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Cardoctor71
Cardoctor71, ASE Certified Technician
Category: BMW
Satisfied Customers: 672
Experience:  ASE Master Certified Technician
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I have a 2001 540i msport. i was replacing an ignition coil

Customer Question

I have a 2001 540i msport. i was replacing an ignition coil and the ground wire sparked a second and I immediately got a rough idle. when I shut the car down and tried to restart it was in "engine failsafe" mode. It cranks but does not start and my obd will not communicate. Hoping there is a fuse or the car went into auto theft. struggling with this. thank you for your time.
Submitted: 6 months ago.
Category: BMW
Expert:  Cardoctor71 replied 6 months ago.

In order to help you, I will need more detailed information, it appears you were attempting to replace an ignition coil while the engine is running, which does not make mechanical sense.,

Customer: replied 6 months ago.
I was testing the coils to see which caused a rough idle when pulled slightly off the plug.
Expert:  Cardoctor71 replied 6 months ago.

The vehicle computer, interpreted your actions, as an attempt to steal the car, or tampering, which most likely has triggered the antitheft system. Try locking and unlocking the door repeatedly using the fob. Then attempt to start the engine. If this fails, manually lock and unlock the passenger door, with the key, then attempt to start the engine. If this fails, the vehicle computer will have to be re-flashed at a BMW dealer. Please rate my service, I will continue to answer your questions, until you are completely satisfied with my answers.

Customer: replied 6 months ago.
I tried the key multiple times. Since there was a spark could I have blown a fuse or relay of any kind? And strangely the temp needle goes all the way to red when key is turned on. Just asking as a last option before it has to go to the dealer.
Expert:  Cardoctor71 replied 6 months ago.

Spark is normal, when coil is removed from the plug, with engine running, its possible the coil spark, which incidentally is the improper way to check for misfire on a BMW, spiked the engine computer coil driver for that coil. Please rate my service, I will continue to answer your questions, until you are completely satisfied with my answers. Next time check for misfire on your Bemer with a scanner.

Customer: replied 6 months ago.
Sorry for asking but what would the result be If it "spiked the engine computer coil driver"? I'm not sure exactly what that is, is that the coil or possible computer damage? In my initial contact I was concerned that the -ground wire- sparking had caused this shut down. I am aware that isn't the ideal way to check for a bad coil. I could use a bit of help here and you seem to be more interested in teaching me a lesson than a solution. I've obviously paid a price for the mistake I made already. Thank you for your time.
Expert:  Cardoctor71 replied 6 months ago.

I am sorry I came across that way, The computer may be damaged, the coil driver is part of the circuit board of the computer, it would be highly unlikely that this has occurred I am inclined to believe some other issue has occurred simultaneously with the coil testing involving the anti theft system.

Customer: replied 6 months ago.
I do sincerely ***** ***** explanation and your help. Have a good day. I've yet to resolve it but I guess I'll let it go to the dealer for a cure and hope it's simple. :)
Expert:  Cardoctor71 replied 6 months ago.

Please rate my service on the ratings page,Thank You

Expert:  Cardoctor71 replied 6 months ago.

Please RATE my service on the rating page, No need to reply, unless you have additional questions, Thank you for using Just Answer.com