Q7 3.0TDi 2011 ECU/Throttle Circuit fault plus oil/injector seals

[colbry]

My Audi Q7 3.0TDi showed a engine fault (flashing glow plug icon) and Stability Program warning message on dash display. VAGCOM diagnosis at secondary service garage showed Throttle Position Sensor Circuit (TPSC) fault traced to pedal sensor and DPF needs regenerating (no DPF warning on dash display). Wouldn't allow regen without pedal replacement.
Pedal and sensor replaced and ran without problem for a few weeks then engine fault and Stab Prog warning again.
Took it to Audi main dealer for diagnostic. TPSC fault plus ABS and Suspension, plus rear offside passenger door lock and offside AC fault listed all with similar Unlearning Counter/Drive Cycle numbers (215-255) - (does this mean they all stared at the same time???) Do they all share a similar wiring loom/connector?

Drove car away to follow-up with first garage but broke down within a mile or so - no throttle response - would creep along on tickover.

Recovered to Audi - who checked out the TSPC and now say it is the ECU that needs replacing.

However, main cost is oil leaks from rear casing and sump and at least one injector seal - requiring engine out and full reseal.

Are the seal failures due to back pressure from a blocked DPF/oil pump/whatever???

2011, 90k miles, owned by me 4 years bought from Audi main dealer as approved used car - obviously out of warranty now.

Any guidance before commissioning work would be appreciated!!!

[Joe2.0E]

Not sure on a Q7 but the 3.0TDI engines on A6,A7 & A8 models from 2011 approx onward are prone to oil leaks from the middle sump usually at the rear of the engine.
Engine out to fix ££££ but it's a known issue and Audi have paid 50% - 70% of the bill in the past if you have a FASH.

[colbry]

I thought that might be possible - but I need case references to push it. My dealer wont pursue it with Audi because I had my last service done out of VAG - but it was done with Audi parts and correct spec oil with receipts. However I can get it done by a reputable, recommended VAG specialist at half the price of Audi so for this age car it might not be worth the hassle of fighting Audi for it. The injector seals can be done at the same time - at half Audi main dealer rates, and I think I can get the ECU tested/repaired by Bosch through the same workshop for around £100 rather than £1600 from Audi for a new one.

Audi modified the rear casing seal in April 2013 and knew there was a problem with it.

[colbry]

After recent very cold, wet, weather ('beast from the East'), got a bunch of warning lights and fault codes including 'throttle position sensor circuit', 'stabilization program', 'automatic suspension' and a couple of other random ones. Audi eventually diagnosed ECU failure - and the throttle died on me driving home from diagnosis - rapid deceleration to tickover when pulling on to a roundabout.
Got the ECU replaced at a cost of £1600.

Opened up the ECU and found a small amount of corrosion internally around the vent plug and a corresponding spot of corrosion on the circuit board immediately below that point.

The perimeter sealing is very strong but the vent plug is not an air-tight fit because there is an atmospheric air pressure sensor in there.
Uploaded photos showing vent plug corrosion and close up of Circuit board damage. Bosch couldn't repair it.

2 short video clips at:

Audi Q7 2011 3.0tdi ECU - YouTube
Audi Q7 2011 3.0tdi ECU part 2 - YouTube

ECU circuit board corrosion under vent.jpg
ECU casing int corrosion around vent.jpg