Granddaughters car in Florida ,l live in NY. Car has 43,000 miles, she has owned it several years. When car is off, you can step on the brakes and the brake lights work, release the pedal and they go out. Manually pushing the plunger on the brake light switch does the same thing.
When the key is on or the car is running the brake lights are on and will not turn off. No other lights are on unless you turn them on. All of the brake lights come on , right, left and center. Pushing the plunger on the brake light switch will not affect the brake lights as long as the ignition is on.
Per internet suggestions the battery was disconnected and reconnected. That did nothing.
It was not the switch, my son changed it for her today even though I told him it was not the switch. I also told him it was probably the TIPM but did not want him to change that without a diagnosis.
The car is at his mechanics now.
tester, thanks for the class action information.
Keep the old switch, it may come in handy later. Along the lines of alternative theories to the expensive one mentioned above, I’m trying to think if a short circuit somewhere could cause that? Probably all the brake lights on the power side are connected together and sourced by one wire. I suppose if another wire in the harness was shorting to the brake light wire, that could be an explanation. Assuming that other wire was powered up only with the key on or the engine running and otherwise an open circuit. It’s also possible the brake lights could be powered from their ground lead in some weird way. So make sure the ground connection to all the brake light bulbs has a low ohm connection to the chassis. That’s easy enough to verify. That ground connection is a wire bolted to inside the trunk between the two rear light assemblies on my Corolla. It would be possible to break that connection if something heavy in the trunk were to slide around and nick it.
fyi, I took a looking at the wiring diagrams; it appears the brake light switch is an input to the “totally integrated power module” and the wire that powers the brake lights is an output of that module, originating at pin 13 of connector c3, an orange wire, which turns into a white wire with orange stripe at connector c104 and remains that color all the way to the brake light bulb socket.
There’s only one TSB related to the power module I see, a customer interest bulletin 8-7-8A, concerning the anti-theft system preventing the engine from cranking. Totally integrated power module sounds kind of scary, Totally integrated seems good, but if it doesn’t work, the owner seems to be totally screwed I guess it is like other consumer electronics these days, nicely priced and provides a lot of functionality when it works, but when it fails there’s no repairs feasible, it is back to the store for a new one. I keep a brand new DVD player on hand at all times for this reason, b/c my experience says my current one is going fail with 5 years of being put to use. Replacing that module appears to be a pretty big job b/c much of the engine wiring harness has to be replaced in the process. And components from the old module have to be transferred to the new one.
I am seeing prices of $400 to $500 for rebuilt ones. I wonder what would happen If you just cut the wire from the brake light to the TIPM and cut the brake light feed wire in the back and ran a wire from the switch to the lights. I think this car has seperate amber turn signals but not sure.
That’s what the service data implies also. I think what it said was once they are adjusted for the particular brake pedal geometry, they can’t be re-adjusted. But it might be possible to re-use one in the same spot that it’s already been adjusted for. Don’t know.
The schematic implied the brake light filament isn’t shared w/anything else. So that’s theoretically possible. The brake light switch on that car is more complicated than most brake light switches I’ve seen. So that might complicate things. Also the switch contacts might not be capable of handling the current levels the bulb’s require.
Another problem with cutting the brake light swtich input to the module however is that it might foul something else up. You might not be able to start the car for example, or not shift out of P, due to the brake/transmission safety interlock.
If I had that problem I’d temporarily disconnect the brake light output from the module and monitor the output voltage with a volt meter without anything connected to it. If the module’s output voltage is correct then, the problem isn’t the module, but something with the wiring after the module. I have to say however, that it is looking like a bad module.
One other idea, the signals aren’t getting from the brake light switch to the module input correctly. Suggest to double check that before replacing the module. I think there are three signals that come from that switch.
It was the TIPM , the mechanic fount full voltage output from the TIPM to the brake lights whenever the key was on, reset the TIPM and the brake lights are working normally now.
If it happens again they will try a used TIPM.
Excellent work by you and your mechanic OT. Glad you got those stubborn brake lights working again. You’d think that just disconnecting the power from the module would result in a hard reset, but I guess it’s not than simple.
I guess it is like other consumer electronics these days, nicely priced and provides a lot of functionality when it works, but when it fails there’s no repairs feasible, it is back to the store for a new one. I keep a brand new DVD player on hand at all times for this reason, b/c my experience says my current one is going fail with 5 years of being put to use. Replacing that module appears to be a pretty big job b/c much of the engine wiring harness has to be replaced in the process. And components from the old module have to be transferred to the new one.