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 Descriptors
DTC B2555 01 : Passenger Compartment Lamp Control Circuit Short to BatteryDTC B2555 02: Passenger Compartment Lamp Control Circuit Short to Ground
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Courtesy Lamp High Control - Driver Door | B2555 02 | 1 | B2555 01 | -- |
Courtesy Lamp High Control - Passenger Door | B2555 02 | 1 | B2555 01 | -- |
Courtesy Lamp Supply Voltage | 1 | 1 | -- | -- |
Dome Lamp Switch Signal | 2 | 2 | 2 | -- |
Inadvertent Power Supply Voltage | 1 | 1 | 1 | -- |
Left Front Door Open Switch Signal | 3 | 3 | 3 | -- |
Left Rear Door Open Switch Signal | 3 | 3 | 3 | -- |
Right Front Door Open Switch Signal | 3 | 3 | 3 | -- |
Right Rear Door Open Switch Signal | 3 | 3 | 3 | -- |
Courtesy Lamp Low Control - Driver Door | -- | 1 | -- | -- |
Courtesy Lamp Low Control - Passenger Door | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 2 | -- | -- |
LH Vanity Mirror Courtesy Lamp Ground | -- | 1 | -- | -- |
Liftgate Courtesy Lamp Ground | -- | 1 | -- | -- |
Overhead Console Courtesy Lamp Ground | -- | 1 | -- | -- |
Rear Dome Lamp Ground | -- | 1 | -- | -- |
RH Vanity Mirror Courtesy Lamp Ground | -- | 1 | -- | -- |
| ||||
Circuit/System Description
The BCM 3 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, dome lamps, rearview mirror lamps, and rear compartment lamps. The BCM also provides a GMLAN serial data message to the driver door module (DDM) and front passenger door module (PDM) to apply battery voltage to the door courtesy lamps. 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 inadvertent power courtesy lamp control circuit to prevent a total battery discharge condition. For more detailed information concerning courtesy lamp operation refer to Interior Lighting Systems Description and Operation .
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B2555 01
The DTC will set when the DDM or PDM detects a short to voltage in the courtesy lamp High control circuit.
B2555 02
The DTC will set when the DDM or PDM detects a short to ground in the courtesy lamp High control circuit.
Actions Taken When the DTC Sets
B2555 01
When the DTC is present, the affected door courtesy lamp will remain illuminated.
B2555 02
When the DTC is present, the affected door courtesy lamp will not illuminate.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Diagnostic Aids
After clearing the DTC, the ignition has to be cycled ON and OFF before the inoperative courtesy lamp will operate.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate door courtesy lamp.
- Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 ohms of resistance between the low control circuit and ground.
- Connect a test lamp between the high control circuit and the low control circuit.
- Command the puddle/courtesy lamp 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, test or replace the appropriate door courtesy lamp.
| ⇒ | If greater than the specified range, test the low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module. |
| ⇒ | If the test lamp is always ON, test the high control circuit for a short to voltage. If the circuit tests normal, replace the appropriate door control module. |
| ⇒ | If the test lamp is always OFF, test the high control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the appropriate door control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for DDM or PDM replacement, setup, and programming
