Conditions for Setting the DTC

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The vehicle speed decreases by at least 4.2 km/h (2.6 mph) within 0.25 seconds.
The PCM detects a TCC brake transition.
The PCM does not detect a stop lamp switch transition.