1991 BMW 525 computer problems

1991 BMW 525
20,300 MILES • 6 CYL • 2WD • AUTOMATIC
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FLYBOY97222
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The onboard computer that tells me MPG, Time Date and all the other cool stuff I like to track on my car, has gone dark, I can see the numbers if durring the day but the back light has gone out, but also when I use the dash to pull up the info I only get Time, outside temp, Average MPH, Distance to Empty, and that is all.
Nov 18, 2008 at 11:03 PM
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DOCHAGERTY
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The OBC is back lighted with 1.5 watt bulbs that can be replaced. Remove the radio and there is a lever in there to release the OBC. It takes a very small screwdriver and small Allen wrench to remove the radio.
Nov 19, 2008 at 11:17 AM
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FLYBOY97222
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Thank you very much. But that doesn't answer why I only get partial data on the dash computer now.
Nov 19, 2008 at 11:31 AM
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DOCHAGERTY
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To restore full operation of the dash display removing the OBC and replacing the bulbs should reset the functionality of the OBC. It is like control/alt/delete on your computer. If that does not work you may need to disconnect the battery for several minutes to achieve the desired results. Keep in touch.
Nov 19, 2008 at 12:21 PM
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FLYBOY97222
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Thank you- I will try both. and keep you informed.
Nov 19, 2008 at 12:22 PM
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DOCHAGERTY
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Let me know if you need a radio code.
Nov 19, 2008 at 1:56 PM
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FLYBOY97222
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Okay- got the OBC out and looks like I need to get the bulbs from BMW? also I tried unhooking my battery and also just unplugging the OBC but the dash is still giving me partial info. I'm going to try and unhook the battery while I have the computer out.

It never asked for a code? weird.
Nov 19, 2008 at 2:07 PM
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FLYBOY97222
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I had to order the Bulbs online from Pelican- $.75ea and $7.50 to ship.

I also might think it the other problem might be the OBC control unit. do you know where that is located?
Nov 19, 2008 at 3:20 PM
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DOCHAGERTY
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The on board computer is pretty much self contained, there may be something that I just dont remember about the info display, I will try to have a discussion with a contact of mine and see what I can find out ASAP.
Nov 19, 2008 at 3:49 PM