My digital exterior temp reads -40 degrees in May when it's toasty warm outside. Anyone have this problem in the past? How did you fix it?

Check the sensor, it might have been disconnected or fallen off. I believe it's on the driver's side in front of the front tire under the plastic panel.

E39 ambient temp. sensor is on the front pass. side in front of the splash panel.

installed new ambient temp sensor and still reads -40 degrees. what next?

installed new ambient temp sensor and still reads -40 degrees. what next?

Don't know if you've fixed this yet, but disconnect the battery for 10-15min, should reset it.