P2100 Throttle actuator control motor circuit open FAULT MIL LIGHT

[petrolhead63]

Hi, my 2.0tdi keeps putting MIL light on, but no driving faults obvious. Each time I reset it comes back intermittently..maybe a day maybe an hour of driving. What is interesting though is it has not yet come on whilst running, it is when I come to it turn ignition on and start it, the MIL light then does not extinguish.

Reset it again and it carries on driving fine and the light stays off until it decides to not extinguish on a start up.

The code indicates electrical fault in throttle valve or its circuit/supply but the car drives fine.

The valve/flap/motor cant be burnt out or the car would not work I assume, any body have any ideas?

I assume it could just be a momentary flutter of open circuit so I do not notice a fault in driving...it will no doubt let me down soon though if not rectified.

I wondered if it has something lazy like a relay when I turn the ignition on? but not sure where the power feed comes from for it, fuse, relay?

Thanks for any ideas.

[Crasher]

The throttle valve is only there for anti shudder shut down reduction and as part of the EGR strategy, a Diesel engine isn’t throttled as such, it is fuel delivery controlled.

[petrolhead63]

ah yes, was not thinking it through really. Though if the flap was not open would the car go badly due to very restricted air intake?

is the flap normally open or closed at rest? It could just be a failing/intermittent throttle valve then?