After Jumpstart, Onboard CPU & Gauges Dead
 

Over the weekend, I parked my 2005 BMW X5 overnight, and when I returned to the car, the battery was dead. I didn't leave the lights on, and I'm not exactly sure why the battery was dead.

After a jump start, the car seemed to be alright (it ran fine, and could be restarted). Except the on-board computer would not work, the gas gauge would not work, and the RPM gauge would not work. The only gauges that do work are the speedometer and the water temp. The on-board computer (display that shows the MPG/timer/distance to empty, etc.) is totally blank, and won't come back on, regardless of what buttons I press.

I haven't tried much besides searching the forums, and I didn't find anything exactly like this. One post suggested disconnecting the battery for 15 minutes (similar problem) but I wanted to reach out to the community first.

Should I just take the car to the dealer? Should I try the battery disconnect method? Other thoughts?

Thanks!

it might be in safe mode...did the transmission seem like it was stuck in one gear?

I'm not sure about safe mode, but the transmission seems to be fine, drove it on the highway for 100+ miles and then did some city driving.

At this point, it seems like the best bet is just to take it in. :tantrum:

When the voltage goes low, the electronics can do some weird things. I agree taht doing a battery disconnect may be all it needs (fingers crossed) as it will do a full power reset on all the modules and may get them all working properly again. If that doesn't work then bring it in. (thinking you likely checked fuses already)

I lost my central locking (remote, etc) after a jumpstart. Fortunately it was under CPO warranty took in and they fixed.

The Relay was fried I guess after the jump.

-bdf

Thanks. Mine is CPO, so I hope it's covered as well. I'm taking it to the dealer tomorrow, so I'll let you know what this turns out to be.

BTW, I just took it in and said it stopped working. I didn't elaborate and they didn't ask...

Bump... What did the dealer say? Mine has recently suffered this same problem after my brother borrowed it and left the lights on. After he jump started it, the outside temp is stuck, and the LED display has some of the pixels lit all the time.

almost the same thing happened to me. I left the stereo on while cleaning/detailing the car and totally forgot about it until and hour later. I had road assistant jump started the car and many weird things happened. At first, the car was fine but a day after I have Check Engine light and the transmission acted strangely. I brought the car back to the dealer; it turn out that the jump start fried my alternator and battery and throw the transmission in safe mode. I never realize that jump starting the car could cause such issues. I guess that I won't be having the radio on the next time I detail the car. Thank god for warranty.

It was suggested to me that with all the modern electronics on any newer BMW avoid jump starting if possible (use of a trickle charger, for instance). It was presented that there could be a surge when the jumper cables are removed and strange electronic problems have been noted even after a week or two of a jump start.