2020 Toyota 4Runner: Battery drained when not in use
Common wear/failure (not a recall)
Symptoms
Owners of the 2020 4Runner report: battery drained when not in use. CarComplaints.com lists 1 owner complaints, average mileage 2,100 miles.
NHTSA has 1 owner complaints for the 2020 4Runner in this area. Examples:
- NHTSA complaint ODI #11760224 (filed 08/28/2026): “The door actuator have been replaced a minimum of eight times. huge safety risk involved since we never know if the vehicle is going to lock. toyota continues to replace them but not addressing the underlying issue. not sure if this is all related but the blo…”
Likely causes
Sources do not establish a single root cause; diagnosis is needed. Owner-reported fixes are listed below.
Fix, in plain English
Most common owner-reported solutions on CarComplaints.com: none clearly reported. Check for open recalls and extended warranty coverage with a dealer before paying out of pocket.
DIY difficulty: Moderate
Finding and splicing chewed wiring is doable with a multimeter and patience but can be time-consuming; harness replacement is pro work. (Our assessment.)
Cost
CarComplaints.com owners report a typical repair cost of about $60 (owner-reported average, not a quote).
Typical parts (search links, no affiliate codes)
AutoZone · O'Reilly · Advance · RockAuto
Sources
Page last updated .