Engine cuts out

[Anton8]

This is worth remembering.

[beemerboy9]

On 3/18/2021 at 6:16 AM, BigTownz said:

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.

I have had my Stop-Start coded out (via a third-party) using VCDS so that it does not come on automatically the car is started. 

[Petru Tasca]

Hi,

I have a A6 ultra S-Line 2.0 tdi from 2014 automatic gearbox.

My question is could a faulty fuel rail sensor cause an issue like this.(please watch the video)

[Jatman]

Hello All,

I have an 2014 Audi A6 with exactly the same issue. I took my car to kwick-fit to test the battery, the readings were all clear. Then I took the car for a service / MOT at a separate garage and ran an electronic test, they found a few error messages on the computer.

When I was holiday, the cars  power closed down, literally had no power, no electronics, had to open my drivers door to activate the electronics, pressed start / stop and the car restarted.

Today when to school at 16:20, parked up, the cars whole power system shut down.  Couldn't power on, no lights, couldn't lock the car, zilch. Went into school, got the kids, they had to climb through the drivers door as there was no power to the car. Waited till 17:00 till power reset itself in the car. Then drove home.

So in mine the start / stop system shuts down the whole electrics to the car. I have the car set to dynamic mode, the issue happens at low revs. It's hard to replicate as it's random, but my does shut down and I can't restart all the time, making it dangerous to sit in.

Need help fast please.

Thanks.

Edited October 19, 2021 by Jatman

[Magnet]

Hello Jatin,

My money would be on an unserviceable battery - despite what Kwik Fit tell you. I’m pretty certain your car is fitted with a Battery Condition Monitor (BCM) and this is continually monitoring all parameters of the battery’s efficiency and will start to shut down various features, as the battery becomes deficient in any monitored parameter. Probably, Kwik Fit’s test was a basic check. 
The batteries on Stop/Start equipped vehicles obviously get a hammering, and can deteriorate at a rate of knots. 
Your car is 7 years old, and it would be surprising if the original battery has lasted that long, and not impossible that it has already been replaced, and that one is now failing. 
What make battery is fitted to the car Jatin? That should give you an indication of whether it is the original or not. 
A couple of points, if you do decide to renew the battery:- 

Buy once and wisely, and certainly not on price. I buy Varta/Bosch ( their 4 or 5 year warranty variant) from specialist on-line battery suppliers such as Battery Megastore or Tayna ( there are more - search eBay for best deals on these). 
Double check the correct battery you need by giving the supplier your registration number.
It is highly likely that the new battery will need to be coded to the car - otherwIse the system will assume it’s still the old battery.

Kind regards,

Gareth.
 

[Anton8]

Hi

I thought the stop/start function was run using a large capacitor, which is recharged via the  alternator using engine power. I didn't think the battery was involved in this function. This is why the stop/start seems to be random because it relies on the charge in the capacitor not the battery. Perhaps the capacitor should be looked at.

Tony

[Stevey Y]

Hi possibly the BEM module gone up the wall its a fairly simple task but I believe a new one will need re coding, have you had your car scanned for faults?.

Steve.

[salliedollie]

Hi everyone,

I have a 16 plate Audi a6 avant 2l, had it for a year now. I drive in economy mode 90% of the time and have the start stop on. The start/stop is quite sensitive I find at times, but when I stopped at a roundabout today the whole engine cut out and when I took my foot off the break, the engine would normally turn on again and it didn’t. I have to put it in to park, parking break on, hazards on and press the start button 5 times for it to come on again. The car was making a turning over sound as if you put a key in the ignition and turn it as far as you can to the right and hold it there. 
Does anyone think fuel rail sensor or something different? I have turned off start/stop in the hope it will not do it again.

thank you! 
also comes up with ‘start-stop system deactivated. Please restart engine manually’