2020 GMC Sierra 2500HD: Battery has died several times
Common wear/failure (not a recall)
Symptoms
Owners of the 2020 Sierra 2500HD report: battery has died several times. CarComplaints.com lists 1 owner complaints, average mileage 14,000 miles.
NHTSA has 13 owner complaints for the 2020 Sierra 2500HD in this area. Examples:
- NHTSA complaint ODI #11762323 (filed 09/05/2026): “When i try to start my truck it comes up as service trailer brake control module and it has caused my truck battery to drain so i cant even crank my truck up.…”
- NHTSA complaint ODI #11706292 (filed 12/20/2025): “The main tailgate will not go down or function properly and it says online there is a national recall for this, but does not come up when i search my vehicle. when i turn on my left turn signal the brights flash for no reason and this is a known major issue w…”
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: the seat memory control module can kill the battery (1 reports). 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
No sourced cost range: get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
AutoZone · O'Reilly · Advance · RockAuto