Outside temp display in dash/PCM inaccurate

[steve_wilwerding]

I've noticed than when I first start the car in the mornings, the temp gauge usually reads between 15-20 high (it is stored overnight in a detached garage). I find that as I drive, it drops and gets close to the outside temp, but it takes quite awhile.

Any ideas? Is this normal? Does it need a new sensor?

[odix]

Hi Steve -- what you describe is normal. I see it on my Cayenne ('04 S) and in a relative's ('04 Turbo).

The most recent temp when you kill the ignition is stored and also the vehicle is well insulated and has a lot of heat storage -- be it the vast oil amount or metal in the engine compartment.

I noticed in cold (sub-zero) weather, parked outside, the issue is not present for long -- the temp display reflects reality quickly.

[clarksongli]

same here....i can only assume the ambient sensor is somewhere behind one of the grills.....when you shut the car down, it becomes heat soaked....but once you start it and drive forward, the air being direction into the front grills cool the sensors back down closer to real ambient.....but like Odix said, it always reads slightly higher than ambient and takes longer to return to normal when it's hot outside.