Skip the auto shop - Our mechanics make house calls

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

asked by on

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.

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. outside temperature thermometer way off, a/c not working, check engine light is on

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Searching for a short, I found something I don't quite understand 2001 Chrysler 300M

Hi there. If the vehicles electrical system has been altered with the addition of an aftermarket radio or anything else has been changed then it is hard to diagnose. I would need to see the colors of the wires to...

Q: No crank

You didn't mention why you replaced the harness or whether the starter was operating before the work. But since you have also replaced the battery starter and alternator, I'm guessing that you have been trying to solve a cranking problem....

Q: I would like to know what parts I need to replace VVT ECCENTRIC SHAFT SENSOR and Valve cover

Although we would need to confirm using your VIN number, the required valve cover in your application appears to be part #: BMW-11127552281. The required BMW Eccentric Shaft Sensor (Valvetronic) is part #: VDO-S119565001Z. These OEM parts can be installed...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.