Throttle valve position sensor

THROTTLE VALVE POSITION SENSOR

This consists of a potentiometer whose mobile part is controlled by the throttle valve spindle.

During operation, the ECU supplies the potentiometer with a voltage of 5 Volts applied to pins (1) and (2).

A voltage inversely proportional to throttle opening position builds up on pin 3. According to the voltage sent by pin 3, the ECU recognises the throttle valve opening condition and corrects mixture concentration accordingly.

With the throttle closed, an electrical signal of about 0.5 Vots is sent to the ECU, which recognises idling and cut-off conditions (differentiating between them on the basis of engine rpm).

The sensor automatically recognises throttle closure contact position by means of a self-adaptive function. This eliminates potentiometer regulation operations and allows wear on throttle closure position to be monitored if necessary.

COOLANT TEMPERATURE SENSOR

The sensor is fitted with its sensitive part in contact with the coolant. It provides the ECU with a voltage that varies according to engine temperature in order to correct air output information.

On the basis of a signal received by the sensor, the ECU is able to pilot fuel injection for longer in order to ensure the enrichment necessary for compensating for fuel loss due to the condensation of fuel particles in the inlet ducts while the engine is warming up.

This sensor therefore ensures safe engine operation in the stage following start-up by adding further enrichment with intensity and duration dependent on coolant temperature; this also permits correct engine operation during acceleration with the engine cold.