锟斤拷 If not within the specified range, test both control circuits for an open/high resistance. If the circuits test normal, test or replace the
rearview mirror.
5. Test for 40-100 ohms between the control circuit terminal 2 and the control circuit terminal 6.
锟斤拷 If not within the specified range, test both control circuit for an open/high resistance. If the circuits test normal, test or replace the rearview
mirror.
6. If all circuits test normal, replace the door module.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Outside Rearview Mirror Motor Replacement (See: Body and Frame/Mirrors/Power Mirror Motor/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for DDM or PDM replacement, setup, and
programming
B1640
DTC B1640
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B1640 01
- Mirror Heater Circuit Short to Battery
DTC B1640 02
- Mirror Heater Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
The Driver Door Module (DDM) and Passenger Door Module (PDM) supply voltage to the outside rearview mirror heater elements upon receipt of
a message from the HVAC module indicating that the rear defrost system is active. The door module supplies B+ through the driver/passenger
mirror heating element control circuit when a request is seen. Ground is applied through the driver/passenger mirror heating low reference circuit.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B1640 01
A short to voltage is detected on the mirror heating element control circuit while the heated mirrors are inactive.
B1640 02
A short to ground is detected on the mirror heating element control circuit while the heated mirrors are active.
Action Taken When the DTC Sets
