C1148 Code: Meaning, Causes, and Symptoms | OBD2 Codes

C1148 – Speed Wheel Sensor RF Coherency Fault


C1148 Possible Symptoms


Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)


C1148 Possible Causes


ABS RF Wheel Speed Sensor / Wiring intermittently open/shorted,Tone wheel cracked/slipping on hub/axle/CV shaft,Faulty / intermittent connection at the Anti-Lock Brake Control Module (ABCM or EBCM),Faulty Anti-Lock Brake Control Module


C1148 Description


When the driver stops too fast, and one or more wheels begin to lock up, the ABS system takes over. It sees the wheel or wheels slowing down too rapidly by way of wheel speed sensors. When this happens, it shuts off brake fluid to the wheel with the inlet valve/coil, and releases the pressure with an outlet valve/coil. The Wheel Speed Sensor RF is typically found on vehicles with 4 Wheel Anti-Lock Brakes. The ABS system checks to be sure that the sensor electrical circuit is ok every time the key is turned on and the ABS module is powered up. It checks it again once vehicle speed reaches a preset speed (usually 5-15 mph).If there is a problem with the sensor or if the signal from the sensor is erratic, the ABS module will communicate over a data bus to the instrument cluster to turn on the amber Anti-Lock Light and the Red Brake Warning Light, and ABS will be disabled. In this case, the module has checked the right front wheel speed sensor/wiring and found the circuit has an electrical problem. This sets a C1148 in memory.