Brake Switch A Circuit High Input
The brake switch signal is too high for the expected range.
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 computer is getting an unexpected high signal from the brake pedal switch, which tells it that the brake is always pressed.
What the computer is actually seeing
The brake switch normally outputs around 0.5V when not pressed and 4.5V when pressed. A signal over 4.5V indicates a stuck switch or wiring issue.
What a healthy reading looks like
Brake switch voltage should range from 0.5V (not pressed) to 4.5V (fully 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 brake switch operation. Disconnect the switch and measure voltage between the connector terminal and ground. It should be below 4.5V when the pedal is not pressed.
- 22. Inspect connectors and wiring leading to the brake switch for any signs of damage, corrosion, or shorts. Repair as necessary.
- 33. If the wiring and connectors are good, replace the brake switch and retest the system.
Common causes
- Stuck brake pedal switch
- Faulty wiring or connectors
- Corroded terminals
- Brake pedal incorrectly adjusted
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may not be safe since it affects brake functionality; fix it as soon as possible.
Will this code come back after clearing?
If the issue isn't resolved (faulty switch or wiring), it will return.
Why does this code sometimes pair with others?
Multiple related codes can indicate a common issue, like circuit problems affecting several systems.
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