DTC P0719: Brake Switch Circuit - Low Input (4L80-E A/T): Description
WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Sierra, 2002 GMC Savana Special, 2002 GMC Savana Camper Special, and 2002 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.
The TCC/Stoplamp switch indicates the brake pedal status. The normally-closed TCC/Stoplamp switch supplies a battery voltage signal to the Powertrain Control Module (PCM). The signal voltage circuit opens when the brake pedal is applied. If the PCM detects an open TCC/Stoplamp switch circuit during accelerations, then DTC P0719 sets.