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
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Inside Rearview Mirror Accessory/Run Voltage Circuit | 1 | 1 | -- | -- |
Inside Rearview Mirror Ground Circuit | -- | 1 | 1 | -- |
Backup Lamp Supply Voltage Circuit | 1 | 1 | 1 | -- |
1 Auto Day-Night Rearview Mirror Inoperative | ||||
Circuit/System Description
The automatic day-night rearview 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 not operate properly or become inoperative due to a short to battery positive voltage in the backup lighting system.
Reference Information
Schematic Reference
Connector End View Reference
Master Electrical Component List
Electrical Information Reference
Circuit/System Verification
Ignition ON, turn ON the automatic day-night feature of the rearview mirror. A green indicator light will be ON when automatic dimming is ON. Place the gear shiftier 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
- Ignition OFF, disconnect the harness connector at the rearview mirror terminals 9 and 13.
- Test for less than 3 ohm of resistance between the ground circuit terminal 8 and ground.
- Ignition ON, verify that a test lamp illuminates between the voltage supply circuit terminal 9 and ground.
- With the transmission in PARK, test for 0.5 volt between the backup lamp supply voltage circuit terminal 9 and ground.
- With the transmission in REVERSE, test for battery voltage between the backup lamp supply voltage circuit terminal 9 and ground.
- If all circuits test normal, replace the rearview mirror.
| ⇒ | If greater than the specified value, test the ground circuit terminal 8 for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, repair the voltage supply circuit terminal 9 for a short to ground or an open/high resistance. |
| ⇒ | If the voltage is greater than 0.6 volt, test the backup lamp supply voltage circuit terminal 9 or a short to voltage. |
| ⇒ | If the voltage is less than specified voltage, test the backup lamp supply voltage circuit terminal 9 for an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
