Ignition Switch Off

This is an OPEN LOOP mode. When the key is placed in the OFF position, the engine controller removes the ground from the Auto Shutdown (ASD) and Fuel Pump relays. When the ASD and Fuel Pump relays are DE-ENERGIZED, no battery voltage is allowed to flow to the fuel pump, fuel injectors, ignition coil, or oxygen sensor heating element. When this occurs, all fuel injection, and other systems controlled by the SBEC, cease to function.