Codes 37/38, TCC Brake Switch On/Off: Notes
WARNING: This page does not describe the selected car, but rather 18 other vehicles, including the 1995 GMC Vandura Special, 1995 GMC Vandura, 1995 GMC Suburban, 1995 GMC Rally Camper Special, and 1995 GMC Rally. However, it is still accessible from the selected car via links, so may be relevant.
The normally closed brake switch supplies battery voltage to control module. Signal voltage will drop to zero volts when brake pedal is applied.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- Checks if voltage is available at brake switch.
- Checks brake switch function.
- Checks circuit from brake switch to control module.