Cruise Control Fails at the same time as hold/assist

[Dolybont]

I recently bought a 58 Reg 09 model A4 Avant, and at that time the handbrake switch worked perfectly as did the cruise control.

I first noticed that the hold didn't release on the parking brake when I attempted to drive away. OK no problem, I can easily release the brake manually.

Shortly after I discovered the cruise control wouldn't engage. That is a pain - I use it regularly.

Can anyone give me a clue what it might be. I would rather not pay £85 for a diagnostic check if it can be avoided.

[markp306]

I recently bought a 58 Reg 09 model A4 Avant, and at that time the handbrake switch worked perfectly as did the cruise control.

I first noticed that the hold didn't release on the parking brake when I attempted to drive away. OK no problem, I can easily release the brake manually.

Shortly after I discovered the cruise control wouldn't engage. That is a pain - I use it regularly.

Can anyone give me a clue what it might be. I would rather not pay £85 for a diagnostic check if it can be avoided.

I assume you have your seat belt on when the brake won't auto-release for you, so can you also check if the reversing sensors mute when you apply the handbrake? If not, there is a chance that might be the same problem I had on my avant, namely an ECU failure.

No idea about the cruise, sorry.

[Dolybont]

Thanks for your interest. Yes, seat belt engaged. No the sensors don't mute. I have been reading a thread where the 07 model displayed the same symptoms when a £15 switch on the clutch lever failed. The 09 model appears to have incorporated that switch into the £140 master cylinder. Progress? Any master techs out there?

[a8 tech]

If this happens all the time then you need firstly a scan of all control units then you need to check the on/off status of the brake switch and clutch switch

If the clutch switch fails it defaults to the engaged signal which will disengage the cruise and hill hold

8k platform clutch switch is mounted to the clutch master cylinder and its a little pig to change

will the engine start without depressing the clutch

[M1tchy]

I'd say you need a VCDS scan mate


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[Dolybont]

Thanks for reply. Really interesting. No, Engine wont start unless the clutch is depressed. M1tchy, is that the diagnostic check they want £85 for?

I know a bloke with a Merc diagnostic machine. Wonder if that would work.

[M1tchy]

Yeah its a diagnostic scan, have a search on here for VCDS location map and see who lives locally to you and if they will do you a scan. A lot of members on here have the proper Audi software and will do a scan for you in exchange for beer tokens. If you are in west wales I'm willing to help you.


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[Dolybont]

Great idea! I have located the map and found 2 members just down the road in Telford. Trouble is I cant send them a message until I've got 10 posts in so looks like I'll have to rabbit on for a bit. Unless PNS2007 and Kieron Mullan are looking in of course. :) Really appreciate you Guys looking out for a newbie!

[M1tchy]

No worries! Unless someone can beat me to it, I will send a message for you on Sunday when I get back to my computer (don't think it can be done on the app)


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[Guest 2]

Messages sent :)

[M1tchy]

I knew it would be you that got there first lol ;-)


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[a8 tech]

best taking your vehicle to a certified diagnostic technician with knowledge of the vehicle systems rather than a weekend fiddler with vcds and google :)

[Dolybont]

I hear what you say and may end up doing that, but..........

[ru55]

This morning I found my 58 plate Avant has a very similar problem. As well as the handbrake not disengaging and cruise not being activated it also had a TPMS failure warning at the same time. Did you manage to find out what the problem was?

[Dolybont]

I didn't get any form of warning and I am not totally certain of the cause. I am pretty sure though, from research and professional help, that the cause is the clutch switch as detailed in earlier posts. I am waiting for a proper diagnostic check in the coming week and I will share the result when I have it. I suspect it will cost me £150/200 to have it fixed. Do I value the cruise that much? Certainly not the hill hold.

[ru55]

I will be calling my local Dealership tomorrow to discuss. I have the MOT protection package but suspect it will not be covered - as always. But having the two of the same three issues arise ( and I suspect you do not have TPMS) at the same time indicates the same source issue.

I will report progress.

[AP_Automotive]

We would be happy to take a look for you, we are based in Telford.

www.apautomotive.com

[ru55]

We would be happy to take a look for you, we are based in Telford.

www.apautomotive.com (http://www.apautomotive.com)

Thanks but I am just south of Glasgow so less than local!

[Guest 2]

Thanks but I am just south of Glasgow so less than local!

I think it was aimed at the OP of the thread.

[ru55]

I think it was aimed at the OP of the thread.

Oops - of course - bad geography!

[ru55]

An update - sent car to main dealers and came back with a parking brake control module failure. Replaced at a cost of £420 - not sure if this is reasonable value but better to have a fully functioning car. When I asked if this was covered by the MOT protection I was advised that because the car was not having an MOT then no. Perhaps a school boy error as I should have waited for the MOT that is due in 3 months and see if it was covered. I have asked Audi UK for clarification of the cover and whether they are prompting unsafe driver behaviour by waiting to fix problems

Hope this his may be helpful to others who end up with the same symptoms.

[markp306]

An update - sent car to main dealers and came back with a parking brake control module failure. Replaced at a cost of £420

It was the same issue as on my previous avant then. I didn't realise it cost that much!!
'Lucky' for me it failed early on, so was a warranty fix.