Brake Pedal Position Sensor Circuit Failure
The brake pedal position sensor is not providing a valid signal.
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 tells the vehicle's computer how far the brake pedal is pressed. If it fails, the computer won't know if you're braking, which can cause issues with brake lights and ABS operation.
What the computer is actually seeing
The computer expects a variable voltage signal from the brake pedal position sensor, typically ranging from 0.5 volts (pedal not pressed) to 4.5 volts (pedal fully pressed).
What a healthy reading looks like
0.5V to 4.5V depending on pedal position; ideally linear with position.
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 pedal position sensor wiring for any visible damage or corrosion. Decide: Is the wiring intact? Yes: Go to step 2. No: Repair or replace wiring and retest.
- 22. Check the connector at the brake pedal position sensor for loose connections or corrosion. Decide: Is the connector clean and securely attached? Yes: Go to step 3. No: Clean or repair the connector and retest.
- 33. Using a multimeter, measure the output voltage at the brake pedal position sensor while varying the pedal position. Expected range should be 0.5V to 4.5V. Decide: Is the voltage within expected values? Yes: Replace the brake pedal position sensor. No: Check the sensor further or inspect the brake system.
Common causes
- Faulty brake pedal position sensor
- Wiring issues or connector problems
- Corroded or damaged brake pedal assembly
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Driving is possible but not recommended as it can affect braking systems and ABS operation.
Will this code come back after resetting?
If the underlying issue is not fixed, the code will likely return.
Why does this code appear with C1518?
C1518 indicates that the brake system is detecting a malfunction in the brake sensor circuit, which can be related.
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