Brakelights stuck on sons 2014 ibiza 1.2 fr

Feb 23, 2023
10
1
Hi there new member
Stevie mcneill here I drive a blue 2018 Leon cupra 300.
My sons got a 2014 ibiza 1.2 fr with brakelights stuck on.
I've put a new brakelight switch onto master cylinder but still
On lights even stay on when I disconnected it, I've also checked
Al the fuses but none broke also got esp ,traction control lights
On dash also traction control not working.
Any ideas guys before it goes to a auto electrician
 

BigJase88

Jase
Apr 20, 2008
3,767
1,069
Is there not a brake light switch behind the actual brake pedal inside the car or is that the one you have changed
 

RUM4MO

Active Member
Jun 4, 2008
7,809
988
South Scotland
The brake (light) switch did move from the brake pedal to the master cylinder.

There have been a few people over the years with this issue, and I think that it ends up being a chaffed cabling issue, but from memory no one has actually come back and fully explained which cable and where.
 
Feb 23, 2023
10
1
Spoke to a mate whos a vw tech n he said defo no switch on brake peddle yet autodoc sent me after giving them reg number of the car a brake pedal switch but checked n a cant find it
 

RUM4MO

Active Member
Jun 4, 2008
7,809
988
South Scotland
I would have thought that there is still a switch on the pedal somewhere to give protection again a stuck/false WOT condition getting you into trouble, but that might also have been moved onto that hall effect switch on the brake master cylinder - which, or its wiring, is causing your problems. Interesting, one failure and you lose your WOT protection, nice one VW Group, so they could not get a pedal switch design to work reliably - so moved that function across to being on the brake master cylinder - but in doing so have ended up with chaffed wiring issues - probably!
 
Feb 23, 2023
10
1
Phoned seat garage today for advice told him the problem n said hed get back to me but never ,ive checked defo no switch on pedal so looks like auto elect
 

BigJase88

Jase
Apr 20, 2008
3,767
1,069
Are the correct bulbs installed in the rear lights.

Not sure what is ment to be there? Single filament / dual filament.

Same with type of bulbs. My cousin had a corsa and he put led bulbs in and they totally screwed with the canbus lighting and threw random bulbs on
 

RUM4MO

Active Member
Jun 4, 2008
7,809
988
South Scotland
What you need now, is for someone that has that version/age of Ibiza, to unplug the cable at the brake switch on the master cylinder - and report what effect that has, ie are the brake lights now on or are they off.
 

RUM4MO

Active Member
Jun 4, 2008
7,809
988
South Scotland
The cars with the old 1.4 16V petrol engine have lots of space to try that out, my wife's 2015 Polo 1.2TSI 110PS is a bit crowded in that area and that is why I'm not offering to try that out.
 
Feb 23, 2023
10
1
Gave car to a mechanic who reckons its master cylinder seemingly a magnet inside it that when you put foot on brake pedal it seemingly pushes a magnet that the brakelight switch under it connects and puts brakelights on .
This is last throw of the dice before it goes to seat because ive tried everything il let you know how it goes m8
 
Apr 26, 2023
7
1
ty m8.
I have try everything bulbs, connectors, bcm, switch and nothing changed.

Its a common problem but no one saying how they solved it.
I recently found this video
 

RUM4MO

Active Member
Jun 4, 2008
7,809
988
South Scotland
Yes @mono320 , that is currently the main problem, no one has yet reported back saying exactly how their car was repaired, maybe @Steviebhoy88 will come back with the answer!

Edit:- that is a very useful video though and demonstrates what should be happening when the system wiring is okay.

I seem to remember or partly remember some internet VAG motoring forum chatter about maybe something like the original brake primary cylinder push rod was not exactly the correct length and so it was touch and go if this switch worked okay, ie the magnet in the primary brake cylinder was not in the "best" position, I'm not sure if VAG provided a hall sensor(switch) that had its active area moved slightly to correct this, or under warranty if they just replaced the brake primary cylinder. I've just added these comments in case it helps someone now or in the future when they find this thread.
 
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Feb 23, 2023
10
1
After seeing the video i feel that it might be master cylender with magnet il let yous know when fixed im not doing job easy enuf to change but gettin air out systems not my thing
 

DTomas

Active Member
Jun 3, 2022
14
3
Hey, I had the same problem. I checked wires, 3 sensors, bulbs everything. At the end the problem was that I tried coding the central electric with VCDS and some value changed and made the brake lights stay constantly on. It was a headache for me
 
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