The code that you refer to seems like it is merely a fix (a kludge if you will) around a broken 'ac' switch. @tunerid would permit those various vehicles and docking stations setups a method to select unique parameters for a particular setup without user intervention. (If memory serves; Loren has two or more docking stations.)

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The actual tuner id could be from a pic programmed similarly to the one in pca's tuner kit.