Diagnostic Instructions
DTC Descriptors
DTC B1544 01: Mirror Motors Common Circuit Short to Battery
DTC B1544 02: Mirror Motors Common Circuit Short to Ground
DTC B1544 04: Mirror Motors Common Circuit Open
DTC B1600 01: Mirror Motor Vertical Circuit Short to Battery
DTC B1600 02: Mirror Motor Vertical Circuit Short to Ground
DTC B1600 04: Mirror Motor Vertical Circuit Open
DTC B1605 01: Mirror Motor Horizontal Circuit Short to Battery
DTC B1605 02: Mirror Motor Horizontal Circuit Short to Ground
DTC B1605 04: Mirror Motor Horizontal Circuit Open
Circuit/System Description
The driver door module (DDM) and passenger door module (PDM) each provide motor control output functions for their respective mirrors. These output controls allow each door module to command their respective power mirrors in horizontal and vertical positions.
The power mirror switch is integrated into the DDM. When the power mirror switch is activated to the up, down, left or right positions, the DDM responds by commanding the driver mirror to the desired position. The DDM also sends a GMLAN serial data message to
the PDM to command the passenger mirror to the appropriate position. Each door module commands their respective mirror motors by applying a ground or voltage to the control circuit, depending on the desired mirror position. For more detailed information concerning
power mirror operation refer to
Outside Mirror Description and Operation
.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
| • | The DDM or PDM detects a short to voltage, short to ground or an open in the mirror motor control circuits. |
| • | Condition must be present for 2 seconds. |
Actions Taken When the DTC Sets
| • | When DTC B1544 is present, all mirror controls will be disabled. |
| • | When DTC B1600 is present, the vertical mirror control will be disabled. |
| • | When DTC B1605 is present, the horizontal mirror control will be disabled. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred. |
Diagnostic Aids
The following conditions may cause an intermittent malfunction:
| • | There is an intermittent short to ground or voltage in a mirror motor control circuit. |
| • | A mirror motor is shorted internally. |
Reference Information
Schematic Reference
Outside Rearview Mirror Schematics
Connector End View Reference
Mirror Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the appropriate outside rearview mirror C1 and C2 harness connectors.
- Ignition OFF, test for less than 1.0 ohm of resistance at each mirror motor control circuit between the outside rearview mirror C1 and C2 harness connectors and ground.
| ⇒ | If greater than the specified range, test the appropriate mirror motor control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module. |
- Connect a test lamp between mirror motor UP control circuit terminal 1 and mirror motor DOWN control circuit terminal 2 at connector C1.
- Command the appropriate mirror to the UP and DOWN positions with a scan tool. The test lamp should turn ON when commanding the Up and DOWN states.
| ⇒ | If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuit tests normal, replace the appropriate door control module. |
- Connect a test lamp between mirror motor LEFT control circuit terminal 1 and mirror motor RIGHT control circuit terminal 2 at connector C2.
- Command the appropriate mirror to the LEFT and RIGHT positions with a scan tool. The test lamp should turn ON when commanding the LEFT and RIGHT states.
| ⇒ | If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuit tests normal, replace the appropriate door control module. |
- If all circuits test normal, test or replace the appropriate mirror.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
