Expert: Roland Finston - 7/11/2011

Question
I have a 2008 Chrysler Sebring Sedan 2.4 liter.  I have noticed that the outside temperature reading on the instrument cluster is reading at 77 degrees and not changing.  I had the tires, brakes and oil changed almost two weeks ago, don't know if the problem dates back to that.  I just noticed that this was stuck @ 77 a couple of days ago.  The temperature here in central Illinois has been 90 plus degrees the past few days.  Nothing else seems to be wrong with the car, the air conditioning is also working just fine.  Is there anything I can check to get this working again?  Thanks for your help!

Answer
Hi Diane,
The ambient air temperature sensor is a small device that is mounted on the top edge of the front bumber support crossmember, accessible by sliding under the front and looking up from underneath at the that metal crossmember. There is a cable that runs across from the right side to the midline of the body and the sensor will be found at the end of the cable. It may be that the sensor is unplugged from the cable or it could be faulty or the wires that connect it to the engine controller maybe be damaged along the way. To check the wires: the violet/light green wire is connected to pin 32 of the C3 plug (black/orange color) plug at the engine controller module, while the black/light blue is connected to pin 27 of the C2 plug (black/natural color).
So that gives you what you need to know to find it, check the plug, and check the wiring if necessary. Once the signal reaches the engine controller it is digitized and used by the AC control unit and the readout which you observe to be stuck at 77. It is doubtful that the issue is at the readout if other signals at the that device are normal.
Roland
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