Reavley

I was planning on adding to the forum at the point there was something worthwhile to update the forum on. I didn't see the point in messaging regularly to say nothing new to report. Thankfully the warning has only appeared in few and far between instances recently. As noted above it only tends to be when starting the engine when already hot (after popping into a shop etc). Whilst I don't think the issue is gone, I have been very busy recently and dealing with the car has not been a priority. I am following the advice of my local mechanic and seeing how things go for now before deciding upon the next steps.

I appreciate all the contributions in response to my post. And I take the information provided into consideration in the decisions I make. I will provide an update as an when there is new information to share. You don't need to try and prejudice what I may or may not do with my car.

I haven't added an update as I don't have an update to provide at this point. Nothing has changed since my previous post.

I trust my local mechanic far more than I do Halfords

I took the car to a local mechanic. He was not concerned with what I thought might be a low voltage at the battery terminals whilst the engine was running as he said the car has smart charging which involves varying voltages. He ran a diagnostic and could see some warnings relating to something along the lines of an electronic turbo control unit (can't remember the exact name. I have the diagnostic report printout but not with me right now). He reckons it would be £300-£400 fitted incl VAT. He cleared the warning light from the dash and suggested I see how it goes before making a decision on what to do. Unfortunately I have been getting the drive system fault dash warnings since. But interestingly it has been manifesting a little differently. Previously the warning would tend to come on part way through a journey. But recently it has tended to be when turning on the engine ignition whilst the engine was already warm from a recent drive. I haven't yet had the warning whilst starting the ignition from cold.

Apologies for the ambiguity Gareth... I did indeed mean engine running when I said engine on. I'm no fan of Halfords but I have messaged a local independent mechanic, who I've used in the past and had positive experiences with, to book the car in for him to look at. I note Cliff's point about having the battery coded to the car and will ensure if I do end up needing a new battery I will make sure it is somewhere that can code it to the car. Really appreciate your notes on a potential belt or alternator Davey. Handy to have a few potential causes in mind when the mechanic gives their opinion.

Thank you Davey

Thank you both. Would that be 14.4v straight after turning the engine on or does it take some time to build to that? The 12.9v I got with engine on was straight after ignition. Thank you

Hello, I have a 2017 B9 2.0 petrol. I've recently had dash warnings the start/stop and drive system fault. The first few times the faults cleared with turning it off and on again. But now the engine dash light is permanently on yellow. I will take it to a local garage for a diagnostic but wanted to have a bit dig myself too. I saw it could be an issue with the battery so thought I'd test the voltage with a cheap multimeter I had. The readings I got were 12.5v with engine off, and 12.9v with engine on. Are those readings ok or could there be an issue with the battery? Cheers Martin

It is a real shame Audi can't do the right thing and admit there is an issue. If they had a recall and replaced the old faulty sensors the next time a car was in for service it would be a relatively cheap solution in my opinion. It has shaken my trust in the brand from a quality side as it is poor to have faults on newish cars, and also a customer service side when they don't correct their own mistakes. I don't think my next car will be an Audi as a result of what should be a minor problem to fix. Shame on Audi.

I emailed Audi UK to ask if they could provide me with the service schedule/intervals. After some back and forth I have been told that Audi UK don't have that information and it sits with the dealerships... I find it laughable that the manufacturer would try have me believe they don't know the service intervals of their own cars. It feels like they want to make it as hard as possible for owners to have their cars serviced outside of the dealership network. It does nothing positive for my thoughts about owning another Audi in the future. After previously owning a BMW for which the service plan covered all service items I am not a fan of Audi's service plan not even covering brake fluids neither.

Hello. I have a 2017 Audi A4 2.0 petrol automatic (A4 S LINE TFSI S-A). I am looking for a schedule that outlines the various service items and intervals for my car but after googling and speaking to the service center at my local dealer I am struggling to understand exactly what service items are due and when. Does anyone on here know if there is a service schedule for the A4 specifically, rather than a generic audi fleet one? Thank you Martin

I have been to Audi Newcastle this morning and picked up the new sensor, part 5Q0906207B. I have fitted it and both the restricted servo and start/stop dash warnings have gone. I haven't had a chance to drive the car since but fingers crossed my issue is now resolved. Whilst speaking to the guy who works in the dealership Parts department he said they keep stock of the sensors and are selling multiple units a month. He even said he recognised the part number when I quoted it over the phone and instantly knew which part it was which is a statement in itself. He said it is a known issue but not considered common. If each dealership is selling multiple units a month on cars that are still relatively young, and especially considering the cost of ABS repairs if not resolved swiftly, I would say that is a common issue that needs more attention from Audi. The guy also said they have a car in their shop at the moment getting the ABS repairs as the car was driven after the initial restricted servo warning came on. So that is another fellow Audi driver who is about to take a large hit to their wallet for an avoidable problem. Shame on Audi!

Thankfully I can work from home so my intention is to leave the car on the drive until I can get my hands on a replacement sensor. Hopefully a new sensor clears the dash warnings but if not I'll book it in at the garage.

I have a 2017 A4 saloon 2.0 petrol. The brake servo restricted light came on 2 days ago but I didnt get around to researching it until today as I felt secure with the dashboard message saying it is ok to continue driving. Turns out that is a false sense of security and I wish I had looked up the issue earlier but I'm hopeful that I can still get away with the simple sensor replacement. After ringing around the 3 local dealerships in my area one said another has stock (same company with multiple dealserships) but annoyingly the parts department at that dealership haven't been answering my calls all day! It sounds like the part number has recently been updated to have a B at the end rather than the A I had seen on earlier threads. I believe the part number for the sensor is now 5Q0906207B. I will try contacting the dealership again tomorrow. Fingers are crossed... This is my first Audi and I am very disappointed that it feels like Audi have their eyes closed (deliberately or not) to a simple and cheap fix that could save owners £ thousands. At less than 4 years old I had no dreamt that I could be on the line for such a costly repair, made only worse when I read how common this fault appears to be.