Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hi there, I am Cam. There may be aftermarket security systems in place in the truck, however there is still the factory theft deterrent built into the vehicle's computer system. So the indicator you are seeing is normal sign that the factory system is operational. The factory system prevents the injectors from operating unless a key is used to turn the ignition cylinder. So it prevents someone from hotwiring the truck.