Why is ambiant temp atuck at -40 - 2006 BMW 330i

Yes but you can also use your phone camera by facing your phone as if you want to take a shot

Up in front of the radiator--it you're talking about the sensor for the cabin display. If you're talking about the intake air temp sensor for the engine computer, it's built into the MAF sensor

These sensors are not supposed to be super accurate so, a couple of degrees out is prob reasonable.
You may have a higher resistance in that circuit which could give different readings so check and clean all connectors and plug fittings.
Roger

ambiant air temp sensor is probaly broken or disconected it should be in the front bumper small black plastic with 2 wiers looks like a pencil tip

TEMP SENSOR IS LOCATED BEHIND FRONT BUMPER COVER CLOSE TO AC CONDENSOR. CABIN FILTER SHOULD BE UNDER COWL PANEL ON PASSENGER SIDE

Throttle body in front of throttle linkages/cables. IAT- Intake air temperature sensor.

Hi Chuck,here's a link on your coolant temperature sensor,and here's how to replace.here's how to test.Here's the part.

could be the coolant temp sensor for computer it still may be within its peramiters so it wont turn check engine light on. what i would do is wait till another really cold morning hook up the scanner to your truck if you can get access to one take ambiant temp and campair it to the sensor they should be spot on for temp. and resistance values, good luck

if it is carburated you need to adjust the fast idel and the choke if it is fuel injected try checking the temp on the coolant temp sensor with a scanner the temp might be reading wrong if it is differant than ambiant temp in the morning change sensor

Check the manual, you have to hold down Ambiant and the Temp Up button for 5 secs or something.