I'm looking at a 2009 XF luxury with the 4.2 at an auction. It has about 80,000 miles. I put a code reader on it and it has two fault codes 1) P0850 and 2) U101B

An internet search found these two together with a faulty/corroded wire found an 04 Stype with a corroded wire Here: Gearbox fault

Other than that it looks like the P0850 is Park/Neutral Switch Input Circuit fault.

I can't figure oyut what the U101b fault is, so any help with that is appreciated.

One other issue on this is that the center speaker grille is gone, and although I didn't look closely, it appears there is no speaker. I have no idea if this relates to anything else or is just a missing speaker and grille.

I used to have an Stype, but sold it with 221,000 on the clock a few months back. I'd love to rejoin the family.

Any suggestions on what the fix for this is?

 

Cant find the U101b. But maybe related to U0101 = Lost communication with TCM.

 

I've had U101A in the past, = "Lost communication with transmission control module".
That was under the Gear shift module set of code readings, so I suspect that U101B would be very similar. I'll check my reader and see if it gives a meaning for U101B.
Update - my code reader did not show U101B as being in it's database. But then it didn't show U101A as being in the database either, and I've definitely had a U101A code in the past. Weird.

 

Found this:
U101B OBD Code Definition:
Lost Communication With GSM – Multiple Bus

 

Might it be years old if no-one's cleared it?

Clear it, drive car, see if it comes back. If you can't, decide whether to gamble.

 

U codes are communications codes and are almost always in there for one thing or another. And unless Im dealing with a module, network down I ignore them and clear because they pop up randomly just like your PC/Phone loosing signal. You should try using a Jaguar laptop and see all the random codes that are in there for all kinds of random stuff that at not problems

 

thanks guys! it went for a little more than I was willing to pay with the issues it had. I'll keep looking, as I may have caught the XF bug...

 

5 years later. Did you find the problem? Also have that u101b code :-(