Electro-Magnetic Interference (EMI). Proper mounting is critical when servicing ABS components.

^ Coat the wheel speed sensors with an anticorrosion compound before installation. Do not use grease.