hey guys.

ive been having this issue recently with my battery draining constantly and ive been trying to pinpoint exactly whats going on. i dont know if ive missed this before or not but ive noticed that when i take my keys out of the ignition everything in my car still works until i open the door. sunroof, radio, all my gauges are still lit, windows roll down, EVERYTHING. everything works and the key is in my hand. now i thought everything was supposed to shut off when the key is out? especially my gauges that are on acc switches. but thats not the case here.

anyone have this happen or is it normal? if normal, how can i prevent it from happening? thanks alot.

 

 

so i did a parasitic draw test and after checking all my fuses i got a final draw of 0.05 amps. i removed the BCM2 fuse from under the hood and the RDO fuse from the interior panel to get it down that low.

does that seem right? if i plug the RDO fuse back in it comes up a good amount but i dont remember the exact number.

whats an acceptable draw on an lnf?

 

50mA is pretty small and should be fine. I don't know how the e69 works in this regard, but most modern ecus run about 100 mA when you shut down until it goes to "sleep" and the draw is minimal.

What is your battery voltage when the car is running?

 

sometimes its 13.8 and other times 14.0. i dont think its an alternator issue really but i wont rule it out either. the car runs with the negative battery cable disconnected.

i think what im going to do is let it sit overnight and see what happens tomorrow morning with these fuses pulled. last i checked my battery was at 12.57 so it should be good. ill check it again later on tonight to see if it drained.

also, i noticed my needles in the cluster move around after turning the car off so im gonna guess with that and the whole bcm fuse stopping my drain i have a bcm issue.

 

God Bless! Would you guys quit doing that!!!
Read up on how destructive that can be. It was barely save to do back in the 60's

 

Battery is probably just bad.

 

thank you! i dont know who ever thought this was a good idea as a means of diagnosing a charging system.

 

will a bad alternator drain the battery while it sits but still charge it while it runs? im getting a good 14.2-14.4 while the car is running but this morning the car was dead again even though i had the 2 fuses i know were draining my battery pulled. battery is new, just replaced a new one with another new one.

how about a bad ground? i have my prosport boost gauge grounded to a screw in the a pillar and power to an acc fuse in the interior panel. thats the only aftermarket wiring ive done and ive tested the same with and without the power connected.

 

stupid question but will replacing my bcm mess with my tune at all? i know it has nothing to do with the ecu but if i have the dealer install a new bcm i dont know what kinda stuff theyre gonna need to do to reprogram the new unit and whatnot.

 

You should probably just buy and throw parts at it. Eventually you'll get it right.

A shop doesn't want to hear "replace my BCM" let them diagnose it.

 

i think that with my doors locking and unlocking on their own, stuff staying on forever after i take the key out, my cluster needles shaking once i do open the door, my serious battery draw that goes away when i pull the bcm fuse AND error code U0073 its safe to say i have an issue with my bcm and i dont need further diagnosis.

i just want to make sure that once the dealer installs a new one and program it they dont mess around with my ecu as well and erase/reset stuff in the process. i have no idea whats involved in installing a new bcm so thats why i figured id ask here to see if someone has had it done.

 

The needles moving with the car off is normal.

 

So you're 100% sure of the problem but don't know what's involved in changing it?

Makes sense.