Circuit/System Verification

WARNING: This page is about a different car, the 2023 GMC Sierra 3500 HD and 2023 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Ignition - On/Vehicle - In Service Mode
Verify the scan tool parameter: Brake Pedal Applied = Inactive
- If not the specified state
- Refer to: Stop Lamps Malfunction (Regular Cab) , or Stop Lamps Malfunction (Extended Cab)
- Go to next step: If the specified state
Operate the component: Brake Pedal - Pressed
Operate the component: S3 Transmission Shift Lever - Park & Drive
- If not the specified state
  Refer to: Circuit/System Testing
- Go to next step: If the specified state
All OK.