Bought a 2012 A3 Petrol end of Jan, and at the end of Feb car wasn't turning on. Long crank and then doesn't turn on. Car works fine for short journeys but seems like when the car runs for longer than 25/30 mins and I turn it off, it won't turn back on for another few hours. Three times the car stopped working mid-journey. It loses speed and eventually stalls and turns off. 

Changed coolant temp sensor, crankshaft sensor, throttle body but none of these are fixing the issue. The computer diagnostic system says the below but despite changing the throttle body, these errors are still coming up. Also checked for fuel issues but all clear

• Throttle control unit malfunction
• Throttle actuator electrical & mechanical fault

Could this be an ECU issue? I found this online (attached) and the symptoms line up pretty well but have been quoted nearly 1k to diagnosis and repair if this is the case. Could this be done cheaper or is this the going rate?

Does this also even sound like an ECU issue? Car runs perfectly otherwise so my gut says yes but wanted to get thoughts

Could be the ECU and the only way you'll know is sending it off for repair. 

You might be able to buy a second hand one from eBay but it must be the exact same part number. Then the imobiliser will need to be removed from it or recoded to work for your car. 

Really struggling to find the exact same part number anywhere in the UK, seems like they're all from places in the EU. I found this plug and play one, but does this look legit to you, I'd send them my old ECU, they'd copy it onto another used one (same part numbers), and I can 'plug and play'. 

https://www.cartechelectronics.com/plug-play-siemens-engine-ecu-audi-5wp4078901-5wp40789-01-06a906033pa-06a-906-033-pa-simos-7pp/

Sounds too good to be true, but wanted to see if it actually is a trustworthy solution!,

 

Thanks

Edited March 28, 20242 yr by tuba
Forgot to add the link!

In your postion I would ask first the company what sort of guarantee it offers.

7 hours ago, tuba said:

Really struggling to find the exact same part number anywhere in the UK, seems like they're all from places in the EU. I found this plug and play one, but does this look legit to you, I'd send them my old ECU, they'd copy it onto another used one (same part numbers), and I can 'plug and play'. 

https://www.cartechelectronics.com/plug-play-siemens-engine-ecu-audi-5wp4078901-5wp40789-01-06a906033pa-06a-906-033-pa-simos-7pp/

Sounds too good to be true, but wanted to see if it actually is a trustworthy solution!,

 

Thanks

Hi the trustworthy solution is get in touch with ECU Testing and get it tested, no problem there is only a nominal charge, if there is a problem they will inform you with a repair price. Plus being as its your original unit its plug in and play.

Steve.