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 |
|---|---|---|---|---|
Dome Light Switch Signal | 2 | 2 | 2 | -- |
Left Front Door Open Switch Signal | 2 | 2 | 2 | -- |
Right Front Door Open Switch Signal | 2 | 2 | 2 | -- |
Courtesy Lamp Control | B1480 00 | 1, 2 | -- | -- |
Courtesy Lamp Low Control | 2 | 1, 2 | 1, 2 | -- |
Inside Rearview Mirror Ground | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 2 | -- | -- |
I/P Compartment Lamp Ground | -- | 2 | -- | -- |
Rear Compartment Lid Latch Assembly Ground | -- | 2 | -- | -- |
Rear Compartment Lid Pull Down Actuator Ground | -- | 2 | -- | -- |
Underhood Lamp Ground | -- | 2 | -- | -- |
Vanity Mirror Lamp-Right Ground | -- | 2 | -- | -- |
Vanity Mirror Lamp-Left Ground | -- | 2 | -- | -- |
1. Rearview Mirror Lamp(s) Inoperative - Inside 2. Courtesy Lamps Malfunction | ||||
Circuit/System Description
The CTSY/LAMP fuse supplies battery voltage to the body control module (BCM). The BCM applies battery voltage to the courtesy lamps through the courtesy lamp supply voltage circuit. When any door is opened, the jam switch contacts close and the BCM receives a door-open input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamp supply voltage circuit, providing battery voltage to all of the instrument panel (I/P) courtesy lamps, rearview mirror lamps, and rear compartment lamps. The BCM also provides a serial data message to the driver door module (DDM) and passenger door module (PDM) to apply battery voltage to the exterior courtesy lamps.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the inside rearview mirror.
- Ignition OFF, scan tool OFF, interior lamps OFF, test for less than 1 ohm between the ground circuit terminal 8 and ground.
- Ignition OFF, test for less than 1 ohm between the control circuit terminal 1 and ground.
- Ignition ON, verify that a test lamp illuminates between the control circuit terminal 6 and ground.
- If all circuits test normal, replace the inside rearview mirror.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
