B1640

DTC B1640

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions 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

The heated mirror will be disabled.

Conditions for Clearing the DTC

* A current DTC will clear when the fault is no longer present.

* A history DTC will clear after 40 fault free ignition cycles.

Reference Information

Schematic Reference

Outside Rearview Mirror Schematics Outside Rearview Mirror Schematics

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

Outside Mirror Description and Operation (Power Mirrors) Outside Mirror (Power Mirrors)Outside Mirror Description and Operation (Heated Mirrors) Outside Mirror (Heated Mirrors)

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool References

Control Module References Control Module References for scan tool information.

Circuit/System Verification

Ignition ON, press the rear window defogger switch. The rear window defogger and both heated mirrors should become warm.

Circuit/System Testing

1. Ignition OFF, disconnect the X3 harness connector at the appropriate door module.

2. Ignition ON, verify a test lamp does not illuminate between the control circuit terminal 7 and ground.

• If the test lamp illuminates, test the control circuit for a short to voltage.

3. Ignition OFF, test for infinite resistance between the control circuit terminal 7 and ground.

• If less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, test or replace the applicable rearview mirror face.

4. Test for 5-10 ohms of resistance between the control circuit terminal 7 and the low reference circuit terminal 3.

• If not within the specified range, test the control circuit and the low reference circuit for an open/high resistance. If the circuits test normal, test or replace the appropriate rearview mirror face.

5. If all circuits test normal, test or replace the door module.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Outside Rearview Mirror Glass Replacement Outside Rearview Mirror Glass Replacement

* Control Module References Control Module References for DDM or PDM replacement, setup and programming