Automatic Day-Night Mirrors Malfunction
Automatic Day-Night Mirrors Malfunction
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
Diagnostic Fault Information
Circuit/System Description
The inside rearview mirror uses 2 photocell sensors. One sensor is the rear light sensor, located on the face side of the mirror, facing the rear of the vehicle. The rear light sensor is used to determine light conditions present at the mirror face. The other sensor is the front light sensor, located on the backside of the mirror, facing the front of the vehicle. The front light sensor is used to determine the exterior light conditions at the front of the vehicle. With a low exterior light condition detected by the front light sensor and a high light condition from the rear light sensor, the inside rearview mirror will automatically darken the face of the inside rearview mirror and the driver outside rearview mirror. The inside rearview mirror provides a signal circuit and a low reference circuit to the driver mirror face to darken the mirror when needed.
With the gear selector lever in the REVERSE position and the engine running, backup lamp control voltage is supplied as an input to the inside rearview mirror. The mirror monitors this input to disable the automatic day-night feature. This allows the driver to see objects in the mirror clearly when backing up, regardless of the rear light sensor status.
Reference Information
Schematic Reference
* Inside Rearview Mirror Schematics Inside Rearview Mirror Schematics
* Outside Rearview Mirror Schematics Outside Rearview Mirror Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left
Description and Operation
Automatic Day-Night Mirror Description and Operation Automatic Day-Night Mirror
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 Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Cover the windshield with a blanket or other suitable item.
3. Verify the A10 Inside Rearview Mirror face dims when shining a bright light into the rear light sensor
• If the A10 Inside Rearview Mirror does not dim
Refer to Circuit/System Testing - Inside Review Mirror Dimming Inoperative
• If the A10 Inside Rearview Mirror dims
4. Verify the A10 Inside Rearview Mirror face transitions from dim to bright while commanding the Backup Lamps Active and Inactive with a scan tool.
• If the A10 Inside Rearview Mirror does not transition between dim and bright.
Refer to Circuit/System Testing - Day-Night Disable Malfunction
• If the A10 Inside Rearview Mirror transitions between bright and dim states
5. Verify the A9A Outside Rearview Mirror-Driver face dims when shining a bright light into the rear light sensor.
• If the A9A Outside Rearview Mirror-Driver does not dim
Refer to Outside Rearview Mirror Dimming Malfunction.
• If the A9A Outside Rearview Mirror-Driver dims
6. Verify the A9A Outside Rearview Mirror-Driver face transitions from dim to bright while commanding the Backup Lamps Active and Inactive with a scan tool.
• If the A9A Outside Rearview Mirror-Driver does not transition between bright and dim states
Refer to Outside Rearview Mirror Dimming Malfunction.
• If the A9A Outside Rearview Mirror-Driver transitions between bright and dim states
7. All OK.
Circuit/System Testing
Inside Review Mirror Dimming Inoperative
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A10 Inside Rearview Mirror. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 5 and ground.
• If 10 ohms or greater
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the ignition circuit terminal 2 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, 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, remove the test lamp.
2. Test for infinite resistance between the ignition circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the A10 Inside Rearview Mirror
• If the test lamp illuminates
5. Replace the A10 Inside Rearview Mirror.
Day-Night Disable Malfunction
1. Ignition OFF, disconnect the harness connector at the A10 Inside Rearview Mirror. Ignition ON
2. Connect a test lamp between the control circuit terminal 1 and ground
3. Verify the test lamp turns ON and OFF while commanding the Backup Lamps Active and Inactive with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit terminal 1 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, refer to Backup Lamps Malfunction (Automatic Transmission) Backup Lamps Malfunction (Automatic Transmission)Backup Lamps Malfunction (Manual Transmission) Backup Lamps Malfunction (Manual Transmission).
• If the test lamp is always ON
1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, refer to Backup Lamps Malfunction (Automatic Transmission) Backup Lamps Malfunction (Automatic Transmission)Backup Lamps Malfunction (Manual Transmission) Backup Lamps Malfunction (Manual Transmission)
• If the test lamp turns ON and OFF
4. Replace the A10 Inside Rearview Mirror.
Outside Rearview Mirror Dimming Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the A9A Outside Rearview Mirror-Driver. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the low reference circuit terminal 16 and ground.
• If 10 ohms or greater
1. Ignition OFF, disconnect the harness connector at the A10 Inside Rearview Mirror.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the A10 Inside Rearview Mirror.
• If less than 10 ohms
3. Ignition ON.
4. Test for less than 1 V between the control circuit terminal 2 and ground.
• If 1 V or greater
1. Ignition OFF, disconnect the harness connector at the A10 Inside Rearview Mirror, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V replace the A10 Inside Rearview Mirror.
• If less than 1 V
5. Ignition ON, headlamps ON, vehicle in PARK, cover the front light sensor with a towel or other suitable item. Shine a flashlight at the rear light sensor.
6. Test for greater than 1 V between the control circuit terminal 2 and ground.
• If 1 V or less
1. Ignition OFF, disconnect the harness connector at the A10 Inside Rearview Mirror, ignition ON.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, test or replace the A10 Inside Rearview Mirror.
• If greater than 1 V
7. Test or replace A9A Outside Rearview Mirror-Driver.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Inside Rearview Mirror Replacement Inside Rearview Mirror Replacement
* Outside Rearview Mirror Glass Replacement Outside Rearview Mirror Glass Replacement