B9 S5 - Cooling Fault Codes / Brake Fault

[Stim]

Hi folks,

I'm looking for some advice with a recent fault I've had with my S5 (B9).

The car has been sat on the drive for the past couple of years mainly due to COVID and the fact that I now primarily work from home.

I took it for a short trip into town and after switching on the engine on my return trip, I had a couple of faults appear.

The first was "Brake Servo Restricted"

The second was "Start/Stop system fault. Feature unavailable. Contact your workshop"

The car was due for it's service and oil change, so I took the opportunity to call the garage to get it booked in. On top of the service costs, they wanted £150 just to look at the issue.

I did some Googling and it appeared as though it was a failure of the brake pressure sensor as a number of other drivers had the same issue. It only took me a couple of minutes to swap it out. After doing so it cleared the immediate fault.

The car went in about a week later for the service and when the garage carried out their health checks, they told me it had multiple coolant warnings and would need further investigation. There was no indication of a fault on the dash prior to this. They wouldn't disclose anything more than that it had multiple faults, but after I did some digging I've found the following fault codes active on the system:

G694 - Temperature sender for engine temperature control

G62 - Cylinder Head coolant temperature sender

G82 - Coolant temperature sender at engine outlet

On top of this, on the ride home from the garage the "Start/Stop system fault" appeared again. No "brake servo restricted" message this time.

I'm worried now that it's actually a much deeper problem with the car. Does anyone have any thoughts on this and where I should go with it?

Following their recent discovery, the garage now wants £360 to investigate the fault further as it they inform me that they'll need it for a good 3-4 hours to remove a lot of the front.

 

[Stim]

Looks to be in relation to a faulty thermostat.

https://static.nhtsa.gov/odi/tsbs/2020/MC-10176410-0001.pdf

I'm going to see if I can get a quote for work done outside Audi given that it's no longer under warranty.

[Steve Q]

On 7/1/2022 at 3:25 PM, Stim said:

Looks to be in relation to a faulty thermostat.

https://static.nhtsa.gov/odi/tsbs/2020/MC-10176410-0001.pdf

I'm going to see if I can get a quote for work done outside Audi given that it's no longer under warranty.

Please keep us posted on how you get on 🙂 

[Stim]

I've had a quote locally for £434 all in for the full replacement of the thermostat, coolant and seals. It's booked in in a couple of weeks.

[Magnet]

Hello Nope ( really!?) 

One simple two word component to check before spending anything:-

            Battery efficiency. 
Kind regards,

Gareth. ( real name) 

[Blueit]

HI, i HAVE JUST EXPERIENCED THE SAME WARNING MESSAGES RE- BRAKE RESTRICTED ON MY ADUDI A4 TFSI 1.4 2017  CLEARED ITSELF AFTER ACOUPLE OF DAYS.

HOWEVER, ENGINGE STOP START RESTRICTION APPEARED SHORTLY AFTER. AND MY CAR HAS NEVER STARTED SINCE (2 DAYS)

i HAVE FOUND THAT I HAVE A PETROL LEAK ON THE FUEL RAIL HOUSING, DON'T KNOW WHAT IS CAUSING AS YET.

i THINK THERE MUST BE A SEAL ON THE INSIDE THAT MAY HAVE PERISHED ( i THINK I'M LOOKING AT COSTLY REPAIR, AS i'M SURETHE MANIFOLD HOUSING ETC. WILL HAVE TO BE REMOVED TO ENABLE REPAIR.

UNLESS ANYONE KNOWS BETTER...