2019 Ram Bighorn Parasitic draw- BCM?

[aabel16]

Hey all!

Love this forum. I searched around for this specific topic, but couldn't find anything that matched my situation.

My truck sat for close to a week in my garage.. battery is 1 year old. Completely dead. Never had issues before. Charged the battery and it started fine. Brought the battery to auto zone to test and it passed.

I went on, and found parasitic draw. .80-.90 amps after all the computers calmed down. Went fuse by fuse... the fuses to the BCM are the issue. Without them, draw is only .3-.4.

Had anyone had their BCM go bad like this? Luckily, I'm able to get a replacement for a fairly cheap price from a junkyard, and know ill need to reprogram the unit via AlphaOBD, but I'm just curious if anyone has saw this? I'm leaving my truck at the airport for 5 days starting Wedneaday... not enough time to make sure it's the fix so I'll probably just disconnect the battery when I park it.

 

[suli]

Nice troubleshooting. Did you also try a BCM restart with a tool? You may also want to just remove the + battery terminal, press the brake to make sure the system is drained, and wait a bit and plug it back up to reset all the systems. I haven't heard anything about a bad BCM drawing power. Is it a BCM controlled accessory possibly (like radio/uconnect, telematics, etc) that might be the culprit?

I assume you are out of warranty? May want to unplug it or toss a jump pack in the truck if you have one for your return.

I just replaced my 19's BCM with a 23+ BCM (68584071AG) for the Aux switches. Needed to have it programed to match the VIN/Truck by a dealer (more than Alfa/Jscan work I think, but someone can correct me please).

 

[vincentw56]

Nice troubleshooting. Did you also try a BCM restart with a tool? You may also want to just remove the + battery terminal, press the brake to make sure the system is drained, and wait a bit and plug it back up to reset all the systems. I haven't heard anything about a bad BCM drawing power. Is it a BCM controlled accessory possibly (like radio/uconnect, telematics, etc) that might be the culprit?

I assume you are out of warranty? May want to unplug it or toss a jump pack in the truck if you have one for your return.

I just replaced my 19's BCM with a 23+ BCM (68584071AG) for the Aux switches. Needed to have it programed to match the VIN/Truck by a dealer (more than Alfa/Jscan work I think, but someone can correct me please).

Exactly, you will need to have the dealer program it and I don't think you can use a used one. Not sure on that one. But if I was replacing it, I'd use a newer one from a 23+ like you did.

There will always be a parasitic draw. It shouldn't be enough to kill a good battery.

 

[aabel16]

Thanks guys. I think I was chasing the wrong issue. My "fancy" multimeter times out after 10 min to save the battery, so I could only hook it up in series for up to 10 min. I dropped some money on a amp clamp today. After hooking up the battery and waiting 20 min the amp clamp showed less than 50 ma. I'm still stumped though how my battery was completely drained. I'll give it a shot this week at the airport. If it's dead again I'm going to be an unhappy person and demanding a replacement on this 1 year old everstart battery that tested good.

The junkyard hasn't told me the bcm I ordered is ready, and it was only $40 so luckily I'm not out much if i cant cancel the order. Kinda silly they can't be reprogrammed.