P0504 — Brake Switch Correlation Error
| Meaning | The engine computer has noticed a disagreement between the two internal sensors inside your brake pedal switch. One sensor says you are pressing the brake pedal, while the other sensor says you are not. Because the system cannot verify what your foot is doing, it flags this fault. |
| Family | Powertrain (P) |
Typical symptoms
The check engine light is illuminated on the dashboard
Sometimes the brake lights stay on or fail to light up when pressing the pedal
Common causes
Corroded or loose electrical connector at the brake switch
Blown fuses or wiring issues related to the brake light circuit
What to do
Frequently asked questions
What does code P0504 mean?
Brake Switch Correlation Error. The engine computer has noticed a disagreement between the two internal sensors inside your brake pedal switch. One sensor says you are pressing the brake pedal, while the other sensor says you are not. Because the system cannot verify what your foot is doing, it flags this fault.
Can I keep driving with code P0504 active?
With caution: limp mode possible, have it checked soon
Common causes — P0504
Faulty or misadjusted brake pedal position switch Corroded or loose electrical connector at the brake switch Blown fuses or wiring issues related to the brake light circuit
How do you fix code P0504?
You should check the brake pedal switch and its wiring connector first. It is wise to inspect this soon, as a failing brake switch can affect important safety features like cruise control and your brake lights.
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