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. |
DTC Descriptor
DTC B2555 05: Passenger Compartment Lamp Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Courtesy Lamp Control Circuit | B2555 00 | 2 | 1 | -- |
Inadvertent Power Courtesy Lamps | B1480 00, 3 | 2 | -- | -- |
Overhead Ground | -- | 2 | -- | -- |
1. Overhead Console Lamp Always On 2. Overhead Console Lamp Malfunction 3. Inadvertent Power Courtesy Lamps Malfunction | ||||
Circuit/System Description
The CTSY/RF TRN fuse supplies battery voltage to the body control module (BCM). When the BCM commands the courtesy lamps ON, it applies battery voltage through the courtesy lamp relay control circuit to the coil side of the OVRHD LAMPS Relay, energizing the relay. Battery voltage from the inadvertent power courtesy lamp circuit is applied through the switch side of the relay and the courtesy lamp supply voltage circuit to the overhead console lamp, illuminating the courtesy lamp. The BCM also applies battery voltage through the courtesy lamp supply voltage circuit to the left and right roof rail courtesy lamps and the front, middle, and rear door courtesy lamps. When any door is opened, the door open switch contacts close and the BCM receives a door-open input and it will illuminate the courtesy lamps. If the BCM receives a door lock or unlock input or a rear hatch open input, it will illuminate the courtesy lamps.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The BCM detects a short to voltage in the courtesy lamp relay control circuit.
Action Taken When the DTC Sets
The BCM will deactivate the overhead lamps relay for the remainder of the ignition cycle.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 100 consecutive malfunction ignition cycles have occurred. |
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, remove the OVRHD LAMPS Relay from the rear fuse block.
- Connect a test lamp between the control circuit terminal 4 and ground.
- Ignition ON, command the Courtesy Lamp ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If the circuit tests normal, test or replace the overhead lamp relay.
| ⇒ | 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. |
Component Testing
Relay Test
- Ignition OFF, disconnect the relay.
- Test for 70-100 ohms between terminals 85 and 86.
- Test for infinite resistance between the following terminals:
- Install a 10A fused jumper wire between relay terminal 85 and B+. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.
| ⇒ | If the resistance is not within the specified range, replace the relay. |
| • | 30 and 85 |
| • | 30 and 86 |
| • | 30 and 87 |
| • | 85 and 87 |
| ⇒ | If not the specified value, replace the relay. |
| ⇒ | If greater than the specified range, replace the relay. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
