I have not read the manual, this is a shot from the hip...... I would think that light touch is a very sensitive setting, the kind that go off when other cars exhaust noises get to close (mine sets off alarms)

and full shock is the less sensitive setting that will only go off when someone thumps/rocks/otherwise is molesting your car. Just my guess.
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2005 Torch red, predator 93 octane, K&N filter, Pypes true duals, Eibach Pro-kit springs,4.10 posi 8.8 rear end. GT fanblades with Eagle F1's, GT500 rear bumper/spoiler/front splitter