Automatic Day-Night Mirrors Inoperative
Automatic Day-Night Mirrors Inoperative
Diagnostic Instructions
* Perform theDiagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
Circuit/System Description
The automatic day-night rear view mirror uses 2 photocell sensors that detects an increase in light. One sensor is located in the rear side of the mirror. This sensor determines the light condition present at the mirror face. The other sensor is the ambient light sensor, located on the front of the mirror or windshield side. This sensor determines the amount of light present at the mirror, When the ambient light sensor senses a low light condition and a high light condition from behind at the headlight sensor, the inside rearview mirror will automatically darken the face of the mirror.
Diagnostic Aids
The automatic day-night feature of the inside rearview mirror may mot operate properly or become inoperative due to a short to battery positive voltage in the backup lighting system.
Reference Information
Schematic Reference
Inside Rearview Mirror Schematics (Inside Rearview Mirror Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Automatic Day-Night Mirror Description and Operation (Automatic Day-Night Mirror Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)for Scan Tool Information
Circuit/System Verification
Ignition ON, place the gear shifter into the drive position, cover the ambient light sensor that faces the front windshield. Shine a flashlight into the rearview mirror face. The face of the mirror should darken.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the rearview mirror.
2. Test for less than 1 ohm of resistance between the ground circuit terminal 8 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal 9 and ground.
• If the test lamp does not illuminate, test repair the voltage supply circuit for a short to ground or an open/high resistance.
4. With the transmission in PARK, test for less than 0.5 volts between the backup lamp supply voltage circuit terminal 9 and ground.
• If the voltage is greater than the specified range, test the backup lamp supply voltage circuit for a short to voltage.
5. With the transmission in REVERSE, test for greater than 11 volts between the backup lamp supply voltage circuit and ground.
• If less than the specified range, test the backup lamp supply voltage circuit for an open/high resistance.
6. If all circuits test normal, replace the rearview mirror.
Repair Instructions
Perform theDiagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Inside Rearview Mirror Replacement (Inside Rearview Mirror Replacement)
* Control Module References (Programming and Relearning)for BCM replacement, setup, and programming.