Brake Switch Circuit Test

2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6SECTION Brake Switch Circuit Test
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the stop lamp switch.
  2. Ignition ON, test for B+ between the ignition supply circuit terminal B and ground.
    • If less than the specified range, test the ignition supply circuit for a short to ground or an open/high resistance.
  3. Verify the scan tool TCM Brake Switch parameter is Released.
    • If not the specified value, test the signal circuit terminal A for a short to voltage.
  4. Install a 3A fused jumper wire between the signal circuit terminal B and the ignition supply circuit terminal A. Verify the scan tool Brake Switch parameter is Applied.
    • If not the specified value, test the signal circuit for an open/high resistance.
  5. If all circuits test normal, test or replace the stop lamp switch.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.