FixVault

Auxiliary Heater Control Module (AHCM)

AUXILIARY HEATER CONTROL MODULE (AHCM) DTC CHART

DTC Description Action to Take
B1317 Battery Voltage High GO to PINPOINT TEST R .
B1318 Battery Voltage Low GO to PINPOINT TEST R .
B1342 ECU Is Faulted INSTALL a new electric heater. REFER to CLIMATE CONTROL . TEST the system for normal operation.
U0100 Lost Communication with ECM/PCM CLEAR the DTCs. REPEAT the self-test. If the DTC returns, REFER to MODULE COMMUNICATIONS NETWORK to diagnose the lost communication with the PCM.
U0140 Lost Communication With Body Control Module This DTC can set because the BCM is unable to communicate with the AHCM over the CAN bus. CARRY OUT a self-test of the BCM. If the scan tool indicates that the BCM is not responding, REFER to MODULE COMMUNICATIONS NETWORK to diagnose the network communication concern. If BCM DTCs are present, REFER to MULTIFUNCTION ELECTRONIC MODULES .