2006 GM Truck/Van Ignition Lock Cylinders

[ktmlew]

Installed a lock cylinder today from Advance. Cranked and started at first attempt. No programming needed? The "security" light lock symbol was on and would do the the prove out. Never did blink or do any "programming". I started truck 5-6 times after leaving switch on while reassembling column covers. Appeared to be fine. I thought they had to relearn the key?

[amailloux]

The pats sensor is in the lock cylinder case up to the gmt 900 trucks. There is no transponder in the key head. There is a magnet that rotates past a hall sensor to trigger the theft challenge. It the lock sensor is forced to rotate, or the ignition switch jumped without the magnet triggering the hall and sending the voltage, a theft event is triggered. Just below the head of the key look for a plus, or a circle plus. These oe keys have transponders in them and will need learned.

[ktmlew]

The pats sensor is in the lock cylinder case up to the gmt 900 trucks. There is no transponder in the key head. There is a magnet that rotates past a hall sensor to trigger the theft challenge. It the lock sensor is forced to rotate, or the ignition switch jumped without the magnet triggering the hall and sending the voltage, a theft event is triggered. Just below the head of the key look for a plus, or a circle plus. These oe keys have transponders in them and will need learned.

OK. Thanks. I read that somewhere but your explanation is MUCH more clear. Servicing 90+ GM tricks/vans and lock cylinders are starting to die. Some are well over 300K miles.