2025 GMC Sierra 1500: Power Train complaints
Owner-reported issue (NHTSA complaints, not a recall)
Symptoms
NHTSA has 26 owner complaints for the 2025 GMC Sierra 1500 that list the power train component. Complaints are individual owner reports, not verified defects.
Examples:
- NHTSA complaint ODI #11769463 (filed 10/06/2026): “I was driving at 70 mph on the highway. i heard clunk and then rattling and saw smoke while losing power. check 4wd warning illuminated. came to stop in busy traffic and where i first parked on shoulder, saw shoulder of roadway smoking and on fire. i pulled forward 100 or so feet slowly while hea…”
- NHTSA complaint ODI #11765016 (filed 09/17/2026): “The contact owns a 2025 gmc sierra 1500. the contact stated that while driving approximately 5 - 10 mph, the vehicle went into limp mode and failed to properly accelerate, and the transmission unexpectedly downshifted. there was an electrical malfunction, which caused the transmission to downshift. …”
- NHTSA complaint ODI #11760587 (filed 08/29/2026): “Engine started knocking at 18k miles and took to dealer and they found metal in the filter and installed a new engine and also replaced the midplate gasket on the valvebody due to a harsh downshift without codes in the system this engine is going on 2k miles and it seems to be fine now but the probl…”
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: Pro
Diagnosis needs a scan tool; repair or replacement needs a lift, transmission jack and the manufacturer's fluid fill/relearn procedure. (Our assessment.)
Cost
No sourced cost range for this issue. Get a written quote after diagnosis.
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