Park brake will not engage

[z4cAtS]

Hello.

After a bit of help, recently the park brake has refused to engage when applying the switch.
Holding the switch up causes the warning light to start flashing.
No fault codes appear to be logged.
I get a clunk noise when i do a EPB reset on my IID.

One thing is I have had a sunroof leak that has filled the passenger trough, this has been dried out, but may have affected things if the cable routes through there.

Any ideas?

Thanks, Paul

[z4cAtS]

Managed to get some time to take the switch out, I think it is a wiring / connection error as I can get it to work in certain orientations.

Any idea how it plumbs in under the center panel as I will probably see if I can get a spare bit of the loom / connector.

[Bodsy]

It’s part of the main loom, so would be a nightmare to change the loom.
Have you changed the switch? It’s usually that rather than wiring. Especially it if works if you change orientation. (But could equally be different strain /pressure on the wires at a different angle of course)

[PillowSmuggler]

When my last parking brake lever failed I had all sorts of errors, including the brake warning light flashing during driving when it wasn't even touched.

The lever has two separate independent switches inside, and both are checked to ensure the request for applying the brake or more importantly the emergency brake is plausible. When the same lever position is received from both switches at the same time, all is happy. If the car gets differing signals from the two switches it throws a fit, and this can happen if one switch has failed or partially failed.
Mine rattled when I took it out so something inside had let go and I think the road bumps were enough for the loose bit to make a contact every now and again.

As Bods says, the switch is the most likely culprit, but if not then those wires will need to be traced to discover where the problem lies. Let's hope it's the switch...

Behind the switch is a small flat blank panel with a curved comer. Gently entice this up (mine can be removed by hand with no tools) and you'll see a single torx holding the switch module in place. Remove this screw without dropping it into the bowels of the car, then slide the switch backwards into the gap; once back it'll be possible to lift the assembly out and remove the wiring harness. Re-fitting is the reverse etc etc.

By the way, if your auto gearbox interlink fails (the thing that won't let you move it unless the brake pedal is pressed) you remove that same little panel and stick your middle finger in and across at 45 degrees towards the gear lever just under the top cover. There's a small curved bit of plastic there that tries to remove your nail. If you lift this up about 5mm the gear stick will be released, which can be useful for servicing if you need Neutral instead of Park but the battery is out. If you can't find it (there's a g-spot joke here somewhere) then with the engine running and the gear in P, reach in whilst pressing and releasing the brake pedal and you will feel it moving and know where it is next time you need it.

[z4cAtS]

Cheers chaps, I think I will try to source a replacement switch.

[z4cAtS]

And for the grand sum of £16.50 delivered, I now have a working park brake.

May be doing a TYRO trial at the weekend so it really needed to work.

[PillowSmuggler]

Marvelous