Normal Operation
The PCM calculates the vehicle speed from the transaxle Output Shaft Speed (OSS) sensor input and from the tire size and axle ratio configuration in the PCM Vehicle Identification (VID) block. The PCM provides the Instrument Cluster (IC) with the vehicle speed data over the High Speed Controller Area Network (HS-CAN) bus. The IC monitors the vehicle speed input and commands the speedometer with a corresponding movement of the pointer.
If the IC does not receive the vehicle speed data from the PCM for 5 seconds or less, the IC defaults the speedometer to the last setting, based upon the last known good vehicle speed message. If the IC does not receive the vehicle speed data from the PCM for more than 5 seconds or if the data received is deemed invalid, the IC sets DTC U0100 in continuous memory and defaults the speedometer to 0 km/h (0 mph).
This pinpoint test is intended to diagnose the following:
- PCM
- IC