If the security is infact ok, check to see if there is a signal from the crankshaft position sensor. This sensor is what the computer uses for injector timing, as well as rpm for the tach and computer. Use your scan tool to look at engine speed reading, if it stays at 0 during cranking, the computer isn’t receiving that signal. Could be the sensor, could be the wiring from sensor to the computer, check them both.

Your sure the SECURITY Telltale isn't lit on the instrument cluster .
The SECURITY telltale appears on the message center inside the instrument cluster. If the SECURITY telltale flashes or if the SECURITY telltale lights continuously during the vehicle operation, refer to the system diagnosis.