Buick Regal: Power Mirror Tilt Inoperative in Reverse

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The outside mirror switch and passenger window switch are on a serial data circuit with the memory seat module as the master. The mirror select and directional control switches are inputs to the memory seat module through the serial data circuit. When the memory seat module receives switch inputs from the outside mirror switch, mirror output commands are sent to the appropriate switch through the serial data circuit. The outside mirror switch and passenger window switch control the left and right outside rear view mirrors through bi-directional motor control circuits. The motor control circuits are floating while in an inactive state and the switches will apply power and ground to the control circuits as necessary to move the mirror in the commanded direction.

Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The outside mirror switch and passenger window switch supply a 5 V reference, low reference, and horizontal and vertical position signal circuits to these sensors. The signal circuits are referenced from 5 V by the switches and the signal circuit voltage levels represent the mirror positions. The mirror positions are sent to the memory seat module through the serial data circuit where they are stored for memory mirror operation. When the memory seat module receives a memory recall command, the memory seat module will send the go to position commands to the outside mirror switch and passenger window switch. The switches will then drive the appropriate mirror motors to the commanded position sensor settings.

Diagnostic Aids

The Park Tilt Mirror in Reverse is a feature in the Personalization Menu of the audio system controls that allows the operator to program the driver and/or passenger outside rearview mirrors to tilt downward when the vehicle is shifted into R (reverse). Verify that this feature has been correctly programmed into the system before performing extensive diagnostics

Reference Information

Schematic Reference

Outside Rearview Mirror Wiring Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

Outside Mirror Description and Operation (With A45)Outside Mirror Description and Operation (Without A45)

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

1. Ignition ON.

2. Verify the A9A Outside Rearview Mirror - Driver moves when commanding the Driver Mirror Horizontal Movement Right/Left and Driver Mirror Vertical Movement Up/Down with a scan tool.

• If the A9A Outside Rearview Mirror - Driver does not move RIGHT or LEFT or UP or DOWN

Refer to Power Mirror Malfunction (With A45)Power Mirror Malfunction (Without A45).

• Go to next step: If the A9A Outside Rearview Mirror - Driver moves RIGHT, LEFT, UP and DOWN

3. Verify the A9B Outside Rearview Mirror-Passenger moves when commanding the Passenger Mirror Horizontal Movement Right/Left and Passenger Mirror Vertical Movement Up/Down with a scan tool.

• If the A9B Outside Rearview Mirror-Passenger does not move RIGHT or LEFT or UP or DOWN

Refer to Power Mirror Malfunction (With A45)Power Mirror Malfunction (Without A45).

• Go to next step: If the A9B Outside Rearview Mirror-Passenger moves RIGHT, LEFT, UP and DOWN

4. All OK.

Circuit/System Testing

1. Engine running, shift the vehicle in REVERSE.

2. Verify that the appropriate A9 Outside Rearview Mirror moves DOWN.

• If the A9 Outside Rearview Mirror does not move DOWN

Replace the K40 Seat Memory Control Module

• Go to next step: If the A9 Outside Rearview Mirror does move DOWN

3. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for the seat memory control module replacement, programming and setup.

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