Checking the resistance

The sensor can be rapidly put out of action by even small amounts of lead in the fuel.

Checking the resistance

The resistance of the heater and the sensor can be measured by disconnecting the connector and connecting an ohmmeter as shown in the diagram.

Resistance = 500-1000 ohm at 20°C

SPEEDOMETER SENSOR

The speedometer sensor (vehicle speed sensor) is positioned at the differential output, by the left driveshaft coupling and transmits information concerning the vehicle speed to the control unit: the signal is also used for the operation of the speedometer.

The sensor is the Hall effect type (see paragraph on "engine timing sensor") and is calibrated so that each impulse corresponds to a distance of one metre; it is possible to know the speed of the vehicle from the frequency of the impulses.

The control unit uses this information for improving the management of the engine idle adjustment actuator and for the CUT-OFF strategy.

Wiring connector

The numbers indicate the corresponding control unit pins