Intake air temperature sensor

The turbocharger used on this engine is IHI-VL7 type. It consists essentially of two impellers fitted to the same shaft.

One impeller, known as a turbine, is located on the exhaust manifold and turned by the kinetic energy and pressure of exhaust gases striking it.

The rotating turbine struck by gas also turns the other impeller, known as a compressor and located on the intake duct, at the same speed.

Due to its speed of rotation and the particular shape of its vanes, the compressor takes up air from outside and compresses it in the inlet manifold and then in the engine cylinder.

Cross section through turbocharger IHI-VL7
The coloured parts show the route taken by coolant from the engine.

INTAKE AIR TEMPERATURE SENSOR

The intake air temperature sensor is located on the intake manifold downstream of the throttle valve.

This sensor measures the temperature of turbocharged air taken into the cylinders.

Information sent to the ECU is used by the unit to limit turbo pressure if the air temperature reaches excessive levels.

ABSOLUTE PRESSURE SENDER UNIT (barometric capsule)

The absolute pressure sender unit is a sensor that sends the injection-ignition ECU information on changing barometric pressure conditions during vehicle use.

This sensor sends the ECU a signal proportional to the sensor input voltage and barometric pressure.

The information is used to limit turbo pressure at high altitude.

This strategy is necessary to protect against the danger of the compressor turbine turning too fast because rarified air at altitude and excessive performance demands by the driver could force the turbine to turn too fast before achieving the required turbo pressure.