Intake air temperature sensor

INTAKE AIR TEMPERATURE SENSOR

The sensor, located on the injector turret above the throttle valve, consists of a resistance that alters its value in a manner inversely proportional to temperature.

On the basis of a voltage signal reaching the sensor, the ECU is able to detect the exact temperature of intake air.

RPM AND SYNCHRONISM SENSOR

The RPM and synchronism sensor (6) consists of a variable reluctance (i.e. a coil on a ferrous core) within which is set up a small electromotive force (e.m.f.) each time a crankshaft pulley tooth (2) passes the core. The e.m.f. set up in the sensor every 6° (i.e. the distance between the teeth centre-lines) for 58 teeth (each engine revolution), provides an exact method for measuring (using frequency of signal generated) engine rpm by the ECU. The signal interval generated by the lack of two teeth upon each pulley revolution informs the ECU about the current engine stage.

1. Synchronism tooth
2. Phonic wheel
3. TDC reference notch on phonic wheel
4. TDC reference notch on timing cover
5. Rpm and TDC sensor

PARTICULAR POSITIONS OF RPM AND SYNCHRONISM SENSOR

The phonic wheel consists of 58 teeth plus a space equivalent to the bulk occupied by two suppressed teeth.

The reference defined by the space of the two missing teeth is used as a basis for measuring the synchronism point (TDC).

The synchronism point is delimited by tooth (1). When this passes beneath the sensor, the crankshaft is located with piston pair 1-4 at 14° before TDC.

This signal is used by the ECU to compute the ignition advance angles.