Flashing Traction Control light

[TTS_DaveK]

Hi, I’m new to the group and have a plaguing problem with my 2017 TTS (I’ve posted here aswell as the TT forum being the same engine as S3, sorry if I shouldn’t have).
It has a stage 1 ECU/TCU from Unicorn Motor Developments producing 376bhp. I purchased the car with maps already installed in 2021 and the car was rapid quick , the TC light barely ever flashed in the dry under hard acceleration and pulled like a train.
Fast forward to March 2023 it had its big 40k service at Audi. It also had 4 new tyres (Bridgestone Potenza). When I got car back I started to notice fairly quickly the TC flight was flashing under hard acceleration which it didn’t do before, turn TC off and feels like it’s the fronts spinning. Thinking new tyres could need scrubbing in left a couple of weeks running in but it was still doing it. I was convinced it was then the Haldex pump knowing Audi had serviced it but probably not extracted it and cleaned. I phone Audi back up and explained problem but was told 6 week wait to book back in just to look at it! So I took to my local Audi specialist instead who plugged it in to VCDS but could find any faults in system. They then took pump off and the gause and inside pump were very clean. He also said he could hear the pump working under car on ramp so doesn’t think it’s the pump. He suggested contacting Unicorn as thought maybe Audi have removed one/both maps causing this to happen but I cant believe a standard TTS/S3 would spin that much under hard acceleration with around 70hp less then I have but I’ve never driven standard one to compare.
I’ve got no idea what to try next. Hoping someone here would possibly have any ideas? I’m still not convinced the haldex pump isnt working correctly, it has all the symptoms. But there’s no faults on the AWD system so is that even possible?

 

[NHN]

I would ask the dealer if they did any updates to the car whilst in, get the odis logs to prove it as it may have been updated on the box & not engine & thus maybe why it's doing as it is, I dont know the maps, but Mr unicorn is well regarded, did you chat to him yet.

 

[TTS_DaveK]

I would ask the dealer if they did any updates to the car whilst in, get the odis logs to prove it as it may have been updated on the box & not engine & thus maybe why it's doing as it is, I dont know the maps, but Mr unicorn is well regarded, did you chat to him yet.

I did wonder if this could be the case tbh. That would make sense why it won’t stop spinning now. I have tried calling a few times but not managed to get through yet. I have messaged on Facebook so just hoping he has time to reply.

I think next port of call is to go back to Audi tomorrow and try and get Odis logs.

 

[TTS_DaveK]

I would ask the dealer if they did any updates to the car whilst in, get the odis logs to prove it as it may have been updated on the box & not engine & thus maybe why it's doing as it is, I dont know the maps, but Mr unicorn is well regarded, did you chat to him yet.

So been to see Audi this morning. They were about as much use as a chocolate fireguard. I asked if either software could have been mistakenly removed on service where he told me “we only plug it in Odis to do diagnostic check not update software, and only carry records for 30 days” they definitely don’t want to help. Only want to book it in for more diagnostics, couldn’t even give me a quote for that
So still non the wiser to what it is.

do you know if VCDS can read if you are running stock or stage 1 TCU & ECU maps when you plug it in?

 

[Harvey]

@TTS_DaveK my gut feeling is Haldex related especially as you say the fronts are now spinning. I doubt very much the dealer would have performed any software updates as my understanding is they won't update unless there is a problem reported. I would advise you try a different VAG specialist indy garage to try and establish the exact cause as the car should simply grip and go with a Stage 1 ECU+TCU.
Just a thought but I am aware of a former S3 owner @The Cardinal who had issues with his Haldex due to internal machining and had to use a shortened drain plug, more on that here.

do you know if VCDS can read if you are running stock or stage 1 TCU & ECU maps when you plug it in?

Depends who/how the map is done, most you won't be able to tell but some like TVS you will as they update component name in the VCDS scan like this TCU example "Component: TVS DQ381"

 

[TTS_DaveK]

@TTS_DaveK my gut feeling is Haldex related especially as you say the fronts are now spinning. I doubt very much the dealer would have performed any software updates as my understanding is they won't update unless there is a problem reported. I would advise you try a different VAG specialist indy garage to try and establish the exact cause as the car should simply grip and go with a Stage 1 ECU+TCU.
Just a thought but I am aware of a former S3 owner @The Cardinal who had issues with his Haldex due to internal machining and had to use a shortened drain plug, more on that here.


Depends who/how the map is done, most you won't be able to tell but some like TVS you will as they update component name in the VCDS scan like this TCU example "Component: TVS DQ381"

Hi, thanks for reply. All the symptoms are pointing that way and it did stop working the day it went in for its 40k service. I’ve since been to see my local Indy Vagtech. They are fairly confident they can get to the bottom of it through various mechanical tests if they can’t find anything through VCDS either. I’m just praying they can sort it.
So disappointed in Jardine Audi, and the aftercare provided. Definitely complaining to Audi customer service once I get to the bottom of this.

thank you again

 

[jojo90]

@TTS_DaveK I have the same issue with my S3, also around the 40k service interval, did you manage to resolve and if so what was the fix? Thanks

 

[NHN]

Yeah I'd be interested to know the outcome & that dealer isn't being truthful, it has been known for them to update modules even when in for services as it auto flags them that there are updates.

 

[TTS_DaveK]

Ok so I have an update but I haven’t resolved the issue as I believe it to be the clutch in the rear diff slipping. I had a brand new haldex pump fitted and new haldex oil about 6 months ago and made no difference. However on taking the car to QuattroTech they drained the haldex oil and found particles in it which is now pointing to the Haldex clutch in the diff is slipping. It still doesn’t throw up any errors on ODIS when they tried and I get none on VCDS 22AWD . I’ve noticed it’s extremely bad when hard accelerating from stop/slow speeds but nowhere near as bad if you accelerate from about 40-50mph upwards. Which would make sense as the torque load on the haldex clutch will be a lot more from standstill than when you have the momentum moving faster already. They assured me the rear wheels are working and the controller is also working ok. I don’t fancy £5k for a new diff so I’ve resorted to trying to find a decent used one at a decent price but I’m still looking. I’m having to turn the TC off if I want to “drive” the car but it’s always lighting up the fronts , pulling left/right before the rears finally get going but it can’t be doing it any good.

I’m also wondering if anyone know’s the difference between gen5 diffs, weather it be 2.0TFSI TT, TTS, TTRS, S3, Golf R etc. does anybody know if these are directly interchangeable with eachother (same part number) or is there differences between them? I’d assume the controller is different at the minimum.

Hope this helps and TIA if anyone can help me.

 

[alpesh26]

Ok so I have an update but I haven’t resolved the issue as I believe it to be the clutch in the rear diff slipping. I had a brand new haldex pump fitted and new haldex oil about 6 months ago and made no difference. However on taking the car to QuattroTech they drained the haldex oil and found particles in it which is now pointing to the Haldex clutch in the diff is slipping. It still doesn’t throw up any errors on ODIS when they tried and I get none on VCDS 22AWD . I’ve noticed it’s extremely bad when hard accelerating from stop/slow speeds but nowhere near as bad if you accelerate from about 40-50mph upwards. Which would make sense as the torque load on the haldex clutch will be a lot more from standstill than when you have the momentum moving faster already. They assured me the rear wheels are working and the controller is also working ok. I don’t fancy £5k for a new diff so I’ve resorted to trying to find a decent used one at a decent price but I’m still looking. I’m having to turn the TC off if I want to “drive” the car but it’s always lighting up the fronts , pulling left/right before the rears finally get going but it can’t be doing it any good.

I’m also wondering if anyone know’s the difference between gen5 diffs, weather it be 2.0TFSI TT, TTS, TTRS, S3, Golf R etc. does anybody know if these are directly interchangeable with eachother (same part number) or is there differences between them? I’d assume the controller is different at the minimum.

Hope this helps and TIA if anyone can help me.

Could you have your diff rebuilt with new clutch plate(s)?

Unsure if the link below is what has failed in yours but, if it can be replaced it takes all the guess work of compatibility out and probably costs less than a used diff you dont know the condition of. Unless the labour cost to rebuild is prohibitive.

Set of lamellas for 4th and 5th Haldex gen

Set of outer and inner lamellas (discs) of the 4th and 5th generation haldex clutch for VW, Volvo, Land Rover, Opel, Saab, Ford and BMW vehicles.

www.4x4parte.com