8-VALVE 1.4
ENGINE
FIAT PUNTO TRAINING OUTLINE
Fiat Auto S.p.A.
After Sales Training
4.5.13 Knock control
The purpose of this strategy is to detect any knock condition by processing the signal from the
respective sensor.
This strategy continuously compares the signal from the sensor with a threshold value (which
is continuously updated) to allow for basic noise levels and engine ageing.
If the system recognizes that knock is present, the strategy will act so as to reduce the ignition
advance until the phenomenon disappears. Next, the advance will be gradually restored up to
the base value or until the phenomenon occurs again.
In particular, the advance increases are implemented in a gradual way, whereas the
decreases are implemented immediately.
During acceleration, the strategy will make use of a higher threshold, to allow for increased
engine noise under this condition.
Moreover, this strategy features a self-adapting function that memorizes, in a non-permanent
fashion, the advance reductions that might occur continuously, so as to adapt the advance to
the different conditions suffered by the engine (e.g. when fuel with a low octane number has
been used). The strategy is capable of resuming the advance to the threshold value stored in
the memory when the conditions that caused reduction to occur are not present any more.
gb Fiat Grande Punto OK
291 / 532
© 2004 Fiat Auto S.p.A. – All rights reserved