The PCM controls the fuel injectors based on information it receives from several information sensors. Each injector is fired individually in engine firing order, which is called Sequential Multiport Fuel Injection. This allows precise fuel metering to each cylinder and improves driveability under all driving conditions.
The PCM has several operating modes for fuel control, depending on the information it receives from the sensors.
When the key is first turned ON, the PCM will turn on the fuel pump relay for approximately two seconds. The fuel pump runs and builds up pressure in the fuel system. The PCM then monitors the MAF, IAT, ECT, and TP sensor signal to determine the required injector pulse width for starting.
If the engine is flooded with fuel during starting and will not start, Clear Flood Mode can be manually selected. To select Clear Flood Mode, push the accelerator to Wide Open Throttle (WOT). With this signal, the PCM will completely turn Off the injectors and will maintain this as long as it sees a WOT condition with engine speed below 1000 RPM.