Maybe leave fuse 74 out for a couple of days and see if your parasitic drain continues. This is one of the more common drain problems on the X5 and no guarantee is is your problem but the faulty TCU has been a problem for many including me. Doesn't cost you anything to try...

Interetesting project for sure. I've been reading and watching videos on this subject off and on all day.


Tested engine off voltage tonight; it's at 12.46v. Car has been sitting 11 hours.


I'm gonna run amp draw tests tomorrow; set up equipment, and if more than .4ma draw is revealed, I'm gonna start pulling fuses; one by one until the culprit is revealed.


Fun.

Where you getting this .4 ma number from ? :popcorn:

I think to nominal draw is 40mA (0.04A)...

I seen .05 amp used as a baseline in a YouTube video, and .04 used several times as a baseline in past threads here in this forum. What I've learned in the last 48 hours is the amp draw to kill an otherwise healthy battery (in 24 hours), should be quite significant on the multimeter; something like 3.0+ amps.



Working inside an x5 without triggering lamps and the other (driver present) features will be trial and error....and waiting 16 minutes each time ��

As QS says this has been beat to death. Our 2001 turns out the LED and sleeps soundly most nights. Others keep the little light on (Night light perhaps?) and also sleep soundly. If I remember correctly the 10+ years ago this was discussed the
lite/not lite was even in the same model year and also shared the same level of cluster.
So if your light does not go out and you have no problem starting then don't worry. Only pursue this "bug" if you have a problem as it has driven others NUTS!

:iagree:

You pulled fuse 74 and could start the next morning and were showing 12.4v which is as expected. Most likely you found your problem. Forget the light on the shifter. If you don't use blue tooth, leave the fuse out and all is good. That's what I did.

No problems today; car sat 48hrs and cranked right up when the Mrs went to the store.


No time to test amp draw yet, will do tomorrow.


The help in this community is awesome.


Salute

Don't bother testing. You've already found the problem. If the car sat for 48 hours and the battery didn't drain with fuse 74 pulled, then it was the TCU. Plug the fuse back in and see. If it drains you have a bad TCU, if it doesn't you could have had what I did, which is the TCU acting up after an alternator failure. It happened both times I had an alternator die. Unplugged it, and plugged it back in and it was fine. I got rid of the TCU though because I never used it and I didn't want to take the risk of it acting up again at an inopportune time.

Leave the door / tailgate open and wait until the car enters sleep. Take a DMM and measure voltage then amps across fuse 74. If you get close to 12v it's asking for current. Measure the current and if more than a few mA it's pulling current when it shouldn't be.


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