High level brake light flashing like a strobe...

[nugget]

Hi all

When first turning the lights on in my 2003 LC the brake lights come on and stay on for about 5-10 seconds, and the high level brake light flashes randomly like a strobe light. This happens when first starting up the car or while driving. If I do it while driving I have noticable power loss (I'm assuming this is because the ECU is thinking Im trying to left foot brake and cuts the power).
I've searched and not found anyone else who's had the same issue, but suspect from other brake light related threads it could be the brake switch under the dash? (I've already had this repalced once udner warranty when the car was a year old as the lights weren't coming on until I virtually had the brake pedal to the floor) I don't have Vag-Com so can't check for fault codes? Any ideas/suggestions?

Thanks

Jon

 

[nugget]

Got worse this week, my brake lights are now permanently on whenever the lights are.
I've changed the brake switch (from purple to green) with no improvement. Managed to get some VAG COM output and have the following error. Having googled the error all solutions point to replacing the switch which I've now done.

Can anyone help?

Jon

VAG-COM Version: Release 409.1-US


Chassis Type: 1M - Seat Leon
Scan: 01,02,03,08,15,17,19,22,35,46,56

-------------------------------------------------------------------------------
Address 01: Engine
Controller: 06A 906 032 MJ
Component: 1.8L R4/5VT 0003
Coding: 11510
Shop #: WSC 78898
VSSZZZ1MZ4R027404 SEZ7Z0C2183072
1 Fault Found:
16955 - Brake Switch (F): Implausible Signal
P0571 - 35-10 - - - Intermittent
Readiness: 0000 0000

 

[Binksy]

I would say its the switch again surly! are you sure its the right part is it OEM? is it fitted properly? I would go get another switch after making sure that one is deffo in correctly it might well be a dud switch that's the only think I can think off m8. maybe someone else has a better solution ;/

 

[nugget]

Cheers, it's a weird one !
The brake lights work fine, until the main lights are turned on, then everythings on. Although the only difference since installing the new switch (got from GSF using the part number off here) is now the brake lights do at least get brighter when I push the brake pedal....

Think Im going to give up and take it to a garage.....

 

[Binksy]

Ah well in that case it might be a lose or faulty earth on you headlights or else where. I'm really not sure! wouldn't think its the switch then, maybe the garage might be best.

 

[Slimy]

I'd agree with Binksy, that sounds like the old Ford Escort problem of dodgy earths. Your 'implausible signal' means that instead of the 12 volts going through the lights and down to earth, it's coming back through the brake light.

you've got four sets of lights (one on each corner) so you need to determine which one is not connected properly. Unplug all the bulbs in one cluster, then switch your main lights on. If your brake lights don't come on, then it's that cluster that's not got a decent enough earth.