Hello,

Stuck on this one and was wondering if anyone might offer some insight. I have 2004 GS430 that recently got this code P0504 with the vsc, abs, and vsc off lit up on the dash, and the car won't shift out of park unless I bypass it. The rear brake lights do not turn on when pressing the brake pedal but will turn on when the lights are on. I have checked the usual suspects: replaced the brake light switch 2 times no luck, both switches I confirmed are working as I can test them on my GS400. Replaced the following fuses by driver side kick panel tail, and stop. The stop fuse was blown, and after I replaced and press the brake the fuse blows again. Disconnected taillights and the same issue with the stop fuse blowing. Tried switching out the brake lamp failure module and still stop fuse keeps blowing.

Tried to research but haven't run into anything similar to what I'm experiencing.

Out of ideas, and any help would be greatly appreciated.

 

Pay attention to checking the high-mounted stop light on the trunk spoiler. Itself or the wiring to it may be shorted.

 

Thank you for the diagram, my car does not have the spoiler.