Brake Switch Circuit Malfunction
There’s a fault in the brake switch circuit.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The brake switch tells the computer if you’re pressing the brake. If it fails, the truck doesn’t know if you want to stop.
What the computer is actually seeing
The computer is monitoring the voltage signal from the brake switch, expecting a change when the brake pedal is pressed or released.
What a healthy reading looks like
Voltage should be 0V when not pressed and close to battery voltage (around 12V) when pressed.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the brake switch and wiring for damage or disconnection.
- 22. Check connector pins for corrosion or bent pins.
- 33. Test the brake switch operation by measuring voltage at the switch: should be 0V off and ~12V on.
- 44. If there's no voltage change, replace the brake switch and retest.
- 55. If the problem persists, check wiring continuity from the switch to the BCM.
Common causes
- Faulty brake switch
- Wiring issues or shorts
- Corroded connectors
- Fault in the BCM (Body Control Module)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; you might have problems with brake lights not functioning. Fix it soon.
Will this code come back after clearing?
If the underlying issue isn’t fixed, the code will likely return.
Why does it pair with C0220?
C0220 is often a related issue indicating the circuit is open or shorted.
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