U1064 Loss of Communications With BCM - IPC

DTC U1064 Loss Of BCM Communication:

CIRCUIT DESCRIPTION
The instrument cluster receives a state of health message from modules whose source IDs it has learned. If the instrument cluster does not see a state of health message from the Body Control Module (BCM), a Diagnostic Trouble Code (DTC) will set.

CONDITIONS FOR SETTING THE DTC
The instrument cluster does not receive a state of health message from the BCM.

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC U1064 in the instrument cluster memory.
^ SERVICE VEHICLE SOON will be displayed for this DTC.

CONDITIONS FOR CLEARING THE DTC
^ Under all fault conditions, the ignition must be cycled before this DTC can change from current to history.
^ The instrument cluster detects a state of health message from the BCM.
^ A history DTC will clear after 100 drive cycles if the condition for the malfunction is no longer present.
^ Using a scan tool.

DIAGNOSTIC AIDS
The following conditions may cause an intermittent malfunction to occur:
^ An intermittent open or short to ground in circuit 1037.
^ Poor connections at the instrument cluster, or the BCM.

TEST DESCRIPTION
Numbers below refer to the step numbers on the diagnostic table.
1. Always perform the Instrument Cluster Diagnostic System Check before attempting to diagnose a DTC U1064.
2. The scan tool tries to communicate with the BCM.
3. The scan tool tries to communicate with the other modules.
4. This test checks for a poor connection at the BCM.
6. This test checks for an open in circuit 1037.
7. This test checks for a short to ground in circuit 1037.