Cannondale ATV Owner's Manual page 126

Components have been removed for this photo.
1. MC1000 ECU
2. Air pressure sensor hose (from airbox)
3. Data interface connector
4. ECU power relay
124
Barometric pressure sensor
The intake air pressure (barometric) sensor is built into
the ECU and is connected to the airbox plenum by a
narrow hose. The sensor measures the air pressure in the
airbox. Using this information the ECU determines the air
density, and when other inputs are added to the ECU, the
engine load is calculated. This information is then used to
adjust the amount of injected fuel to match the prevailing
conditions.
Crankshaft position sensor
The crankshaft position sensor is located in the
generator housing. This sensor detects movement of a
toothed wheel that is molded into the flywheel and attached
to the right side of the crankshaft. The wheel has a 36-
tooth pattern. The teeth are evenly spaced with the
exception of one triple length tooth next to one triple length
gap. Every time this tooth/gap passes the sensor the ECU
interprets it as bottom dead center (BDC). The ECU uses
this information to determine engine speed and crankshaft
position in relation to the point where fuel is injected and
ignition of the air/fuel mixture occurs.
NOTE :
Metallic debris or other contaminants on the sensor tip
will affect the sensor.