Inertial switch

INERTIAL SWITCH

In the front side of the driver’s seat there is a safety switch which is triggered in the case of an impact, cutting off the fuel pump connection to earth, thereby also the supply to the injection system.

A steel ball fitted in a taper housing is normally held in place by the force of attraction of an adjacent magnet. Under specific acceleration loads the ball releases itself from the magnetic force and gradually moves out of the taper support rising upwards following the angle of the taper. A quick snap connection is fitted above the ball which forms the normally closed (N.C.) electric circuit. When the mechanism is hit by the ball it changes position, from N.C. circuit to normally open circuit (N.A.), cutting off the fuel pump earth circuit. In the event of impact in any one of the three orthogonal directions, the switch will be triggered above 12 g peak equivalent to a speed of 25 kph. The switch can be reset pressing the pushbutton protected by a flexible cover (this also protects against foreign particles which might prevent the switch from operating or reprogramme it).

If after even a light crash, there is the smell of petrol or leaks are noted from the fuel supply system, do not reset the switch, but firstly seek the failure and repair it to prevent the hazard of fire. Conversely, if there are no leaks and the car can be restarted, press the pushbutton to reactivate the fuel pump.

REMOVAL/REFITTING

• Disconnect the battery (-) terminal.

1. Slacken the two fastening screws and remove the plastic cover protecting the inertial switch.

• Slacken the two fastening screws, disconnect the electrical connection and remove the inertial switch.

SPEEDOMETER SENSOR

REMOVAL/REFITTING

• Set the car on a lift.
• Disconnect the battery (-) terminal.

1. Disconnect the electrical connection of the speedometer sensor.
2. Raise the car and using wrench no. 1.822.161.000, slacken and remove the speedometer sensor.