can't adapt new throttle body

[Meseburger]

Hello fellow A2 enthusiasts,

About 2 weeks ago I had a local shop install CC on my 1.4 petrol, right after they were done, we were gonna take it for a test drive, but throttle body lost its settings, so they readapted it quickly. Everything worked okay after that, I was really satisfied with the cruise control, money well spent. Right? Well I'm beginning to have doubts about that...

2 days later I was on a drive, passed over some railroads, I've probably passed over a million times so far, barely felt anything really, then came the beeps... ECP, ABS, check engine, almost everything came on, car lost power--> limp mode. Quick restart as I'm in the middle of the road, the warnings were still on, but the car worked fine, next startup, lights went out too.

Car worked fine for a couple of days again, then I got the same error again, this time right in the middle of the motorway. No matter how many times I restarted the car, engine was only capable of idling, so I limped back home on a nightmarish journey. Nearby shop connected VCDS, told me car dropped throttle body settings again, something about an angle sensor too, then I proceeded and cleaned the TB thoroughly, put it back together, didn't need to readapt, car worked better than ever, I could really feel it accelerate a bit better and fuel consumption got a bit better too.

This lasted for 5 days, this morning I got the same error on a super busy city road (nobody was happy). Then again, I managed to limp home, got another VCDS reading from the shop. Same codes, they retaught the TB again, this time it lasted for about 10 minutes (I was on my way to get a new TB as I knew this one was giving out, but the every shop was super busy and I need my A2 daily, so I wanted to change it myself ASAP). Long story short, my gramps gave me a lift, got the part, installed new TB, I knew I was gonna have to limp back to a shop, so they can install the adaptation or whatever on my new TB...Except they couldn't...

They tried to do the adaptation on 3 different VCDS', tried every setting, every channel. On channel 60 (not sure if I'm saying this right) they could connect to it, they started the adaptation, but it just wouldn't finish no matter how long we waited. Then we connected the old TB, now it couldn't read into that as well, but it could this morning...They gave up, told me to go back to the guys who installed CC, maybe they messed something up, maybe my ECU is fried.

Tomorrow my A2 is gonna get towed back to the CC guys, maybe they can pinpoint the problem, but if any of you have any ideas as to what might be the cause of this, I'd be happy to hear it.

(This is the TB I installed: https://cdn.bardiauto.hu/img/product/thumb/1/3/2/5/8/3/13258399_original.jpg
I know it's not the best, but it was the only one they had on the shelf and I wanted to get my car working ASAP)

Stay safe out there,
Mark

 

[Robin_Cox]

There are a bunch of specific criteria (I think they're referred to as "readiness" parameters) that all need to be correct for throttle body adaptation to be possible. Various combinations of lack of engine fault codes, coolant temperature within certain range and so on. If you've not met any of these then it simply won't happen.

See here :

Ross-Tech: VCDS Tour - Readiness

edit.

I've just re-read the above. To clarify my latter point, the last sentence should read :

"If you've not met all of these then it simply won't happen.". I can't remember whether 1 or 0 is the key value - but basically the readout should either be 00000000 or 11111111 ; any other combination means that something isn't right and adaptation will not happen.

 

[a-zwo]

It could be an ECU issue if it keeps losing the settings. What were the codes exactly?

 

[Meseburger]

It could be an ECU issue if it keeps losing the settings. What were the codes exactly?

I keep thinking that as well, I found this discussion: https://forums.ross-tech.com/index.php?threads/7584/

I did have the exact same O2 sensor error as mentioned in there, then I changed it, maybe it was too late or maybe the CC overwhelmed the already weathered ECU, who knows…

I don’t remember the exact codes related to the throttle body (didn’t want to disturb the guy too much by asking to take pictures of the codes as I could tell he was really angry the damn thing wouldn’t work, even more beat up about it than me lol).
All I know it was 3 codes, basic settings lost, something about the signal of the angle of the flap (it was an intermittent error), third one I can’t remember.

Later this day I will maybe know more. Car will be towed to CC guys, I just fear they will rip me off and I’m already all out…

 

[a-zwo]

I am 99% sure it’s nothing to do with cruise control. The ECU also has internal protection on its output do it shouldn’t damage itself with the O2 sensors either. However that can damage the catalyst.

If non of the faults were checksum errors or “EEPROM” errors, then I doubt the ECU is faulty too. It still could be, but it’s more likely to be loose or damaged wires between the throttle body and ECU

 

[Meseburger]

Found the culprit!

Several legs on my ECU were oxidised as hell (they literally turned all green) and those exact legs were responsible for throttle control.

Cleaned them up, took my car to a shop to adapt the TB one last time (it worked fine without adaptation as well, but CC only works with proper settings) and now all that’s left to do is pray they will take back the brand new throttle body I barely used, it was not cheap…