Snowmobile Polaris Two Stroke (2007 year). Manual

11.20

BATTERY & ELECTRICAL SYSTEMS

CLEANFIRE™ FUEL INJECTION

System Overview

The 2007 Cleanfire™ fuel Injection system is a battery-less
engine management, capacitive discharge ignition, four fuel
injector engine management system.

System components include:

• ECU: The ECU controls the ignition / fuel injection

angles, chassis / battery relays, and supplies the MFD
gauge with tachometer / water temp. / PERC / HOT /
DET / diagnostic information.

• Stator: The stator consists of a lighting charge coil,

ignition exciter coil, fuel injector charge coil and two
independent external crank position (two and five
pulse) coils.

• Flywheel: The CFI flywheel houses the magnets for

energizing the stator windings as well as two
independent encoder ribs. The set of two encoder ribs
are spaced 180 degrees apart from each other and
provide RPM information required at engine start up. A
set of five encoder ribs is responsible for crank angle
detection, speed, and direction information.

• Regulator / Rectifier: Responsible for converting Vac to

Vdc for the chassis and battery (electric start) circuits.
Regulates voltage to 14.5 Vdc. Also supplies fuel
injector “boost” power when engine RPM is 700 RPM
or less.

• Capacitor: The capacitor suppresses voltage spikes and

ensures consistent voltage throughout the chassis
(RED/WHT) circuit.

• Chassis Relay: The chassis relay is activated by the

ECU at approximately 950 RPM. Below 950 RPM, all
power supplied by the regulator / rectifier (RED circuit)
is used to power the ECU and fuel pump.

• Ignition Coils: Provide ignition energy to each spark

plug. Both coils are fired at the same time.

• Fuel Injectors: CFI uses one set of full load injectors

(located in the crankcase), and one set of part load
injectors (located in each cylinder’s transfer port). The
full load injectors are always used, while the part load
injectors are used during mid to high RPM transitions.

• Detonation Sensor: Located on the cylinder head, the

detonation sensor transforms internal acoustic
information in a signal the ECU uses to determine the
amount of engine knock.

• Exhaust Valve Solenoid: Activated by the ECU, the

solenoid controls the VES venting. When powered, the
vents are closed, keeping the exhaust valves down.
When power is removed, the exhaust valves are
allowed to open.

• Throttle Position Sensor (TPS): The TPS relays the

position of the throttle plates (operator throttle input) to
the ECU.

• Coolant Temperature Sensor: Relays the engine

temperature to the ECU.

• Exhaust Temperature Sensor: Relays the temperature of

the exhaust pipe to the ECU.

• Temperature / Barometric Air Pressure (T-BAP)

Sensor: Relays the current intake air temperature and
ambient air pressure to the ECU. The sensor is located
on the airbox.

• Vehicle Speed Input: The ECU monitors the vehicle

speed supplied by the vehicle speed sensor.

• Fuel Pump: Supplies fuel to the fuel injectors. Power to

the fuel pump is supplied by the regulator / rectifier.

• Diagnostic Connector: The ECU can communicate with

the Polaris Digital Wrench software and can be re-
flashed, monitored and will display trouble codes.

Snowmobile Polaris Two Stroke (2007 year). Manual - part 70