WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance
Backup Lamp Supply Voltage
B2545
1
2
-
Backup Lamp Ground
-
1
1
-
1. Backup Lamp(s) Inoperative 2. Backup Lamp(s) Always On