P0504
Brake Light Switch Signal Correlation
Detailed Description
The ECM has detected an inconsistency between the two signal channels of the brake light switch.
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.