07 chevy avalanche keyless entry system acts like it falls asleep.WHY??? on 2007 Chevrolet Avalanche

after exiting the vehicle the factory keyless remote will lock/unlock and start,30 seconds goes by and the system becomes faulty,nothing works,until you unlock the door with the key the system will work for another 30 seconds or so..please help

Asked by for the 2007 Chevrolet Avalanche
have the anti theft module codes scanned and post so we can adv
1 more answer
possible anti-theft module issue...recommend dealership