Fuel Control: Notes

PCM controls fuel system by varying fuel injector pulse width and duration based upon sensor input signals. If feedback system does not function properly, check A/C clutch signal, battery voltage, closed throttle position switch, Crankshaft Position Sensor (CKP), EGR temperature sensor, Engine Coolant Temperature (ECT), Heated Oxygen Sensors (HO2S), ignition (START) signal, Mass Airflow (MAF) sensor, park/neutral switch, power steering pressure switch, secondary throttle sensor, sub-crankshaft position sensor, Throttle Position (TP) sensor, Vehicle Speed Sensor (VSS) input signals before replacing PCM.