Electronic parking brake fault / start-stop / auto hold

[Tullster]

Hi,

I have had my 2017 Cupra 300 for 6 months. It was recently in to have the 6th gear synchro replaced. Got the car back yesterday and since then have been having various issues - was wondering if anyone has any ideas on the cause - is it coincidence, or is it related to the gearbox work somehow?

I get a warning that there is a fault with the electronic parking brake. The auto function seems to work fine for a while - even with that warning - but will then stop working. The car at times feels like it is driving with resistance, although I've felt the wheels and they aren't hot as you might expect if anything was binding.

The Auto start-stop also doesn't seem to be working, and this evening at the same time as the auto brake failed after working fine, the auto hold also failed - I have warnings in the vehicle status for all 3 issues.

At the same time, the screen is fairly continuously showing the park assist, and the rear wiper keeps going even though set to the off position - almost like the car thinks it's in reverse?

I spoke to the garage that did the work and they've said I can bring it down for them to look for any codes, but that nothing they did should have an impact (I didn't actually mention anything other than the parking brake issue because the other stuff hadn't started happening).

Has anyone experienced anything similar? Any thoughts would be appreciated!

 

[McDorty]

Did you ever get this sorted. I’m having issues on a mk4 Leon and have narrowed it down to the natural sensor on the gearbox. I’m going to test it and check the wiring tomorrow.

I’m getting stop-start fault, auto hold and electronic park brake fault. It’s been with seat 6 weeks and they can’t fix it so it’s now down to me.

They keep telling me it’s the front radar that’s the issue, but it’s had that issue for the 3 years we’ve owned it. We bought it knowing it had received front end damage. These other faults are new and it failed it’s MOT because of the park brake fault.

 

[Tullster]

I did - it was the gearbox position sensor in my case. Luckily a 5 min fix - changed the sensor and it sorted all the issues. I'd be surprised if Seat didn't think about this though...

 

[McDorty]

I did - it was the gearbox position sensor in my case. Luckily a 5 min fix - changed the sensor and it sorted all the issues. I'd be surprised if Seat didn't think about this though...

I’m going to look at mine tomorrow as I suspect it’s the exact same issue you had.
When viewing live data the values don’t change at all when you move the gearstick.

All seat we’re interested in was charging me £1100 for a front radar module. I had to insist they concentrated on the brakes as that’s why it failed its MOT. Eventually after 5 weeks they found a damaged and sensor which I changed yesterday in the hope it would cure the park brake issue.

Out of interest. Where did you buy your sensor?

 

[McDorty]

For anyone who has the same issue. After some investigation I found one of the cables snapped at the plug on the gearbox neutral sensor. I ordered some plugs and extended all the wires a little as they were very taught. Cleared the codes and car is back to normal.