Tl* the contact owns a 2009 chevrolet tahoe hybrid. while driving 35 mph, the vehicle stalled and the check hybrid system error message displayed. the vehicle was restarted after two hours. the vehicle was taken to multiple independent mechanics who diagnosed that the hybrid coolant system failed and needed to be replaced. the vehicle was not repaired. the manufacturer was not notified of the failure. the failure mileage was 139,444.