U1016 Loss of Communications With PCM - IPC

DTC U1016 Loss Of PCM 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 Powertrain Control Module (PCM), 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 instrument cluster.

ACTION TAKEN WHEN THE DTC SETS
^ Stores a DTC U1016 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 PCM.
^ 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 1049.
^ Poor connections at the instrument cluster, or the PCM.

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 U1016.
2. The scan tool tries to communicate with the PCM.
3. The scan tool tries to communicate with the other module.
4. This test checks for a poor connection at the PCM.
6. This test checks for an open in circuit 1049.
7. This test checks for a short to ground in circuit 1049.