I've only had my tug for 2 weeks. It's a 2014. Generator with 29 hours. Has good exhaust flow but shuts down after 30 seconds ( no load on it) with low frequency error code. Changed fuel filter .. no help. Starts up easily then shuts down in 30 secs. Does not register any power production on @ ac panel. Frequency stays on zero the whole 30 seconds. Plenty of fuel and oil level perfect. Any ideas?