The battery current sensor installed on the positive battery terminal detects the amount of current supplied from the alternator.

The intake air temperature sensor is built into the mass air flow meter and senses the intake air temperature.

A thermistor built in the sensor changes its resistance value according to the intake air temperature.

The fuel route switching valve changes the route of fuel discharged from the fuel pump to switch between the fuel transfer operation and priming operation.

The manifold absolute pressure sensor detects the intake manifold pressure by using the built-in sensor unit. The ECM determines the basic injection duration and injection advance timing based on the voltage output by the manifold absolute pressure sensor.

The two sensing chambers of the differential pressure sensor are mounted to monitor the pressure before and after the DPNR (*2) catalytic converter. The sensor itself is not located on the engine assembly in order to reduce the influence of vibration. The sensor is a semiconductor-type that is not influenced by exhaust gases.

The manifold absolute pressure sensor detects the intake manifold pressure by using its built-in sensor unit. The ECM determines the basic injection duration and injection advance timing based on the voltage output by the manifold absolute pressure sensor.

The two sensing chambers of the differential pressure sensor are mounted to monitor the pressure before and after the DPNR (*2) catalytic converter. The sensor itself is not located on the engine assembly in order to reduce the influence of vibration. The sensor is a semiconductor-type that is not influenced by exhaust gases.

The mass air flow meter uses a platinum hot wire. The mass air flow meter consists of a platinum hot wire, a temperature sensor and a control circuit installed in a plastic housing. The mass air flow meter works on the principle that the hot wire and temperature sensor located in the intake air by-pass of the housing detect any changes in the intake air temperature.

The exhaust fuel addition injector is mounted on the exhaust port of the cylinder head, and low pressure is provided to the injector by the feed pump in the supply pump. This injector adds fuel by a control signal from the ECM.

This injector is used for two different controls: DPNR catalyst regeneration and nitrogen oxides (NOx) reduction.

Under the DPNR catalyst regeneration control, the injector adds fuel to raise a catalyst temperature.

The ECM controls the internal fuel pressure of the common rail by opening and closing the pressure discharge valve. When sudden deceleration occurs, the internal fuel pressure will temporarily become higher than usual and combustion noise may result. Therefore the ECM will open the valve temporarily to discharge the excess pressure inside the common rail. Also, the pressure discharge valve opens when the engine switch is turned OFF to allow prompt discharge of the common rail internal pressure.