3.0tdi quattro wont start

[bluecamp30908]

Hi,parked the car this morning A6 C6 3.0tdi quatttro,and when returning put the key in ignition turned it and Nothing,alarm works,central locking,interior lights and radio,but no dash lights absolutely dead.
Called out RAC guy checked battery(fully charged),fuses all appear ok and tried jump leads,spare key still nothing,getting it recovered in ,morning to independant Audi dealer,but any ideas in the meantime.

[nealeb]

My A6/C6 3.0TDI Quattro used to have the odd moment when it seemed to be dead. It happened maybe every 3 months or so, and there didn't seem to be any particular set of circumstances in common except that it was usually from a cold start. You turned it on, tried to start, and nothing happened. I found that turning it off, leaving it for a short while (10sec?) and trying again always worked although it maybe needed a second retry occasionally. Never did find out what the problem was as it always cleared itself. Maybe an issue with the immobiliser not recognising the key first time round?

[kite]

is it auto ?
could be the inhibitor swith on the gear selector
Does it need the brakes on to start, could be a failed brake light switch.

[bluecamp30908]

Hi,thanks for the reply,it is auto and I can't remember if the brakes are required or not. I have read an american article where it seems a guy had the same issue and it may be a module linked to the ignition switch a guy over there had it replaced and the keys re-coded and he says that cured it. It should be with my local specialist by 9.30 in morning so fingers crossed,just trying to find the button thats supposed to be under the ashtray in order to move the gear selector from park to neutral,don't seem to be there.

Cheers

Ian

[kite]

try turning the key pressing the brake and wiggle the gear selector all at the same time

[bluecamp30908]

Hi,just an update re the starting issue,it turns out to be the Start,Access and Authorisation Module which turns out is an integral part of the steering colum which means the steering colum has to be replaced and is in the dealers now(who have been by the way fantastic) and should be back on the road early next week.
Had an aftermarket warranty (RAC Gold Plan) and of course the unit is not covered,I really wonder if any of these warranties are worth the paper they are written on,but it won't be left at their refusal,more to follow.
Thanks for the assistance.

[mark.lownsbro]

Hi
I had the same problem with my Audi Q7 3.0tdi
when I put a volt meter on one of glow plug leads turned on the ignition nothing..
i disconnected the the coolant temp sensor and bingo
the glow plug leads reading 1.72volts,
changed the coolant sensor and now car starts first time every time.
coolant sensor is located at rear of right side of engine under the pipe for mass air flow pipe,
you have to remove the black plastic housing bolted to turbo with 2 size 30 star drive set screws
the sensor in located below, there a clip that holds the sensor in.
you can't see the sensor until all pipe work as been removed..

[MarkTM]

Remember to ask them for the old unit back, and also (since I'm assuming you're paying for it?) a printed scan of the car.

No idea where you or your fantastic dealer is located since you don't have a location listed...probably a good idea for the future as that way local forum users with VCDS could have run a free scan for you :D

[mark.lownsbro]

Fitted the part my self as I am an HGV fitter and also I have a diagnostic lap top
No faults codes showing
Comment is to advise other's with the same problem
away start by checking the cheapest first
Tony

[markaz]

For future reference if it was an immobiliser problem it would still turn over but not fire IIRC

[gupsterg]

Hi,just an update re the starting issue,it turns out to be the Start,Access and Authorisation Module which turns out is an integral part of the steering colum which means the steering colum has to be replaced and is in the dealers now(who have been by the way fantastic) and should be back on the road early next week.
Had an aftermarket warranty (RAC Gold Plan) and of course the unit is not covered,I really wonder if any of these warranties are worth the paper they are written on,but it won't be left at their refusal,more to follow.
Thanks for the assistance.


Remember to ask them for the old unit back, and also (since I'm assuming you're paying for it?) a printed scan of the car.

No idea where you or your fantastic dealer is located since you don't have a location listed...probably a good idea for the future as that way local forum users with VCDS could have run a free scan for you :D

Hi Mark,

OPs post is dated 12-01-2012,06:11 PM , last activity on account 10-02-2013 09:34 PM , Bluecamp30908 profile page.

(http://www.vwaudiforum.co.uk/forum/member.php/99306-bluecamp30908)mark.lownsbro (http://www.vwaudiforum.co.uk/forum/member.php/228441-mark-lownsbro) bumped an old thread by his post.

[MarkTM]

Ooops!:Blush2:

[noscream]

Hi,just an update re the starting issue,it turns out to be the Start,Access and Authorisation Module which turns out is an integral part of the steering colum which means the steering colum has to be replaced and is in the dealers now(who have been by the way fantastic) and should be back on the road early next week.
Had an aftermarket warranty (RAC Gold Plan) and of course the unit is not covered,I really wonder if any of these warranties are worth the paper they are written on,but it won't be left at their refusal,more to follow.
Thanks for the assistance.


Talking about paper warranties are written on, the best one I ever used outside a dealer was "Warranty wise" it was not cheap (about £1000/year on 70k 5 year old) but never argued, currently using "Warranty direct" around £400/ year on a 4yr old 70k (both A6 3.0Tdi) and no end of problems with them trying to cut down the labour & parts covered.

Glad your getting it sorted, nice car A6 C6 3.0TDi Quattro , I had a 2007 one..

[Kendo228]

Hi Mark,
my07 q7 has started playing up. It randomly fails to start but shows no error codes etc, I've just replaced the battery and now it's still doing it. Drive it 15 miles park it up then 1hr later it fails to start, does this sound similar to your issue?

regards

kenny

[mark.lownsbro]

Yes that is the same problem as I had, fault continue until I fitted new starter motor, engine wouldn't spin over quick enough to fire,
Once the engine reaches a certain temperature the glow plug won't work, I had the same problem in warm weather, had this problem for 18month, everyone garage advised me not change the starter but I decided to go with own instincts as a qualified HGV fitter
Bingo problem solved
Since fitting a new genuine Bosch starter motor 8months ago the car has never failed to start,
Turn the key it fire up all weathers in 3/4seconds max
Unless you have the equipment it's isn't a easy job,
I had to drop the front sub frame to get starter motor out, 4.5hour job.

[itavaltalainen]

Which battery did you put in and what did you use to read fault codes (and which ECU did you read)? Have you checked live measuring blocks for main terminals and voltages with ignition on, engine running etc?

When you are trying to start what does it do exactly? Does the starter motor turn, do the lights go off etc?

[mark.lownsbro]

I plug in my Dyagnostic lap-top
Didn't have any fault codes,
I fitted a new Bosch battery, I had the battery programmed into to car, lasted about 6 weeks then the problem came back,
The local auto electric service's couldn't find any faults also,
Not sure how or what they tested,
They told me next it happens ring them,
Hence I went against his advice and bought a starter motor problem solved in my case

[itavaltalainen]

I was actually asking Kendo :D

What hard/software are you running on your 'diagnostic laptop'? You can read out starter rpm with the right diagnostics h/w & s/w.

[Kendo228]

Mark,

ive taken it to an auto electrical mechanic who checked to see if the battery was draining, for over 2hrs. There was .03 for a drain which they said was more than exceptable, however they stated it had the wrong battery on it (it was replaced 2 weeks earlier by a mechanic). A new varta was fitted and has been good until tonight!! The wife come home from work, parked up for an hour then went to go shopping and it wouldn't start!! No warning lights come on, and the battery seems fine however it wouldn't start. An hour later she went back to it with the spare key and it fired up straight away �� Confused

[itavaltalainen]

Have the starter speed checked, that is what I tried to hint in my posts above..... you should get around 200-250rpm.
.03 drain, what unit is that meant to be? 0.03V, 0.03A? Was the battery in the car while this was measured? It can take a long time for the car to go completely to sleep so a current measurement can be higher before the CAN bus goes to sleep.

If the starter speed is too low it won't start. Easiest way is to use VCDS (look for someone on the VCDS user map - I live in Malvern for example) and log it and check it with VAG scope afterwards.
It is quite common that older starter motors get slow and don't manage to get quite enough power to spin up engine sufficiently - on a petrol this won't matter too much because you have a spark plug igniting fuel. On a compression reliant engine you need quite a lot more revs to get sufficient temperature increase for auto ignition.

Fault codes are like toddlers, they might be able to tell you where it hurts but since they can't talk properly I would not solely rely on them or trust everything is OK in their absence.

[dan2485]

Mark,

ive taken it to an auto electrical mechanic who checked to see if the battery was draining, for over 2hrs. There was .03 for a drain which they said was more than exceptable, however they stated it had the wrong battery on it (it was replaced 2 weeks earlier by a mechanic). A new varta was fitted and has been good until tonight!! The wife come home from work, parked up for an hour then went to go shopping and it wouldn't start!! No warning lights come on, and the battery seems fine however it wouldn't start. An hour later she went back to it with the spare key and it fired up straight away �� Confused


Try looking at the J329 relay as if playing this will explain what happened above.

Problem with key or starter? - Page 3 (http://www.vwaudiforum.co.uk/forum/showthread.php/159080-Problem-with-key-or-starter/page3)

[kambeu.banda]

What if every morning you try to start the car it gives u the same problem and after forcing it to start it gives u a white grey smoke from the exhaust

Sent from my HUAWEI VNS-L21 using Tapatalk

[swalker]

Forcing? I'd go injectors

[Cartsone]

Hi, how did you find out about that please?
My Audi Q7 broke down and we tried this and it started
I just wanted to thank you and find out what causes this problem?