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 |
|---|---|---|---|---|
Left Courtesy Lamp Control Circuit | B2555 02 | 1 | B2555 01 | -- |
Right Courtesy Lamp Control Circuit | B2555 02 | 1 | B2555 01 | -- |
1. Courtesy Lamps Inoperative | ||||
Circuit/System Description
When the body control module (BCM) signals for courtesy lamp operation, a message is sent over the GM LAN serial data circuit to the driver door and passenger door switches. The driver door switch and passenger door switch the applies battery voltage to the left and right courtesy lamp control circuits illuminating the door courtesy lamps. The driver door and passenger door switches also provide ground to the lamps.
Conditions for Running the DTC
| • | Battery voltage must be between 9-16 volts. |
| • | A message is sent from the BCM over the GM LAN serial data circuit to the driver door and passenger door switches to active the door courtesy lamps. |
Conditions for Setting the DTC
B2555 01
This DTC will set when the driver or passenger door switch detects a short to voltage in the courtesy lamp control circuit.
B2555 02
This DTC will set when the driver or passenger door switch detects a short to ground in the courtesy lamp control circuit.
Action Taken When the DTC Sets
B2555 01
When this DTC is present, the door courtesy lamps will remain illuminated.
B2555 02
When this DTC is present, the door courtesy lamps will be inoperative.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A scan tool CLEAR DTCs command is issued for that switch module. |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Disconnect the driver or passenger door harness connector C2 as applicable.
- Connect a test lamp between the courtesy lamp control circuit terminal 10 at the door harness connector and ground.
- If circuits test OK, replace the driver or passenger door switch as applicable.
| ⇒ | If the test lamp illuminates, locate and repair a short to voltage in the courtesy lamp control circuit. |
| ⇒ | If the test lamp does not illuminate, locate and repair a short to ground in the courtesy lamp control circuit. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for driver or passenger door switch replacement, setup, and programming
