• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Left Courtesy Lamp Control Circuit | B2555 00 | 1 | B2555 00 | -- |
Right Courtesy Lamp Control Circuit | B2555 00 | 1 | B2555 00 | -- |
1. Courtesy Lamps Inoperative |
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.
• | 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. |
• | DTC B2555 00 will set when the driver or passenger door switch detects a short to voltage in the courtesy lamp control circuit. |
• | DTC B2555 00 will set when the driver or passenger door switch detects a short to ground in the courtesy lamp control circuit. |
DTC B2555 00 is present, when a short to ground or short to voltage on the courtesy lamp control circuit is present.
• | 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. |
Lighting Systems Connector End Views
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for driver or passenger door switch located within the driver or passenger door module replacement, setup, and programming.