Vehicle Speed Signal

The vehicle speed input signal is provided by the ABS/ASC control module. The wheel speed sensor input is processed by the ABS and made available to the MS41.1 Control Module as a digital square wave signal. The frequency of the signal is proportional to the speed of the vehicle.

The vehicle speed input signal is continuously monitored as part of the OBD II emission requirements. The control module monitors the plausibility of the speed input against engine RPM and load.

If a malfunction occurs the control module will limit the maximum RPM of the engine and the Check Engine Lamp will illuminate when the criteria for OBD II monitoring are satisfied.