Thanks, I understand that, I had read somewhere the parking brake must be set, there can be restrictions in programming that have nothing to do with the actual hardware, (an example is if there is a MIL light the truck will not remotely start or at least keep running even though the remote start circuit has nothing connected to the MIL) It could of course simply be that it is "suggested" that the parking brake be set and that got converted by someone into it "must" be set.This from the instructions for the BD High Idle kit. Shows the circuit only goes to the ECM.
High Idle Control Chevy LBZ Duramax 2006-2007 | 1036606
For when days are short and the nights are cold, you want your engine to heat up quicker use the Duramax LBZ High Idle Control for the Chevy 2006-2007us.bddiesel.com
They only ask you to set the Parking brake when using the feature for safety and not to depress the brake pedal. I am just guessing the signal cancels out the PTO function so its not active if you put it in gear.
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