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• When engine has reached operating temperature, the PCM will begin monitoring O2S sensor input. The sys- IDLE MODE When the engine is at operating temperature, this is a Closed Loop mode. At idle speed, the PCM receives inputs • Air conditioning select signal (if equipped) • Air conditioning request signal (if equipped) • Battery voltage • Engine Coolant Temperature (ECT) sensor • CranKshaft Position (CKP) sensor • Intake manifold Air Temperature (IAT) sensor • Manifold Absolute Pressure (MAP) sensor • Throttle Position Sensor (TPS) • Camshaft position sensor signal • Battery voltage • Park/neutral switch (gear indicator signal—auto. trans. only) • Oxygen sensors Based on these inputs, the following occurs: • Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control injection • The PCM monitors the O2S sensor input and adjusts air-fuel ratio by varying injector pulse width. It also • The PCM adjusts ignition timing by increasing and decreasing spark advance. • The PCM operates the A/C compressor clutch through the A/C compressor clutch relay. This is done if A/C has CRUISE MODE When the engine is at operating temperature, this is a Closed Loop mode. At cruising speed, the PCM receives • Air conditioning select signal (if equipped) • Air conditioning request signal (if equipped) • Battery voltage • Engine Coolant Temperature (ECT) sensor • CranKshaft Position (CKP) sensor • Intake manifold Air Temperature (IAT) sensor • Manifold Absolute Pressure (MAP) sensor • Throttle Position Sensor (TPS) • Camshaft position sensor signal • Park/neutral switch (gear indicator signal -auto. trans. only) • Oxygen (O2S) sensors Based on these inputs, the following occurs: • Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then adjust the injector • The PCM monitors the O2S sensor input and adjusts air-fuel ratio. It also adjusts engine idle speed through • The PCM adjusts ignition timing by turning the ground path to the coil(s) on and off. • The PCM operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected 8E - 156 ELECTRONIC CONTROL MODULES KJ |