WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
DTC B1433
Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance
Run Relay Coil Control
B1433 00
1
-
-
1. No power at multiple fuses in the RUN position.