[gmtech1]

This code is for the mode control switch for the t/case (select switch). Being as it is an intermittant condition, check the connector at the switch and the t/case module. The module is loctaed behind the panel, under the right side of the dash at the base of the "A" pillar. It is known for getting water in the connector. If it all looks ok, you may need the problem to get more consistant in order to diagnose.