So I have had the engine lite on for a while now, it is always code P0504, brake switch error. It used to just happen at random times, but became became pretty constant.
At that point I checked for the usual problems. All the brake lites work, fuse is good (obviously if the lites work), no obvious chewed/frayed wires. So I replaced the stop lite switch. Well the problem persists. I can clear the code but it comes back, usually within 10 miles of driving.
Have read the service manual, and it would seem the next step might be to go to a dealer and have them read the detailed diagnostics on why this code is popping up; e.g. which circuits are not comparing properly to which. Can do this, but it will no doubt be costly. So I thought I would ask here for advise first.
When I look at the details of the recorded P0504s on my code reader, they all seem to happen at 0mph at idle rpm. So I am guessing it is something about stopping at a lite that is triggering the fault. Perhaps I have a bad stop switch, or I fumbled something during the reinstall, or the pedal is traveling further now.
I have another aftermarket switch I will install again, but wanted to check here as the proper procedure for installing this switch. Beyond the obvious of taking the old one out and putting the new one in with the wire connector, there is that lever on the top of the switch which is supposed to be turned after install. Any tricks or details that are important here? I have been assuming that one should pump the brake pedal a few times to "set" full travel on the switch before flipping that lever; is that right?
Otherwise, anyone else run into a similar problem, what other things could be causing a P0504 when everything seems to be working???
At that point I checked for the usual problems. All the brake lites work, fuse is good (obviously if the lites work), no obvious chewed/frayed wires. So I replaced the stop lite switch. Well the problem persists. I can clear the code but it comes back, usually within 10 miles of driving.
Have read the service manual, and it would seem the next step might be to go to a dealer and have them read the detailed diagnostics on why this code is popping up; e.g. which circuits are not comparing properly to which. Can do this, but it will no doubt be costly. So I thought I would ask here for advise first.
When I look at the details of the recorded P0504s on my code reader, they all seem to happen at 0mph at idle rpm. So I am guessing it is something about stopping at a lite that is triggering the fault. Perhaps I have a bad stop switch, or I fumbled something during the reinstall, or the pedal is traveling further now.
I have another aftermarket switch I will install again, but wanted to check here as the proper procedure for installing this switch. Beyond the obvious of taking the old one out and putting the new one in with the wire connector, there is that lever on the top of the switch which is supposed to be turned after install. Any tricks or details that are important here? I have been assuming that one should pump the brake pedal a few times to "set" full travel on the switch before flipping that lever; is that right?
Otherwise, anyone else run into a similar problem, what other things could be causing a P0504 when everything seems to be working???
![5231321 1[3]](/data/xfmg/thumbnail/3/3526-3b6fe35079b0522ff00b2b10e9fba19b.jpg?1623784620)
