Hyundai Repair Questions? Ask a Mechanic for Answers ASAP
Ok, based upon the symptoms, I suspect that the ETACS control module is faulty. This is the electronics time alarm control system, which is everything tied into the alarm and immobilizer system.
Unfortunately there is no at home fix for this. The ETACS control module will need to be replaced and the new one programmed to your son's vehicle using a dealer level scan tool and software.