Exterior temp reading

[daddyo8]

My e39 reads -40 degrees for exterior temp at all times, and although I replaced the sensor, under the passenger front wheel-well, it persists in this unacceptable behavior. Is there a reset button for this feature. I have consulted my Bentley's book but it doesn't go into this type of detail needed.
Any input?

[daddyo8]

I can get the weather report on my phone. However I have heard that the exterior temp reading somehow has a bearing on the AC/Heat system causing the interior temp not to act properly.
Is this a valid concern? Anyone out there have some more info on this matter?

[Cassidy Dannie]

The temp sensor is located in the middle of the grille and with a winter front on no ambient air gets to the sensor so heat from the radiator gives you a false reading. The sensor should be relocated on the rad support close to the drivers side headlight

[BAVARIANM]

Wrong. The temp sensor mounts in the lower inner wheel well extension. The sensor is either faulty, or the wiring harness/sensor has impact damage. The dealer has a replacement harness if needed