Engine Warm-Up

This is an open loop mode. PCM determines injector pulse width using input information from battery voltage, CMP sensor, CKP sensor, ECT sensor, IAT sensor, MAP sensor and TP sensor. PCM also monitors A/C request and P/N switch (A/T only) for fuel calculation. PCM controls engine idle speed through IAC motor. PCM controls ignition timing based on CKP sensor input.

PCM also operates A/C compressor clutch (if A/C is requested) through A/C clutch relay. When engine reaches operating temperature, PCM will begin monitoring HO2S input and go into closed loop operation.