Fuel Control: Notes
WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 2003 Hummer H2, 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 GMC Sierra, and 2003 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.
The PCM, using input signals, determines adjustments to the air/fuel mixture to provide the optimum ratio for proper combustion under all operating conditions. Fuel control systems can operate in the open loop or closed loop mode.