Crankshaft Position Sensor - Arctic Cat Sno Pro 120 2011 Service Manual

On the 500 cc, the injectors are coded with letters (A-B-
C). When replacement of a fuel injector is necessary, the
injector must be replaced with an injector of the same
code letter.
CAUTION
Do not replace an injector with one of a different letter.
Severe engine damage may occur.
500 cc
On the 600/800/1000 cc, the injectors are coded with
symbols ( - - ) and are color-coded yellow and green.
  
When replacement of a fuel injector is necessary, the
injector must be replaced with an injector of the same
code symbol and color.
CAUTION
Do not replace an injector with one of a different code
symbol or letter. Severe engine damage may occur.
600/800/
1000 cc
FUEL PRESSURE REGULATOR
The fuel pressure regulator is located in the fuel pump.
The fuel pressure regulator maintains the fuel pressure at
a constant specified level.
FUEL PUMP CIRCUIT
The fuel pump and its circuit are provided with current
from the fuel pump coil on the stator.
For this circuit to function correctly, five components must
be properly functioning. Check the following components
before considering the fuel pump assembly to be defective.
A. Fuel pump coil - see coil test procedure.
B. Emergency stop switch and ignition switch
must be ON.
4-16
C. Fuel pump - see fuel pump test procedure.
D. Wiring harness and connectors - clean the con-
nectors and test the harness.
E. ECU.

CRANKSHAFT POSITION SENSOR

(1100 cc)
This sensor measures the location in degrees of rotation
of the crankshaft. A 15° resolution exists between sig-
nals. The signal is triggered by the metal rectangles on
the outer surface of the flywheel as they pass by the sen-
sor. The sensor gives the ECU the location of the crank-
shaft at a given point in time. The ECU processes the
information and uses it in many different types of calcu-
lations. For example, the sensor can be used for RPM,
and it can also be used to determine the rate of accelera-
tion of the crankshaft.
CAMSHAFT POSITION SENSOR
(1100 cc)
This sensor tells the ECU which stroke the engine is on.
IO031A
Because the 4-stroke engine operates on a 720° cycle, the
piston is at TDC twice per cycle - once on the exhaust
stroke and once on the compression stroke.
MANIFOLD ABSOLUTE PRESSURE
(MAP) SENSOR (1100 cc)
This sensor measures pressure in the intake manifold
when the engine is running. The ECU uses this sensor to
aid in calculating the required fueling. For the base fuel
map, the 1100 cc non-turbo relies on the MAP sensor
only for low throttle openings. After a given throttle
opening is reached, the ECU switches to the TPS sensor
for its main fuel map. The 1100 cc turbo relies entirely on
the MAP sensor and only uses the TPS for its main fuel
map if the MAP sensor should fail. The ECU uses the
MAP sensor for many other calculations, but the base
fuel map is the main one.
WASTEGATE CONRTOL VALVE
(1100 cc Turbo)
The wastegate control valve adjusts the wastegate posi-
tion based on input from the ECU. The wastegate does
not require any input from the ECU to operate at base
boost levels. In areas of operation where the ECU will
allow the turbo to exceed base boost, the wastegate con-
FS025
trol valve bleeds some of the pressure that would typi-
cally be used to open the wastegate via the wastegate
diaphragm port on the turbo. By bleeding this pressure,
the wastegate is set at a lower opening thereby allowing
more exhaust gas to pass by the turbine increasing the
boost level.
KNOCK SENSOR (800 cc)
This sensor senses and controls engine knock or detona-
tion. The knock sensor assesses structure borne noise
(vibrations) caused by rapid pressure rises (detonation) in
either cylinder and performs calibration adjustments to
the necessary cylinder via the ECU limiting damage to
internal engine components. Detonation can be caused by
many variables including poor fuel quality, lean operat-
ing conditions, or modified engine components/systems.
Manual
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