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.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Outside Rearview Mirror Schematics Connector End View Reference: Mirror Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does DTC B1640 or B1645 set as current in the driver door module (DDM) or passenger door module (PDM)? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections |
3 |
Does DTC B1640 or B1645 set as current in the DDM or PDM? | Go to Step 5 | Go to Step 4 |
4 | Inspect for poor connections at the heated mirror. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the appropriate door module . Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 7 |
6 | Replace the heated mirror. Refer to Outside Rearview Mirror Replacement . Did you complete the replacement? | Go to Step 8 | -- |
7 | Replace the appropriate door module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 8 | -- |
8 |
Does the DTC reset? | Go to Step 2 | System OK |
