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 Circuit Short to Battery or OpenDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Courtesy Lamp High Control | 1 | 1 | 1 | -- |
Courtesy Lamp Low Control | 1 | B2555 05 | B2555 05 | -- |
Dome/Reading Lamps Ground | -- | 1 | -- | -- |
Overhead Console Courtesy Lamp Ground | -- | 1 | -- | -- |
Rear Compartment Courtesy Lamp Ground | -- | 4 | -- | -- |
Vanity Mirror Courtesy Lamp - Right Ground | -- | 3 | -- | -- |
Vanity Mirror Courtesy Lamp - Left Ground | -- | 3 | -- | -- |
1. Courtesy Lamps Malfunction 2. Dome Lamps Malfunction 3. Vanity Mirror Lamps Malfunction 4. Rear Compartment Lamp Malfunction | ||||
Circuit/System Description
The body control module (BCM) applies battery voltage to the courtesy lamps through the courtesy lamps high control circuit. When any door is opened, the door ajar 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 high control circuit, providing battery voltage to all of the dome lamps, reading lamps, rear compartment lamp, and vanity mirror lamps. The dome lamps switch consists of 3 positions, ON, DOOR, and OFF. When the dome lamp switch is placed in the DOOR position, the dome lamps will illuminate when a door is opened. The dome lamps are provided with battery voltage via the courtesy lamps high control circuit and ground through the courtesy lamps low control circuit. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp high control circuit to prevent a total battery discharge condition.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
DTC B2555 05 will set when the BCM detects a short to voltage or an open in the courtesy lamp low control circuit.
Action Taken When the DTC Sets
When the DTC is present, the dome lamps will not illuminate when a door is opened.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 100 consecutive malfunction-free 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, disconnect the harness connector at the appropriate dome/courtesy lamp assembly.
- Connect a test lamp between B+ and the appropriate control circuit terminal listed below.
- 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 all circuits test normal, replace the inoperative courtesy/reading lamp assembly.
| • | Dome/reading lamps control terminal B |
| • | Overhead console courtesy/reading lamps control terminal C - with C95 |
| ⇒ | If the test lamp is always OFF, 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 is always ON, test the control circuit for a short to ground. 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 |
