09 cc handbrake issue

[mactac1701]

have had the cc for a year now on an 09 plate, just coming up to the second service, have noticed for a while when you start the car (http://www.vwaudiforum.co.uk/forum/#) the handbrake occasionally comes off on its own. I have also had the handbrake warning light and message on the display, come on for a couple ofminutes and then go off. I have also had the car while locked and me being nowhere near it roll off across the car park, when the handbrake was on, i know it was on because i was sitting in the car, i then stood behind the car (in the direction it rolled) and also went to the back door of the car while it was stationary.
According to VW, the car has not registered any of these as faults, and so will not repair (http://www.vwaudiforum.co.uk/forum/#) the damage caused when the car rolled into the wall. anybody else with any similar problems.

[johnloaderuk]

If you do a search on the Passat B6 section you'll find you're not the first one any of these faults has happened to. Others have mentioned cars rolling off on their own, although it's rare, and electronic handbrake issues - unfortunately not quite so rare. Follow: http://www.vwaudiforum.co.uk/forum/showthread.php?t=85460&highlight=rolled where you will also find another link to follow as well.

[martin1810]

You can hear the rear park brake motors come on. Once they are on., they can't accidently come off. It's a fail safe. So if you listen to the motors, the car can't roll away. So never leave the car until you hear the motors wind.

[mactac1701]

i was hoping I was not the only one, however this still leaves a battle with VW to get the issue resolved and the car made safe.
Whereas the damage to the car is luckily quite superficial, a few scratches to the back bumber and a now not working parking sensor system it would be good that these get repaired and the car made safe.

[mactac1701]

the parking brake had activated, including the whirring noise as the brakes come on, the car was stationary on a slight slope. I have since tried all i can think of to try and leave the handbrake off, to see if it could be done accidentally, but cant see a way at the moment. when you leave the car with any type of brakes off where it was parked, it immediately rolls off.

[martin1810]

The caliper motors are geared. The only way I can think of your fault occurring is if the teeth on the gearing are damaged. That only usually happens if someone has fiddled with the rear calipers. No womder the dealer is confused.

[mactac1701]

The dealer does not give the impression that they are confused in any way, they just say that the computer does not register any sort of fault so no further investigation will be done. However the other bit that confuses me is that the one off fault with handbrake light and message on the dashboard didn't register as a fault either. Surely this would have registerd on the computer even if it was a one off?

[martin1810]

"The EPB control module takes information from an inclination sensor, clutch position sender and accelerator position sender. The EPB remains engaged until the control module calculates that engine torque is great enough to overcome “roll-back”. At this point the EPB is released." That is for auto release. The fact that your brakes came off by themselves suggests the control module is faulty.

[mactac1701]

Well, vw are still sticking to the computer says nothing is wrong with the car, so thats it, it would appear that I am in the wrong. The handbrake still dis-engages occasionally when I start the car, still occasionally has the dashboard warning of a faulty handbrake, still occasionally does not dis-engage when pulling away, still occasionally comes on when pulling away, and still occasionally takes 2 to 6 attempts at pushing the button before it will come on. However as the computer says nothing is wrong it must be opperator error. Damn i must be a bad driver. oh well 2nd service is coming up, will have to go through the motions again and get them to see if the computer has changed its mind.

[gamichea]

I'd be looking for another dealer/workshop. One where brains are applied to problems as well as computers.