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.

AC is not working Inspection $111.46 - $131.46 Get a Quote

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How Long Should Headlight Fuses Last?
All fuses in your vehicle are technically designed under normal conditions to last the life of the vehicle. A fuses primary job is to open up if the current flowing through the circuit it is protecting exceeds its rated capacity....
Car stalling and dying
Hey there. All of the problems you indicated should most certainly set a Check Engine Light code. Oftentimes, a vehicle may not have set a Check Engine Light but could still contain a code in the computer's memory. Hook the...
Muffler hanging from bottom of vehicle.
I recommend having a qualified mechanic, like one from YourMechanic, replace your severed exhaust pipe (https://www.yourmechanic.com/services/exhaust-pipe-tube-replacement). The exhaust may have also damaged the manifolds of the engine and caused wiring damage to the exhaust sensors. The exhaust systems on these...
Difficult startup, chugging and rough revving
Hello. If the engine is having trouble starting after it has ran for a while and you are getting the smell of fuel, then it may be a failing fuel injector (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-fuel-injector) or an issue with a bad sensor. Most...
Car stalls, rpms go up, & no power
Hello. This can be caused by a number of things. I usually start by scanning the computer for codes. This will give me an indication of anything the computer is seeing. If it is not seeing anything, then it may...
Fuel pump just clicks once not running
The fuel pump is going to be the most common cause of the loss of fuel pressure. I recommend having the fuel pump replaced. The fuel system and pressures should be completely checked prior to replacing the pump. I recommend...
Driving from Washington to Oregon when I got home battery boiled over. The 4 wheel drive dash lights and overdrive are on.
Hello. With so many lights indicating on the dashboard such as the check engine light and the overdrive light they will certainly be codes present inside of the transmission control module and engine control module. I suggest that a technician...
Do I need to replace the whole rack and Pinnon if I found the leak
If you found the leak and the rack and pinion is leaking then you will need to replace it due to most repairs require specialized tools and training to rebuild or repair steering rack and pinions. If it pressure hose...
#7 misfire on my 2002 Dodge Ram 1500 4.7 replaced with new spark plugs nd replaced coil still getting error
Check compression in that cylinder to rule out a mechanical issue such as stuck valves or very low compression. Another possibility is a vacuum leak around the intake to that one cylinder. If so, that can cause a misfire. If...

Related articles

P0328 OBD-II Trouble Code: Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)
P0328 code definition P0328 is a general OBD2 diagnostic trouble code pointing to a fault within the knock sensor 1 circuit. What...
P2647 OBD-II Trouble Code: System Too Rich (Bank 1)
P2647 P2647 code definition A Rocker Arm Actuator System Stuck on Bank 1 What the P2647 code means This trouble code indicates that the powertrain control module has detected a malfunction in the intake camshaft rocker arm actuator system (A)....
P3484 OBD-II Trouble Code: Cylinder 11 Deactivation/Intake Valve Control Circuit High
P3484 code means cylinder 11 was deactivated during certain driving conditions due to low oil pressure, engine condition, or electrical components.