2012 GMC Sierra 2500HD: Electrical System complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 11 owner complaints for the 2012 GMC Sierra 2500HD that list the electrical system component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11542551 (filed 09/05/2023): “Driving on the expressway around 60 mph when the truck went into limp mode slowing me down to 40 and then would not shift gears tcm went out gm told me that there is a big problem…”
- NHTSA complaint ODI #11536038 (filed 08/02/2023): “Failed transmission control module (24256861). while driving in the early morning hours (darkness) taking my child to school, i was navigating through a busy intersection when the vehicle surged and then made a loud metal on metal sound, feeling as if someone had struck me from behind. at that poin…”
- NHTSA complaint ODI #10850234 (filed 03/17/2016): “Tl* the contact owns a 2012 gmc sierra 1500. the contact stated that the dashboard near the passenger side air bag was fractured. the vehicle was taken to the dealer where it was diagnosed that the dashboard needed to be replaced. the vehicle was not repaired. the manufacturer was notified of the f…”
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.
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