Buick Regal: Power Mirror Malfunction (without A45)

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

Diagnostic Fault Information

1. Both Outside Power Mirrors Inoperative
2. Driver Outside Power Mirror Malfunction
3. Passenger Outside Power Mirror Malfunction

Circuit/System Description

The outside rearview mirror switch controls the outside rearview mirrors based on the position of the mirror selector switch and which movement position is selected. The outside rearview mirror switch has four positions: up, down, left, and right. B+ is applied to the switch from the power mirror fuse and when a movement position switch is selected, voltage is sent to the commanded mirror via a mirror control circuit. The opposite mirror control circuit acts as a ground circuit for the bi-directional mirror motor. Ground is the applied through the switch.

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 (Without A45)

Electrical Information Reference

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

Circuit/System Verification

1. Verify the mirror glass of the A9A Outside Rearview Mirror-Driver and the A9B Outside Rearview Mirror-Passenger move UP, DOWN, LEFT and RIGHT with the S146 Outside Rearview Mirror Switch.

• If both outside mirror glasses do not move

Refer to Circuit/System Testing - Both Outside Rearview Mirrors Inoperative.

• If the driver outside mirror glass does not move UP, DOWN, LEFT or RIGHT

Refer to Circuit/System Testing - Driver Outside Mirror Movement Malfunction.

• If the passenger outside mirror glass does not move UP, DOWN, LEFT or RIGHT

Refer to Circuit/System Testing - Passenger Outside Mirror Movement Malfunction.

• Go to next step: If the mirror glass of the A9A Outside Rearview Mirror-Driver and the A9B Outside Rearview Mirror-Passenger move UP, DOWN, LEFT and RIGHT

2. All OK.

Circuit/System Testing

Both Outside Rearview Mirrors Inoperative

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S146 Outside Rearview Mirror Switch. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 Ω between the ground circuit terminal 24 and ground.

• If 10 Ω or greater

1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, repair the open/high resistance in the ground connection.

• Go to next step: If less than 10 Ω

3. Verify a test lamp illuminates between the B+ circuit terminal 23 and ground.

• If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF.
2. Test for less than 2 Ω in the B+ circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.

• If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for infinite resistance between each of the control circuit terminals listed below and ground:
   • Control circuit terminal 2
   • Control circuit terminal 3
   • Control circuit terminal 4
   • Control circuit terminal 6
   • Control circuit terminal 7
   • Control circuit terminal 8
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the appropriate M77 Outside Rearview Mirror Motor.

• Go to next step: If the test lamp illuminates

4. Test or replace the S146 Outside Rearview Mirror Switch.

Driver Outside Mirror Movement Malfunction

1. Ignition OFF, disconnect the X510 inline harness connector at the A9A Outside Rearview Mirror- Driver. Ignition ON 2. Connect a test lamp between the control circuit terminal 9 and control circuit terminal 12.

3. Verify the test lamp turns ON when commanding the UP and DOWN states with the S146 Outside Rearview Mirror Switch.

• If the test lamp remains OFF during either of the commands

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch.
2. Test for infinite resistance between each control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, test or replace the S146 Outside Rearview Mirror Switch.

• If the test lamp is always ON

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch, ignition ON.
2. Test for less than 1 V between each control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, test or replace the S146 Outside Rearview Mirror Switch

• Go to next step: If the test lamp turns ON during each of the commands

4. Connect a test lamp between the control circuit terminal 10 and control circuit terminal 12.

5. Verify the test lamp turns ON when commanding the LEFT and RIGHT states with the S146 Outside Rearview Mirror Switch.

• If the test lamp remains OFF during either of the commands

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch.
2. Test for infinite resistance between each control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, test or replace the S146 Outside Rearview Mirror Switch.

• If the test lamp is always ON

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch, ignition ON.
2. Test for less than 1 V between each control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, test or replace the S146 Outside Rearview Mirror Switch

• Go to next step: If the test lamp turns ON during each of the commands

6. Test or replace the M77D Outside Rearview Mirror Motor-Driver.

Passenger Outside Mirror Movement Malfunction

1. Ignition OFF, disconnect the X610 inline harness connector at the A9B Outside Rearview Mirror- Passenger. Ignition ON 2. Connect a test lamp between the control circuit terminal 9 and control circuit terminal 12.

3. Verify the test lamp turns ON when commanding the UP and DOWN states with the S146 Outside Rearview Mirror Switch.

• If the test lamp remains OFF during either of the commands

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch.
2. Test for infinite resistance between each control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, test or replace the S146 Outside Rearview Mirror Switch.

• If the test lamp is always ON

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch, ignition ON.
2. Test for less than 1 V between each control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, test or replace the S146 Outside Rearview Mirror Switch

• Go to next step: If the test lamp turns ON during each of the commands

4. Connect a test lamp between the control circuit terminal 10 and control circuit terminal 12.

5. Verify the test lamp turns ON when commanding the LEFT and RIGHT states with the S146 Outside Rearview Mirror Switch.

• If the test lamp remains OFF during either of the commands

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch.
2. Test for infinite resistance between each control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in each control circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, test or replace the S146 Outside Rearview Mirror Switch.

• If the test lamp is always ON

1. Ignition OFF, remove the test lamp, disconnect the harness connector at the S146 Outside Rearview Mirror Switch, ignition ON.
2. Test for less than 1 V between each control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, test or replace the S146 Outside Rearview Mirror Switch

• Go to next step: If the test lamp turns ON during each of the commands

6. Test or replace the M77P Outside Rearview Mirror Motor-Passenger.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Outside Rearview Mirror Actuator Replacement
• Front Side Door Window Switch Replacement

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