NHTSA Complaint #11714544 — 2020 GMC TERRAIN

I own a 2020 GMC Terrain with approximately 110,000 miles. While driving in winter, the vehicle suddenly lost cabin heat and defrosting capability. The temperature gauge began fluctuating and the cooling fans continued running after the vehicle was shut off. A mechanic diagnosed the cause as a cracked radiator that allowed coolant to leak out, which is a known frequent failure on this model. Because the heater stopped working in sub-freezing temperatures, this created a safety hazard due to lack of defrosting and heat while driving. The failure occurred without warning, and no coolant warning light was displayed before the heater stopped working. The vehicle was not overheating at the time, but the loss of heat and defrost made winter driving unsafe.