Engine Start-Up

This is an Open Loop mode. The following actions occur when the starter motor is engaged:

- If the engine controller receives a distributor signal, it will energize the auto shutdown (ASD) relay. This supplies battery voltage to the fuel pump, fuel injector, ignition coil, and oxygen sensor heating element. If the engine controller does not receive a distributor input, the ASD relay will not be energized.

- The engine controller compares the current MAP value with the atmospheric pressure value it received during the Key-On mode. This is done when the engine is operating and idling within ±64 rpm of the target rpm. If a minimum difference between the two is not detected, a pneumatic fault code is set into memory.

Once the ASD relay has been energized, the engine controller:

- Supplies a ground path to the injectors. 5.9L engines are pulsed 8 times instead of the normal 4 times.

- Determines injector pulse width based on coolant temperature, barometric pressure (MAP sensor), and number of engine revolutions since cranking was initiated.

- Monitors coolant temperature sensor, distributor pick-up, MAP sensor, throttle body temperature sensor and throttle position sensor. The engine controller determines correct ignition timing based on these inputs.