• | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage | 2 | 2 | -- | -- |
Backup Lamp Supply Voltage | 1 | 1 | 2 | -- |
Ground | -- | 2 | 2 | -- |
1. Rearview mirror remains dimmed in reverse 2. Rearview mirror does not dim |
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.
With the gear selector lever in the REVERSE position, backup lamp supply 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.
Inside Rearview Mirror Schematics
Automatic Day-Night Mirror Description and Operation
⇒ | If the mirror face does not dim, refer to Inside Rearview Mirror Circuit Malfunction. |
⇒ | If the mirror does not transition from dim to bright, refer to Reverse Input Malfunction. |
⇒ | If the mirror face does not return to its normal state, test or replace the inside rearview mirror. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
⇒ | If less than the specified value, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Backup Lamps Inoperative . |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.