The function of the fuel metering system is to deliver
the correct amount of fuel to the engine under all operating conditions.
Fuel is delivered to each cylinder by the fuel injectors. The fuel injectors
are controlled sequentially by the powertrain control module. The powertrain
control module bases the control of the fuel injectors on several important
engine parameters. These engine parameters include the following:
| • | The mass air flow (MAF) sensor |
| • | The intake air temperature (IAT) sensor |
| • | The engine coolant temperature (ECT) sensor |
| • | The throttle position (TP) sensor |
| • | The heated oxygen sensor (HO2S) |
Determining air density is critical to proper air/fuel management. Air
density is primarily derived from the MAF sensor input. For more information
on the operation of the MAF sensor, refer to
Information Sensors/Switches Description
. The complete fuel
metering system consists of the air/fuel delivery system as well as the
electronic control system. For information on the electronic control system
review the Powertrain Control Module (PCM) Description (PCM Function) and
Fuel Metering Modes of Operation
.
