Normal Operation
The wrench reconfigurable telltale can be turned on by any one of three modules. The powertrain control module (PCM) provides the electronic throttle control status, the transmission control module (TCM) provides transmission status and the four wheel drive (4WD) control module (if equipped) provides a status of the 4WD system to the instrument cluster. Each module monitors the powertrain for their respective function and provides the instrument cluster with the operating status over the high speed controller area network (HS-CAN) communication bus. When a fault condition exists in any of the monitored systems, the PCM, TCM or 4WD (if equipped) control modules provide the instrument cluster with a message to turn on the wrench warning indicator.
If the electronic throttle control message is missing or if the data is deemed invalid by the instrument cluster for greater than 5 seconds, the instrument cluster sets DTC U0100 and defaults the wrench reconfigurable telltale ON. If the O/D off message is missing or invalid for greater than 5 seconds, the instrument cluster sets DTC U0101 and defaults the wrench reconfigurable telltale ON. If equipped with 4WD and the 4WD status message is missing or invalid for more than 5 seconds, the instrument cluster sets DTC U0102 and defaults the wrench reconfigurable telltale ON.
NOTE: If U0100 is set in the instrument cluster other symptoms may also be present such as an inoperative speedometer, tachometer or temperature gauge. If U0101 is set, other symptoms may include the O/D off indicator ON. If DTC U0102 is set, other symptoms may include the 4x4, 4x4 LOW or 4x4 AUTO reconfigurable telltales may be inoperative.
Possible Causes
- Electronic throttle control concern
- Transmission concern
- 4WD concern (if equipped)
- Instrument cluster