Polaris 850 PRO-RMK 155 2.6" QD 2021, Manual

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4.6
9850060 R02 - 2020-2021 850 AXYS™ Long Track Snowmobile Service Manual
© Copyright Polaris Inc.
CLEANFIRE FUEL INJECTION (CFI) SYSTEM
CLEANFIRE FUEL INJECTION OVERVIEW
COMPONENT FUNCTION
ECU
The ECU controls the ignition / fuel injection angle, chassis/battery relays, and supplies the instrument
cluster with tachometer, water temperature, PERC, HOT, DET, and diagnostic information.
Stator / CPS
The stator is comprised of a 3-Phase circuit which adjusts stator voltage output – To Maximize Power
Output (Watts) Based on Fixed Calibration ‘Table / Chart’ in PBR Software.
The stator also provides two position sensors (2 and 5 tooth) that are used to determine engine speed
and direction.
Flywheel
Flywheel is forged. The flywheel features a 5 tooth (inner) encoder ring, and a 2 tooth (outer) encoder
ring. These encoder rings are used in conjunction with the two stator position sensors to determine
engine speed and direction.
Ignition Coil Packs Provide ignition energy to each spark plug. Both coils are fired at the same time.
Fuel Injectors This system features a set of fuel injectors mounted to the cylinders (ports).
Knock (DET) Sensor
Located on the cylinder head, the detonation sensor transforms internal acoustic information into a
signal the ECU uses to determine the amount of engine knock.
Electronic Exhaust Valve
(EV) Actuator
The EV Actuator is a servo motor that pushes and pulls the exhaust valve cable to close and open the
exhaust valves. The ECU drives the position of the EV Actuator using a PWM signal. The actuator
supplies the PWM converter with a PWM position and diagnostic signal. The PWM converter changes
these two PWM signals to analog signals and returns them to the ECU. The ECU uses these signals to
verify the position of the exhaust valves and system faults.
Throttle Position Sensor
(TPS)
The TPS relays the position of the throttle plates (operator throttle input) to the ECU.
Engine Coolant
Temperature (ECT)
Sensor
Relays the engine temperature to the ECU.
Exhaust Temperature
Sensor (EGT)
Relays the temperature of the exhaust pipe and resonator to the ECU.
Temperature / Manifold
Pressure Sensor Relays the current intake air temperature and ambient air pressure to the ECU. The sensor is located
on the airbox.
Vehicle Speed Sensor
The ECU monitors the vehicle speed supplied by the vehicle speed sensor. The sensor is mounted to
the chaincase next to the brake caliper. The brake disc has a series of drilled holes that the sensor
reads and the disc rotates.
Fuel Pump Supplies fuel to the fuel injectors. Power to the fuel pump is supplied by the PBR.
Diagnostic Connector
The ECU can communicate with the Polaris Digital Wrench® software and can be re-flashed,
monitored and will display trouble codes.
PBR
The PBR is located on a bracket secured to the over structure. The PBR is a power distribution device
for all major vehicle electrical circuits. It controls stator voltage and maximizes electrical power or
wattage output using its outputs. The PBR processes the stators 3 phase AC output power and controls
the output circuits including a 3 phase ground shunt circuit.
Electronic Oil Pump The electronic oil pump is powered by the RED circuit and driven by the ECU.
Fuel Pressure /
Temperature Sensor
The fuel pressure sensor provides the ECU with fuel pressure and fuel temperature information.
ENGINE ELECTRICAL