Brake Switch Circuit 1 Failure
The brake switch signal is not functioning properly.
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 is supposed to tell the vehicle's computer when you're pressing the brake pedal. If it fails, the computer can't figure out what to do when you stop, which can cause problems with the brakes and other systems.
What the computer is actually seeing
The vehicle's computer expects a signal from the brake switch to go from 0 volts (off) to around 12 volts (on) when the brake pedal is pressed. If it stays at 0 volts or fluctuates unexpectedly, it triggers this fault code.
What a healthy reading looks like
Brake switch signal should switch from 0 volts to at least 11-12 volts when the brake pedal is 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. Check the brake switch for visible damage or wear.
- 22. Measure voltage at the brake switch connector with the brake pedal unpressed. Expect 0 volts.
- 33. Press the brake pedal and measure voltage again. It should increase to around 11-12 volts.
- 44. If you don't see the expected voltage change, replace the brake switch and retest.
- 55. If voltage is still off after replacing the switch, inspect wiring and connectors for short circuits or opens.
- 66. If wiring looks good, check for a solid ground connection at the switch.
Common causes
- Faulty brake switch
- Wiring issues (open or short circuits)
- Connector corrosion or damage
- Multiple brake switch failures in tandem
- Poor ground connection
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's moderate severity; drive cautiously and fix soon as brake function may be compromised.
Will this code come back after clearing?
If the underlying issue isn’t resolved, yes, it will return.
Why does this code appear with other codes?
Other codes may relate to brake or safety systems that depend on the brake switch functionality.
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