Auto Hold EPB Error

[gazza57]

Recently purchased a 1.6 105PS Blue motion Tdi SE Tech from our local dealer, four days after I picked it up, an error message appeared on the central display:

Error Brake Hold Unit Fault

The Auto hold light (usually on) went out, and I pulled over, parked switched off and restarted, Auto Hold light returned and everything appeared normal.
Returned the car and they scanned it for fault codes, later told me that the codes advised a faulty switch inside the cabin and replaced it under warranty.
Four weeks later, same again car showed Error! Auto hold brake unit Fault and Auto hold light went out.

Now we know that the probability of it being another faulty switch is infinitessimally small, so it would appear the fault was either wrongly diagnosed or the switch was never replaced at all, Im not sure which.
Im told the early passats which had this EPB had a similar fault, but that has since been rectified, this is the second visit to the dealer in as many months, Im not very confident that this will get sorted, I had an initial 30 day no quibble option to return the car, but that has obviously passed, but the original fault which was reported just four days after delivery still has not been successfully cured, so if they are unable to resolve this, then I feel I should get the option to replace the car as the original fault has still not been resolved, it is surely not acceptable to offer a 30 day no quibble guarantee and to merely see that 30 days out without resolving any faults to obviate yourself of any liability to replace the car?

Gazza57

[microwork]

I had the same problem. I left the car with the dealer and after 2 weeks the problem was sorted.... they thought it was the park break motor - put new one in and problem was still happening. Turned out to be the ABS pump - I have had no bother since. Thank god.

[itavaltalainen]

Had that once too.... it was the handle of my coffee mug pushing down on the auto hold button for about 15 minutes

Joking aside, which switch did they replace? AH or EPB?
Could also be a wiring issue. Speak with dealer, next step would probably be to check wiring and replace whichever switch hasn't been replaced if wiring loom is ok.

[gazza57]

The AH switch was replaced, the fault code this time indicated a failure of signal from the switch, as the switch is new that can't be the problem, it could be the cable but I asked them if they checked the continuity and insulation resistance and they said yes, it was good.
That leads me to think that perhaps a signal from somewhere which should get sent to the AutoHold switch is not being sent and the AH times out to error, however I'm also told the ABS pump sends a signal to the AH unit to apply the brakes when the wheels are detected as stationary from the ABS sensors on each wheel, so perhaps the ABS pump interface or comms from the ABS unit is to blame, it's merely a matter of elimination.

A bit brassed off with having to leave it for an entire day each time though

Gazza57

[Ian91]

Auto hold problem with my six month old Golf, have given up as VW say it's a characteristic of the car, no error message but the auto hold does not release cleanly causing the car to jerk when setting off. I have read that you can adjust the auto hold settings thro VCDS ( ABS adjustment thro hill hold assist menu, settings are Normal, Early, Late) but a bit reluctant to change the setting, plus haven't got VCDS and safety/warranty issues. Looks like VW struggle to fix these problems with the system they have fitted and diagnostics don't pick up these faults.

[gazza57]

Ian91

My wife's golf parking brake very occasionally doesn't release quite as promptly as I'd like, but using it does take practice, I've had an EPB in my Audi and struggled with it initially, but what I do is when the brake is on, just lift the clutch until it begins to bite and gently dab the throttle. This works for the golf too.
In your case as it's a DSG box, gently dabbing the throttle should release the brake, it works off of the ABS pump which gets pulses from each of the wheels ABS sensors, so it sends a release signal to the EPB once the ABS sensors tell the pump the wheels are beginning to move, by the same token it knows when to apply the brake when the wheels are no longer tuning and generating a pulse train to the ABS pump.

If you haven't got a fault code or had an error message displayed chances are it is just down to technique, I've never had the problem in the golf but my wife has, now she used the same technique and hasn't had a problem.

Gazza57

[Ian91]

Ian91

My wife's golf parking brake very occasionally doesn't release quite as promptly as I'd like, but using it does take practice, I've had an EPB in my Audi and struggled with it initially, but what I do is when the brake is on, just lift the clutch until it begins to bite and gently dab the throttle. This works for the golf too.
In your case as it's a DSG box, gently dabbing the throttle should release the brake, it works off of the ABS pump which gets pulses from each of the wheels ABS sensors, so it sends a release signal to the EPB once the ABS sensors tell the pump the wheels are beginning to move, by the same token it knows when to apply the brake when the wheels are no longer tuning and generating a pulse train to the ABS pump.

If you haven't got a fault code or had an error message displayed chances are it is just down to technique, I've never had the problem in the golf but my wife has, now she used the same technique and hasn't had a problem.

Gazza57

Tried various scenarios but the fault seems to be worse on the 1.4 DSG GT with the new 150PS engine. The technician drove my car and exactly the same model (petrol with 150PS engine) and they both did exactly the same ie jerked when pulling away on the flat. I loaned a Golf SE and SUV Golf and they operated fine, ie smooth release when using auto hold.
Because my model and a comparison with the same car had the same result both VW UK and the dealership say it is a characteristic of the car and there is no fault. It appears to be a common fault on the 2015 petrol 150PS DSG Golf reading posts on forums.