my obc has gone!

[bobchiba]

several weeks ago i noticed my obc would sometimes revert back to time/date as i usually leave it on temp. Also once or twice it didn't turn on when i started the car, however it sorted itself out the next time I used the car.

Then one night I used the code function to immobilised it and deadlocked the car. That night the alarm went off and again twice the following morning. I live in a very built up area so to avoid being that guy whose alarm goes off every night I disconnected the battery, aware that next time I used it I would do the 15min count down thing, but that wasn't a problem.

Then a few days later I reconnected the battery, turned the key and nothing, no countdown because the obc is now properly dead!

I presume the obc dying and the false alarms are related, but Im under the impression this maybe a fuse or relay problem from what ive researched?? The rest of the car/electrics are all still fine.

does anyone have a photo of the fuse box and the relavent fuses? and if someone also has a pic of the dwa module that would be great.

Really appreciate any advice you guys can give me/similar probs etc.

[Rus]

One of the first things to check on these cars when you experience random electrical trouble are the fusible links underneath the rear seat. They can crack and you'll have intermittent power delivery. A quick search for "fusible link" on this forum will likely even yield pictures of the buggers. HTH

[BMWDriver]

If memory serves me right, there's a fuse on the OBC. I could be mixing this up with the radio which has one on the back of it. You also ought to check the fuses, engine bay and under the rear seat.

[bobchiba]

ok thank you, is there anything else on the same fuses(?) that might be affected, my windows and sunroof work, but haven't tested anything else...

[BMWDriver]

Usually, fuses handle many items. You'll see them listed on the fuse box. I would also suggest checking the connections to the OBC, and also the connections to the instrument cluster, because the OBC feeds alot from the cluster to analyse the data and pitch back the info on its display. It also displays its information on the cluster as you choose.

Basically you press your turn signal inwards to display various info from the OBC. To set it up, you press the turn signal lever inwards at least two seconds, and then press the info on the OBC that you want displayed in the cluster.

This may serve to determine if your OBC is truly dead. If you get info displayed, then its light bulbs are out.

Checking that the connections are secure means pulling out the cluster and the OBC. Lots of info on bmwe34.net with pics. I would almost put my money on the cabling because your display was reset and worked.