Brake Pedal Position Sensor 1 Performance
The brake pedal position sensor signal is out of range or not responding correctly.
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 pedal position sensor measures how far down you push the brake pedal. If it's acting up, the car won't know if you're trying to stop, making brakes unreliable.
What the computer is actually seeing
The engine control module (ECM) expects a variable voltage from the sensor, typically 0.5 to 4.5 volts based on pedal position. If it sees a voltage that's too high or low, it triggers this code.
What a healthy reading looks like
0.5V (pedal up) to about 4.5V (pedal fully down) under normal conditions.
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 wiring and connectors at the brake pedal position sensor for any signs of damage or corrosion. Repair as necessary. Decision: If you observe damage, fix it and retest.
- 22. Measure the voltage output of the brake pedal position sensor. Wiggle the connector while testing to check for intermittent faults. Decision: If voltage is outside of 0.5V to 4.5V when the pedal is operated, the sensor is likely faulty.
- 33. Check the brake fluid level and condition in the master cylinder. Low or contaminated fluid can affect the sensor. Decision: If fluid is low, top it off, or if contaminated, replace it and retest.
- 44. If previous checks are good, replace the brake pedal position sensor. Decision: Clear the fault code and take the vehicle for a test drive to confirm if the issue persists.
Common causes
- Faulty brake pedal position sensor
- Wiring issues or broken connections
- Corrosion at sensor connector
- Brake fluid contamination affecting sensor function
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Not recommended. Brakes may not respond as expected.
Will the code come back after repairs?
If the sensor and wiring are fixed correctly, it should not return.
Why does this code sometimes pair with other codes?
It can indicate related issues with brake systems, like ignition or traction control.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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