QuestionCheck engine light with code P504 and ASB light on and ESC Off lit indicating bad brake switch (brake lights do not work). I replaced the switch and checked all fuses on interior panel. All problems still exist. What should I do or check next?
AnswerHi, John.
Check the stop lamp fuse in the engine compartment fuse box. It'll be a 15A fuse, and its location should be indicated on the diagram in the cover.
If the fuse is okay, you'll need to check and see where your power seems to get lost. The first place to check, since it's convenient, is at the brake lamp switch connector.
Unplug the brake switch and check (with a test light or voltmeter) to see whether you have power in the thicker of the two blue wires. If you do, power is arriving at the switch. Next, unbolt and remove the switch and plug it into the connector. With the switch out of place, the plunger should be extended and you should now have power in the green wire. If not, the switch is defective.
If you do have power in the green wire and are still having symptoms, follow-up and I'll provide further diagnostic steps.
