Santa Fe - A/C Digital readout - Outside temp way off

My wife has a 2007 Santa Fe. Recently the "outside temperature"
number is way off. When she turns on the vehicle it registers below
zero.... this is Florida, in the summer.
It will eventually read the correct temp after driving for a while.
What's causing this?

 

TSB 07-90-001 for inaccurate ambient temperature sensor
Covered by warranty.

 

TBS? Technical Service Bulletin? Hadn't heard of that.
The Santa Fe was bought used, and is off the limited warranty that it
came with. Does that mean we're out of luck? Or is a TSB like a
factory recall?

 

TSB is not a recall. l It just tells the service department how to do a
special fix.

I can't say for sure about yours, but way off readings do happen with the
sensors on many brands of cars. With one of my GM cars I went through a
carwash and then temperature reading dropped 25 degrees and stayed thee for
a week. On another, it just stopped working and was a two minute fix to
replace the sensor.

 

This is a known problem with the junction block under the hood of the
Santa Fes. Rather than pay to replace the junction block, Hyundai
came out with a "special" fix of running wiring to bypass the junction
block. If you've got more than 60k, it's no longer covered, but you
can register for a free account at www.hmaservice.com, read the TSB
and do the repair yourself. Or you can replace the junction block.