Q: outside temperature thermometer way off, a/c not working, check engine light is on

asked by on September 06, 2016

hi there, my girlfriend has a 2015 bmw 328. she was out of town on a long weekend, and when she got back and picked up her car, which was parked in her sister's neighborhood, there were a few things acting strange:

  1. her thermometer is telling her the outside temperature is -40 F when it was actually 80 F
  2. her air conditioning isn't working
  3. her check engine light is on.

she thinks someone may have messed with her car while she was gone (she read something online that this can occur when wires are snipped)...any idea what may be causing these issues?

Thanks so much! Pat

My car has 15000 miles.
My car has an automatic transmission.

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Hello. The reading of minus 40 degrees does indicate that there is an open circuit in the sensor circuit. This will cause the A/C not to work and the Check Engine Light to come on. The sensor is in the front under the front bumper bottom cover. Look for damage underneath from hitting curb stops and you may be able to find the problem. If no damage is found, then have the sensor checked to see if rodents have chewed the wires or the sensor is damaged. If you need help having the problem scoped out, a certified technician from YourMechanic, can come to your car’s location to inspect the entire A/C system in order to have this addressed.

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