Configuration Of Knock Sensors Parameters; Sensor Parameters - ECU Master EMU User Manual

CONFIGURATION OF KNOCK SENSORS PARAMETERS

EMU has the ability to work with common knock sensors and to take appropriate corrective actions
when knock is detected. Common correction strategies are to enrich the fuel dose and to retard
ignition timing. The EMU employs advanced knock processors designed for use with flat response
(wideband) knock sensors. Flat response knock sensors are able to capture much more
information than older style sensors, and advanced filtering and processing is performed by the
EMU in order to better detect knock. Connection for two-wire sensors is shown below. One-wire
sensors do not need a ground wire as the body of the sensor is grounded by mounting to the
engine block.
Knock sensors must be connected with shielded cables. Shielding must be
connected to ground on only one end.

Sensor parameters

PARAMETER
Knock
frequency
Gain
EMU
Knock sensor sample connection
DESCRIPTION
The engine knock characteristic frequency used to configure the band-pass
filter. This characteristic is different for every engine. It can be approximated
with the following equation:
Where D is cylinder diameter in millimeters
Knock sensor signal gain should be adjusted so that the Knock sensor value
parameter doesn't exceed 3V across the full RPM range during normal
combustion
Out
B2
B18
GND
ATTENTION !
Knock frequency (kHz) = 1800/(Pi * D)
Page 101
KS