Conditions for Setting the DTC
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
B2555 01
The driver or passenger door switch detects a short to voltage in the courtesy lamp control circuit.
B2555 02
The driver or passenger door switch detects a short to ground in the courtesy lamp control circuit.