DTC C128C GMC

Description

The DSA control module receives wheel speed signals from the ABS control module. The ABS control module converts the wheel sensor AC signal into a pulsed signal for the DSA control module. The signal is pulsed between approximately 0 V and battery voltage. It has a fixed pulse ratio (%duty ≈ 50 %) where the frequency changes with the wheel speed. Depending on the current wheel speed signal, DTCs DSA-311, DSA-312, DSA-313 or DSA-314 are stored if the vehicle speed exceeds 8 km h and the DSA control module registers that: Wheel speed increase or reduction is too great. The speed of a wheel is less or the same as half the speed of one of the rear wheels. The speed signal varies considerably.