Engine Warm-Up

This is an Open Loop mode. The following inputs are received by the engine controller:

^ Coolant temperature

^ Idle contact switch (closed throttle switch)

^ Manifold absolute pressure

^ Engine speed (distributor pick-up)

^ Throttle body temperature sensor

^ Throttle position

^ Park/neutral switch (auto trans)

^ A/C switch

^ Battery voltage

^ Vehicle distance (speed) sensor

The engine controller provides a ground path for the injectors to precisely control injector pulse width. This is done by switching the ground on and off. On 5.9L engines, the injectors are fired 4 times per engine revolution. The engine controller adjusts engine idle speed, throttle stop angle, and ignition timing.