This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake valve.

The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing control solenoid valve depending on driving status. This makes it possible to control the shut/open timing of the intake valve to increase engine torque in low/mid speed range and output in high-speed range.

The intake valve timing control solenoid valve changes the oil amount and direction of flow through intake valve timing control unit or stops oil flow. The longer pulse width advances valve angle. The shorter pulse width retards valve angle. When ON and OFF pulse widths become equal, the solenoid valve stops oil pressure flow to fix the intake valve angle at the control position.

The Manifold Absolute Pressure sensor (MAP) provides instantaneous manifold pressure information to the engine's electronic control unit (ECM). The data is used to calculate air density and determine the engine's air mass flow rate, which in turn determines the required fuel metering for optimum combustion (see stoichiometry). A fuel-injected engine may alternately use a MAF (mass air flow) sensor to detect the intake airflow. A typical configuration employs one or the other, but seldom both.

In some vehicles the absolute pressure sensor is built into ECM

The intake air temperature sensor is built into mass air flow sensor. The sensor detects intake air temperature and transmits a signal to the ECM.

The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the temperature rise.

The heated oxygen sensor 2 is placed into the exhaust manifold. It detects the amount of oxygen in the exhaust gas compared to the outside air. The heated oxygen sensor 2 has a closed-end tube made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. The heated oxygen sensor 2 signal is sent to the ECM. The ECM adjusts the injection pulse duration to achieve the ideal air-fuel ratio. The ideal air-fuel ratio occurs near the radical change from 1V to 0V.

Indicates the engine coolant temperature rationality test has failed. The PCM logic that sets this DTC indicates that engine coolant temperature sensor (ECT or CHT) drifted higher than the nominal sensor calibration curve and could prevent 1 or more OBD monitors from executing. The PCM runs this logic after an engine offcalibrated soak period (typically 6 hours). This soak period allows the intake air temperature (IAT) and engine coolant temperature (CHT or ECT) to stabilize and not differ by more than a calibrated value. DTC P0116 is set when all of the following conditions are met:
- Engine coolant temperature at engine start exceeds IAT at engine start by more than a calibrated value, typically -1C (30F).
- Engine coolant temperature exceeds a calibrated value, typically 107 C (225F).
- The Fuel System, Heated Oxygen and Misfire Monitors have not completed. Calibrated timer to set DTC P0116 has expired.

Powertrain Control Module (PCM) or Electronic Control Module (ECM) checks the injectors circuit resistance and monitors the voltage drop during normal operation. The PCM/ECM will trigger the P0200 code when the resistance or voltage drop at the injectors is out of specifications.

Powertrain Control Module (PCM) or Electronic Control Module(ECM) checks the injectors circuit resistance and monitors the voltage drop during normal operation. The PCM/ECM will trigger the P0202 code when the resistance or voltage drop at the injector #2 is out of specifications.

Powertrain Control Module (PCM) or Electronic Control Module(ECM) checks the injectors circuit resistance and monitors the voltage drop during normal operation. The PCM/ECM will trigger the P0204 code when the resistance or voltage drop at the injector #4 is out of specifications.

Powertrain Control Module (PCM) or Electronic Control Module(ECM) checks the injectors circuit resistance and monitors the voltage drop during normal operation. The PCM/ECM will trigger the P0206 code when the resistance or voltage drop at the injector #6 is out of specifications.

Powertrain Control Module (PCM) or Electronic Control Module(ECM) checks the injectors circuit resistance and monitors the voltage drop during normal operation. The PCM/ECM will trigger the P0208 code when the resistance or voltage drop at the injector #8 is out of specifications.