driver side mirror Ambient Air Temperature is -198.40 F

autoshiftin · Post by **autoshiftin** » 14 May 2020, 02:48

Has anyone experienced this before? My ambient air temperature sensor reading from the driver door side mirror is -198.40 F. Yes, that is pretty cold, and of course wacky. There are no codes at all, no check engine lights, not even one for "temperature out of range" which logically should be present. The other ambient air temp sensor in the passenger door side mirror is fine, and sends the temperature to the dash for the driver. I am wondering about this -198F since I believe this temp reading is supposedly sent to the ECM for engine and fuel management. So it would then seem that my car thinks it is driving in freezing Arctic temperatures Ugh.

Since the sensor is surely the original one from ~2004 year of manufacture, I went ahead and replaced the sensor with a new one, OEM Volvo. After installation of the new temp sensor, I was surprised to see the same temperature reading of -198.40 F on the scanner. Can anyone assist on any tips and direction to go on this? Thanks.

Post by **darrylrobert** » 15 May 2020, 00:02

my cars left mirror (ECM) reads 0c. right mirror (DIM) is correct at 25c.

Ive asked on here before and got no replies. I dont think anyone knows this mystery.

I have checked the sensor in the mirror and the values are within a correct range for reading 25c yet the car still reads 0c. Its eaither the wiring or ECM. I havent checked the wiring to the ECM because i am yet to find a wiring diagram for the sensor to ECM pins. I havent found out what this sensor does, i believe its a secondary (backup) sensor.