Brake Lights stuck on

[Airb0rne]

Hi Everyone,


Hoping to find anyone with a similar experience and see what solution worked for you. Essentially the problem is that my MKV GTI has the brake lights on at all times when running, additionally, the cruise control won't work either. To clarify, the lights go off when the car is switched off, all other rear lights appear to work as normal.
One other note I'll add is that the problem temporarily resolved itself on two separate occasions (for seemingly no reason). The brake lights started to function correctly and cruise control started to work again for maybe 30mins or so, only to revert back to being stuck on and for cruise control to no longer work.


I've attempted the following already and so far nothing has worked:

1. Disconnect & reconnect battery.
2. Change brake bulbs - outcome was no different, lights still on.
3. Check all fuses - no fuses to change, all working but when I pulled the brake light fuses, the lights go out but come back on once the fuse is replaced.
4. Replaced the brake sensor under the master cylinder.
5. Replaced faulty third / high-level brake light - my high level light had been out for a while, I've seen some responses on other forums that this could be related but when replaced the new light is constantly on, same as the main two.

I'm assuming at this point its electrical, would anyone have an idea of where to look next?
Thanks

[Lucas_R]

Check the brake light switch located near the brake pedal. It registers that you are pressing the brake pedal and illuminates the rear brake lights.

I helped a friend with this exact issue a few months ago and it was a faulty brake light switch.

[MIG]

I think Lucas will be on the money here, that switch is the common one to fail.

The reason the cruise control won't work is the ECU cross-checks the two switches + brake line pressure, if anything does not match = no cruise. (it's a good safety feature really, think if the ECU does not register the disengage signal!)

This image may help with the location.