RL V6-3.5L (2007)
8. Each ECU that expects to receive the door lock switch message from the driver's MPCS unit will transmit DTCs for the message that it did not
receive.
Since there is a break in the communication circuit, the door lock switch message could not be received by the MICU, the relay control module, the
gauge control module, the keyless access control unit, or the OnStar control unit* (if applicable). Each of these units will set "loss of communication"
error codes for the message(s) they did not receive. There may be multiple communication DTCs if the unit that has become disconnected from the
network would normally transmit multiple messages during the communication line test. For example, the driver's MPCS unit sends the door switch
message and door lock switch message during the communication circuit test.
*:'05-06 models
Diagnostic Trouble Codes (DTC)
There are three types of DTCs used by the CAN networks.
