Turns out that there is some sort of connection to the "infotainment" software. I could not get the infotainment system to function properly for radio presets, recognizing me as the user, or many other functions. I could do all that but as soon as I restarted the vehicle, it returned to a default condition without having remembered anything I had set up. A trip to the dealer, saleswoman and 4 techs later - no solution. On star call was fruitless, finally a call to myChevy resulted in a 30 minute system restart procedure that cured the infotainment issue. When I got home and hooked to trailer the ITBC responded as it should. The myChevy tech said this is a known problem that occurs but infrequently.
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