8-VALVE 1.4
ENGINE
FIAT PUNTO TRAINING OUTLINE
Fiat Auto S.p.A.
After Sales Training
Operation
The molecules of a quartz crystal are characterized by electric polarization.
In rest conditions (A), the molecules doe not feature a peculiar orientation.
When the crystal is subjected to pressure or a collision (B), the molecules orient themselves:
the higher the pressure to which the crystal is subjected (quartz characteristic), the more
pronounced the molecule orientation.
Such orientation generates a voltage at the crystal ends. Therefore, such voltage is the result
of the vibrations generated by the burst in the various cylinders.
The reference wave amplitudes are mapped in the engine control unit (with correct engine
operation).
The engine control unit interprets the wave amplitudes differing from the reference ones as
failed ignition; therefore, it will actuate an emergency program.
A. Rest position
B. Position under pressure
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