2021 Chevrolet Silverado 2500HD: Electrical System complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 17 owner complaints for the 2021 Chevrolet Silverado 2500HD that list the electrical system component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11704659 (filed 12/12/2025): “The contact owns a 2021 chevrolet silverado 2500. the contact stated that the connector for the heater system was causing the vehicle to overheat, subsequently enabling the vehicle to go faster than 50 mph. if the vehicle reaches 75 miles, it would immediately decrease in speed to 5 mph. the vehicle…”
- NHTSA complaint ODI #11695209 (filed 10/23/2025): “We believe that it is the park sensor in the column . when you place the truck into park, the screen displays the words shift to park period and the dinger.inside the truck continues to ding for a long time, even with opening and closing the door ... the truck is actually in park, so it does not mov…”
- NHTSA complaint ODI #11679809 (filed 08/11/2025): “The tailgate on my truck is electrically opened & closed. i've been having trouble with the tailgate opening randomly, even while driving. this has happened multiple times and can create a very dangerous situation, especially if i'm hauling something in the bed of the truck and it could possibly fal…”
Likely causes
These complaints do not establish a single root cause; read the examples above and get a diagnosis.
Fix, in plain English
No single fix is established by these reports. Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer about technical service bulletins (TSBs) or extended warranty coverage, then have the system diagnosed.
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 for this issue. Get a written quote after diagnosis.
Typical parts (search links, no affiliate codes)
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