P0504

Brake Light Switch Signal Correlation

Q: What does fault code P0504 mean?

Brake Light Switch Signal Correlation. The ECM has detected an inconsistency between the two signal channels of the brake light switch. Common on Toyota vehicles.

Q: What are the possible causes of P0504?

Brake light switch faulty or improperly adjusted; Brake light switch connector poor contact; Brake light bulb blown causing circuit current change.

Severity: Medium Brake System Toyota Specific

Detailed Description

The ECM has detected an inconsistency between the two signal channels of the brake light switch. Common on Toyota vehicles.

Possible Causes

Brake light switch faulty or improperly adjusted

Brake light switch connector poor contact

Brake light bulb blown causing circuit current change.

Solutions & Repair Guide

Check if the brake lights illuminate properly; Adjust the brake light switch position; Check the brake light switch connector; Replace the switch if abnormal.

Disclaimer: The information above is for reference only and does not constitute professional repair advice. Actual causes may vary depending on vehicle make, model, year, and configuration. Always consult a qualified technician for accurate diagnosis.