I have a 2005-2500 Chevy Cargo Express and a 2006-1500 Chevy Cargo Express and neither have a "security" light that comes on when the switch is made, never has. Recently all the evidence suggest that the 2006 van has a passlock Ignition Lock Housing fault, yet no "security" light has come on. I've performed all the prescribed ignition tests and have come to the conclusion that "engine cranks" but will not start problem lies with the Passlock sensor, yet no sucerity light.
neither of my Express vans have a security light. on 2006 Chevrolet Express 1500
Mechanic needs to check it.