Hi, I have a 2005 R53 with 107,000 miles on it. I drove it through some snow the other day (unplowed Michigan roads) and started seeing some weird symptoms. First the Service Engine Light, the ABS light, the DSC light, and the Tire Pressure Warning light all came on at once. I checked my bluetooth OBDII sensor and it was throwing the code P101F which I read somewhere was the Ambient Air Temperature Sensor.

I've read that the DSC, ABS, and Tire lights usually mean something is wrong with a wheel speed sensor, but the other problems are making me think it may be something else. I noticed today that the outside air temperature according to the car is 122 degrees and it is the winter here. Also, my heater was oscillating between blowing very hot and very cold air this morning when set at 72, then it settled on cold air and I had to turn it to Hi in order to get the heat to turn on.

Is the outside ambient air temperature sensor used by the A/C or heating system?

Another note, the DSC, Tire Pressure, and ABS lights have turned off for now (that happened earlier as well, but they came back) but the Service Engine Light is still on and the temperature problems are still here.

Any ideas?

 

I think you have two things going on

As you mention the ABS, DSC and tire warning will all come from a wheels speed sensor issue. Possibly one got wet or a break in the wire insulation allowed water to short it out and then it dried or is is moving causing the warnings to come and go

Do you have automatic a/c ... sounds like you do. I can't swear to it in a MINI but my current daily driver has an automatic a/c system and a while back I managed to knock off the outside temp sensor and my system went a little nuts. In my case when I'd start the car the system would see the outside temp as 20 below zero and kick the heat on full blast. This would be good for you but at the time I was in south Florida .... in JULY! i thought my 'incident' had somehow impacted the a/c as the dealer swore the outside temp sensor had nothing to do with the issue. I wasn't so sure so held off messing with the a/c until I got the temp sensor fixed. Mine was in the pass' side mirror which had been broken off by a bird strike at 80 mph on I-95. When I got the new mirror - and enclosed temp sensor - my a/c went back to normal .....

The sensor lives behind the lower grill and is easy to replace ....
https://new.minimania.com/part/NMX86...n1-R50-R52-R53

there's a place where it clips onto the inside of the lower bumper cover

in my dd, the a/c would settle out after about 10 minutes when the inside temp sensor seemed to take over from what the system saw as the outside temp .... I never found a way to go to full manual control on the a/c in that car tho ..... everytime I started out the heat came on full blast. The mirror was torn off damaging the body where it attached to the tune of $470 ... damn bird was last seen disappearing under an 18 wheeler with my mirror! Dive bombed by a wood stork .... grrrrrr.

 

The sensor wires come from the Drive Side with the sensor being clipped onto the back of the bumper cover just to the right (as you are looking at the front of the car) of the lower grill.