Engine cuts out

[Vanessa]

Hi had the car from new and when driving it will stop when braking at a junction or round about 

it is not stalling, you cannot make it happen and it will be fine for a number of weeks (miles)

audi have had it and say there is no fault with it, but there is, all the other cars I've had whilst they've looked at it haven't done this

has anyone else had this or heard of it as I am worried that I will be left with an expensive rogue car !

[Envy]

17 hours ago, Vanessa said:

Hi had the car from new and when driving it will stop when braking at a junction or round about 

it is not stalling, you cannot make it happen and it will be fine for a number of weeks (miles)

audi have had it and say there is no fault with it, but there is, all the other cars I've had whilst they've looked at it haven't done this

has anyone else had this or heard of it as I am worried that I will be left with an expensive rogue car !

Hi Vanessa: 

You have Start / Stop technology on your A6? Are you sure it is not his causing the engine to "cut out"? Would need more detail of circumstances to be certain. What do you do when you have stopped and the engine is stopped - attempt a restart with the start / stop button? Does this take 2 presses?

 

[Trevor]

Hi Vanessa....welcome to the Forum

I'd agree with Envy it sounds like the stop/start operating but I believe you can switch this function off

Cheers  Trevor

[Vanessa]

Hi

Yes it has the Start/Stop technology, and I have to press the start again, sometimes twice, generally I'm too focused on making sure no one is going to hit me to be taking too much notice of this though!

Also Trevor, I didn't know I could switch it off, how do I?

Thanks for the replies

Vanessa

[Envy]

Hi Vanessa: I don't want to come across as patronising but have you read the manual? The on off button for the Start / Stop is in the row of buttons above the Climate controls, Mine is to the left of the Parking Assist Button.

My A6 is a '16 Automatic model and the start stop does not function every time. If you stop at a junction and it is in a condition to stop the engine then you get a green icon on the dash between the dials  and the rev counter drops to "ready" (not 0). If stop start is not functioning then the icon between the dash dials will have a strikethrough and be white. 

When the engine stops look at the rev counter - does it drop to ready? You mentioning pressing the Start button twice would suggest that the car has stopped the engine purposefully and on your first press of the start stop button you have actually "turned of the ignition" with the second press restarting the engine. 

Is your car auto or manual? With a manual A5 Cab I had on loan it would only stop start when out of gear with clutch released. See link below...

https://www.audi.co.uk/glossary/s/start-stop-system.html 

 

[Magnet]

Hello Tom and Vanessa,

It does bring a smile to my face on a rainy morning! 

It has often been quoted that with males, if all else fails, refer to the handbook/instruction book/map etc. Seems it might cross genders as well. Obviously no offence Vanessa - join the club.

Automatic stop/restart functions. New fangled concept? Not really, these were fitted to some cars in the 30's to automatically restart them if you stalled. Much disrespected then! 

Good luck with it- or perhaps consider switching it off. 

Kind regards,

Gareth.

[Big_dom91]

Iv had similar problems with my 13 plate manual nd when it has happened it displayed a message saying stop start system disabled restart engine manually or something along those lines but its a very rare occurrence hence why I haven't been to audi with it.

[Vanessa]

Hi

Thanks for all the replies, very much appreciated. My car is now, once again, with Audi, and will be for a while, I have been given yet another courtesy car. My Audi yet again popped up with the start/stop whilst I was driving at 60mph, and had to brake to slow down briefly, it was not a happy moment!

I have had a lot of Audi cars over the years, and I have never had an issue with any of them, barring the one I have now, and this includes all the courtesy cars that I am driving at the moment.

 

[Envy]

Any update Vanessa? Intrigued to find out what the issue was.... 

[Jennyhen777]

Hello, 

I recently purchased a 2015 A6 Avant which has stalled three times at 40mph but the Audi dealership can't fault it. It's only happened on a straight road so far, dreading the time it happens on a corner...

Has anyone got any updates at all about this as dealership not being very forth coming?

[Envy]

Hi Jenny: As you can see - no-one has really come back to the forum with any information / progress regarding this possible issue with their car. When the engine cuts out (stalling is caused by overloading) can you recall what you were doing regarding controls input. Throttle on / throttle off. Braking? I see you have your drive selector in economy - is this always the case or just in the picture? Mine will stop its engine coasting up to stopped traffic but not above 10MPH.

When it cuts out does the rev counter go to "ready" or "off"? If we can find a common factor when the issue occurs this will be of use to any mechanic trying to diagnose the issue. 

My best advice is to keep on to Audi regarding the matter - you are approaching the end of normal warranty for the Car - this should be sorted as part of that original manufacturers cover. 

 

[Jennyhen777]

Hi Tom,

Many thanks for replying. The car has reasonable heating controls on at the time of happening as well as the radio but that is about it. It seems to happen when throttle off but not sure if coasting has been engaged as all of a sudden the warning sound/message comes up with manual restart required. The rev counter goes to Off as in the picture and yes I do have it in Economy mode at all times. It's happened 3 times at this speed over the course of 4 months which makes it extremely hard to find the fault as it's so inconsistent, therefore the dealership couldn't find anything wrong the first time but they are having it back again. I've got one year of the warranty left as was registered in 2016 so I'll certainly be continuing to get this sorted as it could be very dangerous. 

[Envy]

Hmm - with the car in Economy (Efficiency) mode, when you throttle off the car goes into coast mode effectively putting the gearbox into neutral allowing the car to free wheel at what should be tick over engine speed. With the gearbox in neutral there is no drive back through the geartrain from the wheels to maintain engine idle. 

This could be where the issue sits. If it were me with the Audi overalls on I would be looking at sensors and settings around engine idle control.

The next question would be does the fault happen in Auto drive mode? I tried all drive modes when I first got mine and it sits in Auto Drive Select most of the time now with no perceivable difference in economy. I concede this is not a fix but could be a work around of sorts

[Jennyhen777]

I'll certainly pass that on but I'm not sure whether the coasting function has cut in by that point or if I have braked at all then the coasting function wouldn't activate any way. All these times were completely unexpected and therefore not really paying much attention unfortunately but as I do now, chances are that it won't happen again. 

I've tried switching off the auto stop/start in case that has anything to do with it but haven't tried Auto mode yet. I fear that as it is so sporadic and rare, it will take me a very long time to be able to tease these things apart and I don't want to be in an accident as a result of it. If they can't find a problem then they can have the car back. 

[Jennyhen777]

Hello All, 

Just a quick update that the car has been back to the dealer and after contacting Audi Technical, it has hopefully been fixed by replacing the fuel rail pressure sensor and repairing the wiring harness. This is a problem known by Audi through TPI and it has also occurred on VW Tiguan's too. 

If you come across this problem, leave the car with the dealer until a ticket to Audi Technical is issued so that the diagnosis can be completed properly.

[Envy]

Hi Jenny - glad you got a fix - maybe Vanessa read the same if she has not already had it sorted. 

Time to get back to enjoying the car again.

[Jennyhen777]

Thanks for your help Tom.

I certainly will, nice to be out of the Q5 they lent me!

[Danny_021]

Hi All. Iv been reading through these posts and it seems I have a similar issue. 

I bought a 2015 Manual A6 Avant TDI 6 months ago and i am having issues with the car stalling but when it does stall it doesn't restart itself via the stop/start function, the car must be restarted by using the start button.

When I 1st purchased the car I thought it was me getting used to the car (even though I have driven allot of different makes/models and fuel types with hardly any issues) but recently my wife has been complaining saying that the car has cut out when exiting a round about whilst changing from 2nd to 3rd gear. This has happened more than once which with my 2 kids in the car is not safe. 

Reading Jenny's post above, could a faulty fuel rail sensor cause an issue like this? does anyone else have any insight as to what could cause the issue and also if it’s a known fault with Audi, could this be replaced by Audi even though it’s out of warranty? 

Thank

Danny 

 

[Petrol head]

On 1/23/2018 at 2:08 PM, Jennyhen777 said:

Hi Tom,

Many thanks for replying. The car has reasonable heating controls on at the time of happening as well as the radio but that is about it. It seems to happen when throttle off but not sure if coasting has been engaged as all of a sudden the warning sound/message comes up with manual restart required. The rev counter goes to Off as in the picture and yes I do have it in Economy mode at all times. It's happened 3 times at this speed over the course of 4 months which makes it extremely hard to find the fault as it's so inconsistent, therefore the dealership couldn't find anything wrong the first time but they are having it back again. I've got one year of the warranty left as was registered in 2016 so I'll certainly be continuing to get this sorted as it could be very dangerous. 

Hey Jenny,

What is your Engine model ?

Thanks,

Jose

[Jennyhen777]

Hi Jose, it’s the 2.0 TDI ultra.

And Danny, my other half was a mechanic at VW at the time and that sensor fixed the issue on all the models that had the same issue there too.

[Keith P]

Hi guys,

Would you believe I have exactly the same problem with my Audi A6 executive ultra 2.0 TDI which I bought only two weeks ago. When it first happened I thought it was just me getting used to the car but it has happened five times since I bought it. The most recent time from slowing down from 80k/ph and I nearly had someone drive into the back of me. I will be returning it to the garage next week and I would like to thank you all for the information provided here. 

 

Kind regards

Keith

[LP01]

Hi,

Have a A6 2.0 diesel from 2016, automatic transmission that was randomly stalling upon maneuvering (back a forth) or stopping at a traffic light. More often on slightly inclined streets.

It would happen twice or 3 times a month, and recently it was more frequent.

Received it today from the official Audi repair shop and apparently it was the fuel rail pressure sensor. Just drove a couple of miles, mas I could notice a big difference on the way the car behaves on stop ang go traffic. It stopped a light stutter upon bringing the car to a stop. Very, very smooth.  Some people say it is normal for a DSG to stutter a bit upon stopping but these cars are quite smooth (I guess the problem was growing slowly over time and I got used to it).

Just sharing because it could be useful to others. regards

(PS: I knew it had nothing to do with Start/Stop system because it is disabled since day one when I went to pick it up from the dealer)

[Petru Tasca]

Hi,

Have a A6 2.0 diesel from 2015 automatic gearbox.I will attach video to show how my car is doing🤔.(please watch till end)

From the beginning I thought it was the problem with the gearbox and I took the car to a service specialized in the repair of automatic transmissions,they made the diagnosis and said that the mechatronic unit needs to be changed and they changed it.

After I took the car and I drove the car one day and it did the same problem again so I took her back. 

After new investigations they said that the camshaft sensor needs to be changed and they changed it.

I took the car again and on the same day it caused me the same problem. 

My question is could a faulty fuel rail sensor cause an issue like this?

[Anton8]

Hi 

My stop/start does come on very early sometimes, even before stationary. Very disconcerting as you lose the power steering as well, but when I got used to it doing this a quick blip on the throttle was all that was needed.

Tony

[BigTownz]

On 3/11/2021 at 8:10 AM, Anton8 said:

Hi 

My stop/start does come on very early sometimes, even before stationary. Very disconcerting as you lose the power steering as well, but when I got used to it doing this a quick blip on the throttle was all that was needed.

Tony

I have also found this with mine. I just ensure I turn off the auto stop feature everytime I drive as I cant stand it. Its borderline dangerous as its always as reaching a junction.