X5 Engine And Trans Failure

[tomsawyer]

I just picked up a new 4.4i. On the second day of driving, with less than a 100 miles, something really strange happened. All of a sudden, all the dash board lights came on and a very strange noise came out of the speakers. It was almost as though I was picking up a CB radio transmission. At that point, the LED display said "Engine Fail Safe Mode". The "service engine soon", "4x4" and "abs brake" lights came on and the car was stuck in second or third gear and no matter what I did the car would not up or down shift.

I got home and when I turned off the car again engine fail safe mode come on and this time, "Trans Fail Safe Mode" came on.

The next day I drove the X5 to the dealer and everything seemed to reset. The car shifted normally and no lights were on except the "service engine soon" .

Does anybody have a clue what could have happened? Could a radio wave or some type of interference have done this?

Thanks -

[24valve]

Originally posted by tomsawyer@Feb 21 2005, 04:36 PM
I just picked up a new 4.4i. On the second day of driving, with less than a 100 miles, something really strange happened. All of a sudden, all the dash board lights came on and a very strange noise came out of the speakers. It was almost as though I was picking up a CB radio transmission. At that point, the LED display said "Engine Fail Safe Mode". The "service engine soon", "4x4" and "abs brake" lights came on and the car was stuck in second or third gear and no matter what I did the car would not up or down shift.

I got home and when I turned off the car again engine fail safe mode come on and this time, "Trans Fail Safe Mode" came on.

The next day I drove the X5 to the dealer and everything seemed to reset. The car shifted normally and no lights were on except the "service engine soon" .

Does anybody have a clue what could have happened? Could a radio wave or some type of interference have done this?

Thanks -

[snapback]296508[/snapback]

I'm no X5 expert but it sounds like your entire electrical system failed on you there.

[Dirty_Tool]

What happens often times is that sensors in the engine are related to the transmission as well. Some engine problems effect the transmission. the engine control module and the trans control module communicate over a bus called the can bus. Some sensors which send data to the engine module also send redundant data to the trans module over the can bus. This is why sometimes a simple sensor problem can make the dash light up like a christmas tree and really make you think that your car is falling apart. An example of this is the electronic throttle motor. A problem with this will effect the engine as well as the transmission. You did the right thing by taking the car to the dealer. they can interrogate both modules and find the problem for you. Hopefully you have warranty so there is no money out of pocket. Good luck and keep us posted on how it turns out.

DT

[tomsawyer]

Got the X5 back from the dealer and they told me they ran the diagnostic. Apparently, they were able to reset everything and nothing showed as a fail. The tech, who is also a friend, did indicate something about the can bus. However, at this point, they did not change anything.

Should they have changed the can bus?

[Dirty_Tool]

no no the can bus is just wiring . 2 way communication over wiring. You wouldnt replace the can bus. You would replace whatever the source was which was sending the message over the can bus from the engine module to the trans module. Make sense?
DT

[tomsawyer]

Just wanted everyone to know that nothing, in terms of failures, has happened since I opened the topic.

The best the dealer has come up with is that they would like to reprogram the dash. Not exactly sure what they mean by that.

Also, not sure if it's necessary now? What are your thoughts?

Thanks to all who reply.

[325isBaby]

You may need to have the vehicle reprogrammed and brought up to the next software level or you may experience this again...as a tech we try not to suggest un-necessary programming since some componants can only be programmed a limited number of times.