• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The wheel speeds are detected by active wheel speed sensors. Each wheel speed sensor receives a 12 V reference voltage from the electronic brake control module (EBCM) and provides an alternating current square wave signal to the EBCM. As the wheel spins, the EBCM uses the frequency of the square wave signal to calculate the wheel speed. The EBCM sends the wheel speed information as a high speed controller area network (CAN) serial data message.
Vehicle speed is greater than 14 km/h (9 MPH).
The engine control module (ECM) detects wheel speed differences between one wheel and the others.
Specific subsystems will not function or operate in degraded mode.
A current DTC clears when the diagnostic runs and passes.
Antilock Brake System Schematics
Control Module References for scan tool information
Ignition ON, observe the EBCM scan tool Wheel Speed Sensor parameters. The reading should be the same speed on all sensors when driving in a straight line at a speed greater than 20 km/h (13 MPH).
⇒ | If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose that DTC prior to this diagnostic. |
⇒ | If the DTC resets, replace the module that set the DTC. |
• | Perform the Diagnostic Repair Verification after completing the diagnostic procedure. |
• | Control Module References for module replacement, setup and programming |