Hey guys, I am stumped by my car. (2000 1.8t ME7.5 512) Flashed my revised maf file, try to start the car and... does not fire! I check the codes, there are multiple codes related to the throttle body. They will not clear and I have no response from the pedal. Does not adapt, and does not start. I then took out the ecu, placed my stock ecu and get the same issue.
The TB is clean, wires are all giving proper voltages (5v @ pin 2-gnd and 5v @ pin 2-6), when logging measuringblock 62 I get 2 working graphs for the pedal sensor, and 2 inverse graphs for the TB angle sensors when I move it by hand. I took it apart, looks very clean inside. scrubbed the brushes a bit and did a test on a seperate power source (11v) and the throttle valve will open/close very fast and strong.
When I put it back in the car, I can hear it whizzing when I switch ignition on, but it does not open or close as usual (pre start adaption). If i press the accelerator I can hear it "click" but it is not strong enough to open.
What voltage is sent by the ecu to control the motor? Is it 12v or 5? I did a quick test with my DMM connected to the plug pin 3+5 (motor power supply) and I get a quick flash of 7.4v on the screen. Now this is not a quick or expensive multimeter so it might not be a really precise reading.
Could it be that the motor requires 12v but is only seeing 7-8v because of a wiring problem? Or do you guys have other experiences with this sort of error? I could buy another TB, but if the problem is in the wiring or ecu thats a waste of money and time. Especially since I have working angle sensors AND a verified working motor on 12v...
Please share your thoughts!

i has the same problem after washing engine bay
checked TB wires and connectors - all ok
problem dissapeared next morning

Nice! Good job tracking down the issue, stuff like that is often hard to find.