Audi A7 gearbox malfunction P179D

rihardsss

Registered User
Hi guys,
Month ago bought myself a shiny Audi A7 3.0Tdi S-tronic, year 2012. And shortly after got dreaded gearbox malfunction, you can continue driving. Checked faults and it shows P179D - Coolant Oil Valve Electrical Fault. Been looking for information, but got some different stories about what people did to resolve it. Anyone can help out with information? Or maybe can suggest someone who's experienced with this and is located around UK Bristol area? It's intermittent for now and can't really feel problems with gearbox, but from what I read if there's coolant leaking in wiring harness it could reach ECU. Would appreciate some help!
 

+robster+a7+tdi

Registered User
fortunately i have not suffered this but i have heard of egr coolant bypass spindle leak down engine down loom into tcu round plug causing all sorts of errors and this is the first thing to rule out.

i would imagine worst case scenario is a major gbox service including pickup filter and when your in there whip out the mechatronic and send away or ive heard there is a repair kit.
but ive used these guys for ecu and abs repairs before and always been sound

 

+robster+a7+tdi

Registered User
Ive got some bumf from my last repair
 

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rihardsss

Registered User
thats the smaller dsg ours are more robust hope its your plug is wet
Thanks for sharing! Decided to book in with Audi Bristol for diagnostics and see if they find it. After looking around on forums it seems like cooling valve is very likely to be causing this issue. Will see what Audi will say on Friday. Certainly want to act on this quickly. Surely previous owner already saw this malfunction message, so it could be going on for a while now.
 

+robster+a7+tdi

Registered User
just for your curiosities, i was under mine today and checked mine to be ok
 

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rihardsss

Registered User
just for your curiosities, i was under mine today and checked mine to be ok
Nice and clean there! I had my diagnostics and they didn't put it down as 'definite' answer but likely to be mechatronics unit and they quoted £1,7k for it. Think I'll pass on that. Considering to use ecutesting.com and send my unit for repairs. Only having issues with logistics about how to get it done, since don't have a ramp and don't know if it will be difficult to take it out/put it back in myself.
 

beemerboy9

Registered User
Hi guys,
Month ago bought myself a shiny Audi A7 3.0Tdi S-tronic, year 2012. And shortly after got dreaded gearbox malfunction, you can continue driving. Checked faults and it shows P179D - Coolant Oil Valve Electrical Fault. Been looking for information, but got some different stories about what people did to resolve it. Anyone can help out with information? Or maybe can suggest someone who's experienced with this and is located around UK Bristol area? It's intermittent for now and can't really feel problems with gearbox, but from what I read if there's coolant leaking in wiring harness it could reach ECU. Would appreciate some help!
You are so lucky to be near Bristol . Milta Technology are the DSG gurus.
 

rihardsss

Registered User
You are so lucky to be near Bristol . Milta Technology are the DSG gurus.
I didn't even know about them until now! I'll get in touch with them and see what they could offer. Not a fan of idea that I'd have to strip it down and leave my car on ramps for several days until ecutesting return mechatronics back. Thanks for mentioning them, will see if they are affordable
 

singhl

Registered User
I will vouch for milta, my 2015 a7 box failed, everywhere else wanted £3.5K + to fix, they did for £2.5k all in , not cheap, but the cheapest, and event 2 weeks out of warranty, I had a small issue (nothing serious) and they fixed it for free.
 

rihardsss

Registered User
I will vouch for milta, my 2015 a7 box failed, everywhere else wanted £3.5K + to fix, they did for £2.5k all in , not cheap, but the cheapest, and event 2 weeks out of warranty, I had a small issue (nothing serious) and they fixed it for free.
Monday will bring it in for their diagnostics. According to pricing only mechatronics is £1400+VAT. But if something else in there is worn out then will be more. How bad was your gearbox when you took it to Milta?
 

beemerboy9

Registered User
Monday will bring it in for their diagnostics. According to pricing only mechatronics is £1400+VAT. But if something else in there is worn out then will be more. How bad was your gearbox when you took it to Milta?
What was the outcome of the check by Milta?
 

rihardsss

Registered User
What was the outcome of the check by Milta?
They confirmed that need to recondition mechatronics unit. Just had it done by them and charged me 1200£. Sometimes clutch can go bad as well if there's trouble with mechatronics, but luckily mine was still good! They also said wiring loom to control valve wasn't delivering right voltage and had gone bad, which they replaced. But control valve itself was fine. On my way home gearbox did feel nice and smooth.
 
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