Start/Stop system fault

D-Lat

Registered User
Anyone else seen this?

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cuke2u

Registered User
Nope, I guess following the instructions is in order?
 

Happy Grumpz

Well-Known Member
Silver Supporter
Maybe a stupid question, does it do the same in the other drive modes?
 

Concerned Cat

Age & treachery will always overcome youth & skill
I'd be delighted if it wasn't working. It's the first VCDS mod I'll be making next week when it arrives!
 

steve.r.p

Registered User
Referring to the stop/start system failure , I've had this error occur several times since buying the car from new (September 2017)

It's been in the workshop twice . Both times all they have done is clear the errors (p060600) relating to the pcm.

Apparently Audi know of the problem , (apparently there working on the fix) and I've got to wait for them to contact me . Or Maybe it's a polite way off saying "live with it"
 

D-Lat

Registered User
I’ve only had it happen to me the once but not again since.

Also had the car since September 2017.


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RB84

Registered User
Guys, did you ever get this sorted? My S4 has just started doing it. Was new in October 2017, so coming on a year old and 10k miles. Not had any issues until this. Fan running even when driven normally and the Start/ Stop function malfunction warning flashing up like above.
Have asked to get it booked in ASAP
 

RB84

Registered User
My car is into Audi today, being looked at now. Tbh it isn't running well - quite a rough idle, fan on full as soon as you start the car up, temp at 100c, when I think it usually hits 90c, emissions warning light on amber and the auto stop/start malfunction being notified on the screen. Will see what's up with it!
 

RB84

Registered User
An update on my specific experience: diagnosed as faulty thermostat and they also replaced thermostat seals and crankcase seals. Now running well again. Audi Camberley got me into an A7 55 TFSI for 1.5 days, and an A5 2.0TDI S-Line for 1.5 days whilst mine was being sorted out. They also topped up the engine oil alongside the other work. All in all a frustration but they dealt with it well
 

ub7rm

Registered User
Interesting, mine has started to display same symptoms today a well. Going to call Audi assist.
 

cuke2u

Registered User
An update on my specific experience: diagnosed as faulty thermostat and they also replaced thermostat seals and crankcase seals. Now running well again. Audi Camberley got me into an A7 55 TFSI for 1.5 days, and an A5 2.0TDI S-Line for 1.5 days whilst mine was being sorted out. They also topped up the engine oil alongside the other work. All in all a frustration but they dealt with it well
Crankcase seals replaced sounds onimous, surely that would have necessitated draining the sump of oil?
 

ub7rm

Registered User
So this morning did a 10 mile drive and after a few miles the warning above came on about stop start function being unavailable. Thought that was odd but not too ominous, when I got to my destination I realised the fans were running full pelt and the temperature gauge was lit up one notch above the 90 mark. I have never see it above 90 even on a hot summers day after a hard run so alarm bells started ringing. The oil temperature was OK though at 70 deg approx. Made the journey home and called audi assist (AA) who were there in half an hour.

By this time the engine had cooled and the stop start system was normal. Two fault codes, 11786 and 8113 - but no explanation available for what they meant. Couldn't replicate the temperature rise or stop start system fault even after a test drive and leaving the car running for 20 mins.

Car ran perfectly throughout apart from the fans running.

He left the codes stored, but since no warning lights or error messages were displayed and nothing physically amiss there was nothing else he could do apart from say to take it to the dealer on Monday.

The chap did explain that if any of the normal parameters are out of bounds then the first thing the car does is switch off the stop start system and switch the fans on.

@RB84 did the fault start out intermittent and escalate?
 

ub7rm

Registered User
Further update, went out on another run, temp climbed one notch above 90, orange engine management light came on this time. Noticed that even on max the air coming out of the heater was not that hot. Got home and the fans were running fast but the whole engine bay felt cold. Indicated oil temperature was about 60. The expansion tank for the coolant felt tepid at best. The only indication of any form of 'overheating' is the temp gauge.
 

cuke2u

Registered User
I would suggest you stop driving it and call out Audi Assist and tell them you cannot continue to drive the car and risk further damage...
 

ub7rm

Registered User
Yes the car is now 'grounded' until I can get it into the dealers. We're on holiday from early Monday morning so this is a pain in the **** to put it mildly. All the evidence suggests an open thermostat since there is heat reaching the cabin but not as much as usual - except the slightly elevated water temperature shown on the gauge. Oil temperature was struggling to get above 60 and often fell below that.
 

RB84

Registered User
Further update, went out on another run, temp climbed one notch above 90, orange engine management light came on this time. Noticed that even on max the air coming out of the heater was not that hot. Got home and the fans were running fast but the whole engine bay felt cold. Indicated oil temperature was about 60. The expansion tank for the coolant felt tepid at best. The only indication of any form of 'overheating' is the temp gauge.

This is the exact issue I had. One notch above normal i.e. 100, fan on full blast as soon as you start, auto start/ stop fault flags up and the amber emissions light on. Mine came from nowhere to being on all the time - no intermittence, but it did happen on a 90min, 80 mile drive, so the fault may have been more intermitent if it had been more smaller distance drives in that time.
I'd suggest it's the exact same issue and they did reference a TPI on my Audi paperwork. This is their exact wording;

Carried out investigation into EML light on. Ran guided fault finder and found multiple faults stored with cooling system. Found relevant TPI instructing to replace thermostat. Replaced seals and thermostat, re assembled charged cooling system and bled. Tested ok.

I hope that's of some use. Sorry for being slow back onto the forum - didn't get any email reminders of posts which I was expecting.
 

ub7rm

Registered User
Thank you, I agree it seems likely it's the same issue .Will update when it's been diagnosed and fixed .
 

cuke2u

Registered User
Is there a TPI number, is this the same as a TSB?
 

ub7rm

Registered User
Car went in this morning, diagnosed as a faulty thermostat per the problem that @RB84 had. Got it back tonight. They sent me a video of the faulty thermostat and it showed that it had basically warped - open on one side and closed on the other.
 

Filipão

Registered User
Thanks, but not really. Still there and they're going to change the 3 temp sensors.

Boy, I miss my S4 Tdi already!
 

Filipão

Registered User
Thank you @ub7rm.

The problem is chief mechanic was reluctant to accept the diagnosis and wanted to check first behaviour with new sensors.

Now he's convinced and a thermostat has been ordered. I've lost 4 days of my short life!

P.S. Didn't manage to see the video, would love to forward it to the Dealership.
 

RichardMMM

Registered User
I've only just seen this thread but I had the same issue in early October, the engine fans on full all the time and the engine warning light on (and the start/stop message). Like others it was a faulty thermostat. Audi assist were excellent, they got the car towed to the garage and arranged a Enterprise Rental Audi for a week.
 

Peter Huggon

Registered User
I’ve just had the same fault this week. I could hear the fan on flat out and then realised I had a grey warning triangle on the VC tabs ... Start/Stop not available. I phoned the garage next morning and they said there was nothing urgent they could do as there wasn’t a red or amber warning light. They offered to book me in for next Monday but couldn’t provide a courtesy car. Set off for work and a few miles later the amber engine light came on. I returned home and phoned the garage ... they then told me to phone Audi Assist as they couldn’t do anything until the fault had been diagnosed.They also told me that Audi Assist would arrange a hire car. Great I thought, how convenient. Audi Assist turned up and diagnosed the fault as the above issue and the technician explained that the thermostat was sticking partially open which the car detected because it took longer to warm up. He also told me that the fault had occurred 12 months ago but because there wasn’t a tech bulletin at that time it looks like a correct repair hadn’t been carried our ... slightly worrying.
I then spent the rest of the day waiting for the Audi garage (not Audi Assist) to arrange the hire car ... what a shambles! I finally found out at 4:45 (5 hours after the email had been received by the garage) that they had a car available but couldn’t deliver it till this morning. So I drove to work this morning then took it across this afternoon. Oh well, at least it’s in the garage now. Hopefully get it back next week ☹️
 

cuke2u

Registered User
Fingers crossed, seems to a lot of these 'just a batch' of them...
 

ub7rm

Registered User
At least they are failing in the partially open mode and not stuck shut - that could result in a new engine being required.
 

Filipão

Registered User
@Peter Huggon please make sure they will bleed the cooling system afterwards.

On mine, they did NOT. It was Friday evening, I needed the car fast and they drove test it and then handed the car over to me directly.

I had to fill in the expansion tank Saturday morning first thing on starting engine, with the amount of anti-freeze lost during thermostat replacement.

No comments.
 

cuke2u

Registered User
****** amateurs, could quite easily have wrecked your engine. Never allow for a job to be rushed, even if the customer is impatient ;-)
 

ub7rm

Registered User
Perhaps @D-Lat would be good enough to change the title to start stop system fault - Thermostat. As I understand it whenever the ECU detects 'anything' out of normal operating parameters it switches the start stop system off - so likely this warning is a precursor to multiple issues.
 

Filipão

Registered User
Perhaps @D-Lat would be good enough to change the title to start stop system fault - Thermostat. As I understand it whenever the ECU detects 'anything' out of normal operating parameters it switches the start stop system off - so likely this warning is a precursor to multiple issues.

Absolutely. Please do so, @D-Lat
 

DreR

Registered User
I have 2018 S5 sports back and just past 14,000km. Yesterday Audi put on the winter tires and also topped up the oil and washer fluid. Today while driving I get the same error message - yellow malfunction indicator lamp (MIL), start/stop failure message, temp gauge going over 90c and the engine fan on full.

Can this be just bad luck or did someone at the garage mess something up?
 

hellodave

Registered User
Sorry for bringing back a thread from the dead but this happened to my 2017 S4 today - 12K miles, fan running on full from engine start, start stop fault, temp a notch above normal and check engine light on.

I called Audi Assist who diagnosed a bad thermostat and had it recovered to the dealer. I await their verdict on Monday!

It seems this is a common fault but the Audi bulletin still states it is "under investigation" i.e. "we still don't know what causes it". It advises dealers to take photos of the bad thermostat and seals before returning the faulty parts to them.

Has anyone had the fault reoccur after having it fixed?
 
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