Diagnostic Instructions
Circuit/System Description
When a courtesy lamp request is seen, ignition voltage is supplied to each of the courtesy lamps by the body control module (BCM) via the courtesy lamp supply voltage circuit. The courtesy lamp supply voltage circuit controls the following lamps:
| • | I/P Courtesy Lamp -- Left and Right |
| • | Roof Rail Courtesy Lamp -- Left and Right (w/o TR9/CF5) |
| • | Roof Rail Courtesy/Reading Lamp -- Left and Right (w/ TR9/CF5) |
| • | Dome Lamp (w/o TR9/CF5) |
Reference Information
Schematic Reference
Interior Lights Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
Ignition ON, command the Interior Lamps ON and OFF with a scan tool. The courtesy lamps should turn ON and OFF when changing between the commanded states.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate courtesy lamp.
- Test for less than 10 ohms of resistance between the appropriate ground circuit terminal and ground:
| • | I/P Courtesy Lamp -- Terminal B |
| • | Roof Rail Courtesy Lamp (w/o TR9/CF5) -- Terminal A |
| • | Roof Rail Courtesy/Reading Lamp (w/ TR9/CF5) -- Terminal A |
| • | Dome Lamp (w/o TR9/CF5) -- Terminal D |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Connect a test lamp between the appropriate control circuit terminal and ground:
| • | I/P Courtesy Lamp -- Terminal A |
| • | Roof Rail Courtesy Lamp (w/o TR9/CF5) -- Terminal B |
| • | Roof Rail Courtesy/Reading Lamp (w/ TR9/CF5) -- Terminal B |
| • | Dome Lamp (w/o TR9/CF5) -- Terminal B |
- Ignition ON, command the Interior Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an
open/high resistance. If the circuit tests normal, replace the BCM. |
- If all circuits test normal, test or replace the appropriate courtesy lamp bulb.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
