gearbox malfunction a6 c7 allroad 2012

[chris.d]

hi all,i am in need of some help here.
just went to start the car and get message gearbox malfunction, tried to start the car ,turns over and sometimes stars for a couple seconds and dies ,and getting messages on dash for lots of faults now h,brake lights and so on ,checked under scuttle panel for water (as i think that is where ecu is on the drivers side )but none .., last time i drove the car all was fine but it was chucking down rain heavy though !! .
any ideas ??????????????

[kite]

Sounds like a low battery to me.
Engine starting and cutting out could be the immobiliser.

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[chris.d]

Sounds like a low battery to me.
Engine starting and cutting out could be the immobiliser.

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hi thanks for your thoughts , but it is turning over quite strong and i did not have any low battery warning recently

[beemerboy9]

It's likely a poor connection, but you will need to get the car scanned to find out the location.

15 years ago I remember a gearbox going into limp mode because a cable on the brake pedal had become disconnected. The problem was only diagnosed after 2 gearbox rebuilds!

[chris.d]

It's likely a poor connection, but you will need to get the car scanned to find out the location.

15 years ago I remember a gearbox going into limp mode because a cable on the brake pedal had become disconnected. The problem was only diagnosed after 2 gearbox rebuilds!

hi thanks for that hope you are right .i have rac coming in the morning so i get diagnostic free .:D

[marciolo]

I would check gearbox cable connection

[chris.d]

ok. rac man been here for an hour did a reset of all the faults .then his diagnostics states no communication between gearbox brakes.steering etc
so looks like i have to get it to a garage but local one is shut until jan 4th so will have to wait until they re open .as they do have a audi trained mechanic who does the audi repairs at a reasonable rate

[philipharmes]

Have you checked all the fuses in the engine bay, at the ends of the dash & in the boot ?

One large fuse may provide power for several electronic modules.

[chris.d]

Have you checked all the fuses in the engine bay, at the ends of the dash & in the boot ?

One large fuse may provide power for several electronic modules.

hi yes rac man went through the fuses

[Elansear]

Hi as has been mentioned by others it sounds like a wire loom problem, perhaps as you mentioned heavy rain, water ingress in a connector possibly under the car. As you are going to have to wait might be worth getting a big can of WD40 and give any accessible connections a good spray, you have nothing to loose perhaps worth trying to get a cheap hand scanner to assist in seeing if that helps. Good luck.

[chris.d]

Hi as has been mentioned by others it sounds like a wire loom problem, perhaps as you mentioned heavy rain, water ingress in a connector possibly under the car. As you are going to have to wait might be worth getting a big can of WD40 and give any accessible connections a good spray, you have nothing to loose perhaps worth trying to get a cheap hand scanner to assist in seeing if that helps. Good luck.

hi cheers i might give that a try ...if it ever stops raining here

[lynalldiscovery]

Check all the pine are still in the back of the OBD socket, seen a few with the odd pin pushed out thus losing comms with some ecus.
I have seen it on several trucks, not had much to do with car repairs beyond my own, plues as its my won I am careful with the test kit.

[chris.d]

still no luck i have had a vag trained mechanic plugged it in to his diagnostics it and it seems to be definitely a wiring issue,i have never seen so much wiring on a car .he has unplugged loads of connections but as yet we can not locate fault . he is coming back to have another go later this week .there is no communication between electonics :banghead::banghead:

[beemerboy9]

as they do have a audi trained mechanic who does the Audi repairs at a reasonable rate

Ideally one wants a really expensive mechanic who has been there, done that and got dozens of T-shirts!

[arman123]

check passenger floor carpet is it wet?

[chris.d]

check passenger floor carpet is it wet?

hi
no all floor footwells are dry ,no sign of water any where in the car.

[chris.d]

hi all
just to update on this .i tried everything i could .but eventually gave up and recovered car to audi dealership
after 5 hours of testing ...
it turned out to bej33 gateway control unit
just drove car home, good to have it back,i missed it :D:D

[WesleyP]

You were lucky there! I had a similiar problem, car recovered to an Audi dealer, turned out it was a mechatronic unit failure in the S=Tronic box. A coolant valve (N82) that opens and closes to allow a flow of coolant around the gearbox as required, was leaking. Fluid runs up a cable through the connection into the Mechatronic unit. I think there had been some problems for a few weeks as I occasionally had the feeling that reverse gear was either not engaging properly or not very sensitive in operation. Maybe its the shock of a plus £4k repair bill. but it does seem smoother in operation now.