Skip the auto shop - Our mechanics make house calls

Q: Engine malfunction light, reduced engine power, engine powered down

asked by on

I was driving around 55 mph and the engine malfunction light came on, plus the warning message engine malfunction reduced engine power displayed. After this, the engine powered down. I was able to maneuver the car off the freeway and get it to my house. This problem has been recurring many times. This last time the car had to be towed to my mechanic’s shop. He was not able to duplicate the failure, so he wasn’t able to diagnose it. Would you please give me your assessment of this problem and what needs to be done to repair it?

A: Hi there. There are a lot of things that ca...

Hi there. There are a lot of things that can cause this on your 2012 BMW M5. I usually start by scanning the computer for codes to see what comes up. If there are not codes then I load test the alternator and the battery to see if they are failing. Low voltage in the electrical system will cause this. If that is fine, then it is usually caused by a failing throttle body. I have seen a lot of these fail due to the motors in them hanging up. If the problem is only happening intermittently, this can make the issue hard to duplicate, but you can still have tests done on the car. If you are going to have this fixed, consider YourMechanic, as a certified mechanic can come to your home or office to test the vehicle and diagnose the Engine Malfunction Light.

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

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: How do you operate the continuously variable transmission?

If your car is equipped with an automatic transmission rather than a stick shift, you actually have what’s called a continuously variable transmission, or CVT. These are a little different from conventional automatics. Here’s what drivers need to know: ...

Q: Reduced power mode

The reduced power mode is usually related to a Check Engine or ABS light coming on. When a problem is detected, the engine goes into reduced power mode to try and allow you to get to a safe stopping point....

Q: On right turn, car's engine shut down without warning

Hi there. There are some common issues with this vehicle that will cause this. Most of the time, if it occurs only when turning, it is because of a bad connection at the battery or at one of the control...

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...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...