B1645
DTC B1640 or B1645
CIRCUIT DESCRIPTION
The driver door module (DDM) and passenger door module (PDM) supply battery voltage to the mirror heating element supply voltage circuit upon receipt of a class 2 message from the body control module (BCM) indicating that the rear defrost system is active. The DDM and PDM also supply a constant ground for the mirror heating elements.
DTC DESCRIPTORs
This diagnostic procedure supports the following DTCs:
- DTC B1640 Left Front Mirror Heater Circuit
- DTC B1645 Right Front Mirror Heater Circuit
CONDITIONS FOR RUNNING THE DTC
- System voltage between 9-16 volts
- Ignition switch is in the ON position
CONDITIONS FOR SETTING THE DTC
When the DDM and PDM supply battery voltage to the mirror heating element supply voltage circuit and it is shorted to ground.
ACTION TAKEN WHEN THE DTC SETS
The DDM and PDM will ignore the class 2 message and stop supplying battery voltage on the shorted circuit.
CONDITIONS FOR CLEARING THE DTC
When the short circuit is no longer present, the DDM/PDM will clear the current DTC and store the DTC as a history DTC. The history DTC will clear after 50 fault-free ignition cycles or in response to a scan tool command.
TEST
