2011 is250 idle issue. Throttle body was replaced and now scanner is reading throttle position at 51%. I read that it should be somewhere around 14. Is there a way to adjust this or does a trip to the dealer the only option.

 

What caused the TB to fail? This is the first of I heard of one failing.

 

51%, how high is the idle, like 4k??

It must have some codes. Please report what they are! As noted above, it must be something else.

 

Had a high idle on my 08 IS 250 along with some shaking but after changing the spark plugs it was gone. Don’t know if that helps in any way?

 

I had a high idle two nights ago - 2300 to 2600 for three or four minutes. It was very cold but I didn't expect it. This afternoon I started her up after replacing the steering and she went up to 1500 but then it fell back to 1100 pretty fast. This was with the local temp 51F. I still don't know why the previous start was so high an rpm idle. No codes when I checked it.

 

Have you tried disconnecting the battery, waiting a couple of minutes, and plugging it back in? That resets the ECUs and may recalibrate the throttle sensor.