U1192

DTC U1001- U1254

Circuit Description

Each module connected to the class 2 serial data circuit monitors serial data communication during normal vehicle operation. Operating parameters and other information are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for state of health monitoring. Once a module learns another modules identification number, it will monitor the serial data for that modules node alive message. Each module that sends critical operating parameters is required to send a node alive message every two seconds. When no message is detected from a learned module for 5 seconds, DTC U1001-U1254 will set.

DTC Descriptors

This diagnostic procedure supports the following:
- DTC U1016 Lost Communications With Powertrain Control Module (PCM).
- DTC U1040 Lost Communications With Electronic Brake Control Module (EBCM).
- DTC U1064 Lost Communications With Body Control Module (BCM).
- DTC U1088 Lost Communications With Sensing and Diagnostic Module (SDM).
- DTC U1096 Lost Communications With Instrument Panel Cluster (IPC).
- DTC U1128 Lost Communications With Radio.
- DTC U1176 Lost Communications With Remote Function Actuation (RCDLR).
- DTC U1192 Lost Communications With Vehicle Theft Deterrent (VTD).

Conditions for Running the DTC

- Battery Voltage is 9-16 volts.
- DTCs U1300, U1301, or U1305 are not current.
- Serial data communication has begun.

Conditions for Setting the DTC

- A node alive message from a learned module has not been detected for 5 seconds.

Conditions for Clearing the DTC

- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the ignition is cycled 100 times without a repeat of the malfunction.

Diagnostic Aids

When more than one Loss of Communication DTC is set in a single module or among multiple modules, diagnose the DTCs in the following order:
1. Current DTCs before history DTCs except as specified in the diagnostic tables.
2. The DTC which is reported the most times.
3. From the lowest number DTC to the highest number DTC.

Test Description

The number below refers to the step number on the diagnostic table.
6. The module which was not communicating due to an open in the class 2 serial data circuit may have set Loss of Communication DTCs for those modules that it was monitoring.
8. The modules which can communicate indicate the module which cannot communicate. You must clear the DTCs from these modules to avoid further misdiagnosis.