Parasitic Draw ECU-B

Parked my 2017 Tacoma at the airport for 5 days. Came back and it had some trouble turning over but it did start.

Once I got home I checked the voltage coming off the battery and it was low. I hooked it up to a charger and let it do its thing, but ultimately the battery appears to have a bad cell when load tested.

Fast forward, I now have a new Odyssey battery installed. I figured I would check for a parasitic drain on the system just to be sure. Low and behold I have discovered a draw of about 250mA when the truck is completely off. I even waited a hour with the volt meter attached to allow for the computer and all sub systems to stop pulling power. I also ensured that my keys were a considerable distance from the truck as well during this testing.

I isolated all of my aftermarket accessories as I was convinced that something I installed was causing this issue. None of them had any affect on the amp draw. So I then started pulling fuses until I found one that reduced it down to 20mA or so. This fuse was a 10 Amp fuse labeled "ECU-B" Lots of information on the internet about it for other Toyotas, but none with a real resolution to the issue.

I expect there to be some draw on the battery, but I have always had older vehicles where 50mA seemed to be the norm. Does anyone know what the idle draw should be on a Gen 3?

UPDATE 1:

The dealer is struggling to identify if there is a problem or not. I am unsure of how I feel about that as it seems to be pretty straight forward. Truck has now been at the dealership for 48 hours.

Have been informed that they are escalating the issue up the chain.

 

UPDATE 1:

The dealer is struggling to identify if there is a problem or not. I am unsure of how I feel about that as it seems to be pretty straight forward. Truck has now been at the dealership for 48 hours.

Have been informed that they are escalating the issue up the chain.

 

Did you get this resolved at the dealer? I'm having the same issue with my 2017 Tacoma.

 

Original battery?, if so they don't last long. Mine went bad at 18 months. Many have had this happen. It was replaced by dealer.

 

I have a new battery. Truck at specialty shop now and fingers are pointing to ECU-B fuse. Which controls a bunch of stuff. Already unplugged aftermarket stuff - not those causing it. Trying to figure out what to do next. Dealerships are scary.

 

@caribe makaira

 

https://www.tacomaworld.com/threads/psa_fyi-ground-terminal-from-battery.628383/#post-21507358

 

Personally I’d check and double check aftermarket accessories. The remote tailgate drop/unlock along with a few others with similar designs are my first thoughts due to their nature of their design.
After that it’s see what’s on the suspect circuit from wiring diagrams. But since it’s at the dealer, not a lot you can do at the moment.

 

Hey man, I had a short in the main harness that was fixed by Toyota. Sorry that I did not post a followup.