ABS Troubleshooting for Trucks, Trailers, and Buses
STEP 1: Identification of the vehicle's ECU by part number
Anti-Lock Brake System (ABS) consists of several key components: an Electronic Control Unit (ECU), wheel speed sensors, modulator valves, and exciter rings. The ECU is the brain of the system. It receives information from the sensors and sends signals to the ABS valves. In effect the ECU controls the anti-lock brake and automatic traction control systems, as well as the diagnostic functions.
The ECU continually checks itself for proper operation. If it detects a malfunction or failure in the electrical or electronic system, it will shut down that part of the ABS affected by the problemor the entire ABSdepending upon the system and the problem. When this happens, the dashboard ABS warning lamp lights.
Operating the search function correctly
This website offers the user two ways to identify a vehicle's ECU. The quickest, and most straightforward, is if you already know the part number of the ECU. If this is not known, or not immediately available, then, as an alternative, it is possible to search by ECU make and model. The identity tag on a vehicle's ECU is the starting point, and will provide some or all of the following information: manufacturer, model or version of ECU, ABS configuration, and part number. A typical example is shown below.