2019 Subaru Outback - Parasitic Battery Drain - Dead every morning

Question

I'm on my third battery in two years for my 2019 Outback. If the car sits over the weekend, it's completely dead by Monday morning. The dealership says the battery tests fine and the alternator is charging at 14.2V, but something is clearly sucking the juice out of it at night.

I've made sure all the interior lights are off and I don't have anything plugged into the USB ports. I'm seeing a 450mA draw when the car is off and asleep, which is way too high. Anyone know which module stays awake on these?

FleetMech_Ed · Accepted Answer

✅ Confirmed fix: This is a known issue with the DCM (Data Communication Module) for the Starlink system. The module fails and constantly tries to search for a 3G signal that no longer exists, preventing the car's computer from entering sleep mode.

I pulled Fuse 9 (7.5A) in the engine bay as a test, and the draw disappeared. The final fix was having the dealer install a bypassed DCM or updating the firmware so it stops polling the network. There is actually a class-action settlement regarding this exact drain issue.

CumminsCowboy · Answer

Check the rear power liftgate module. Sometimes the 'open' sensor gets confused and keeps the CAN-bus awake all night trying to verify the latch position. Try pulling the fuse for the power hatch and see if the draw drops below 50mA.

2019 Subaru Outback - Parasitic Battery Drain - Dead every morning

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