DTC P1621-P1622: Security Signal Malfunction: Description

When ignition is turned to ON position (power-up), a coded signal is sent to the ECM to enable the fuel system. When coded signal is received, ECM will perform a MIL (Check Engine) bulb check. If MIL does not illuminate during power-up, vehicle may be immobilized. If the vehicle is fully immobilized, ECM will disable the starter relay and the fuel injectors (preventing vehicle from being hot-wired).