Antilock Brakes / Traction Control Systems: Service Precautions

CAUTION: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. It the above conditions are not followed, parts or system damage could result.


REPLACEMENT TIRE
Tire size can affect the performance of the Rear Wheel Antil Lock (RWAL) system. Replacement tires must be the same size, load range, and construction on all four wheels

SERVICE PRECAUTIONS
The RWAL system is basically maintenance free. When doing work on this system, the following must be observed:

- Before doing welding work on the vehicle with an electric welding unit, turn the ignition switch "OFF" and disconnect the Electronic Brake Control Module (EBCM) connectors.

- Do not use a fast charger for starting the engine.

- Disconnect the negative battery cable when fast charging.

- Never disconnect the the battery from the vehicle electrical system with the engine running.

- Make sure all wiring harness connectors are securely connected.

- Be sure to use the correct EBCM for the system being serviced. The 3500 MD uses the Zero Pressure Rear Wheel Anti Lock (ZPRWAL) EBCM with the gray electrical connector. All other models use the Rear Wheel Anti Lock (RWAL) EBCM with the black electrical connector. Failure to use the correct EBCM will result in a system malfunction.

- Always note the routing, position, mounting, and location of all components, wiring, connectors, clips, brackets, brake pipes, etc., when servicing the Rear Wheel Antil Lock (RWAL) system. Speed sensor wiring, routing, and retention is especially important to help prevent false signals due to electrical noise picked up by the wiring. Proper system operation can only be achieved if the system is restored to its original equipment condition.

The above mentioned items do not cover every possibility, but must be followed when working on RWAL. When doing service work, become familiar with RWAL, and how they may be interrelated with other components on the vehicle.