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[DieselSVT]

I would think you need to recycle the ignition source after an aux shutdown occurance. The fact that you say sometimes it starts again sometimes it doesn't has me second guessing myself however. You take the circuit and "unground" it and try to start again without recycling the ignition? Do you have a Check Engine Light and Stop Engine Light wired up? If so are they still lit while you are trying to start it?

I looked in the application and installation manual and it doesn't say any specific logic on the way the feature works such as restart etc...Other than what the function can be used for.