Page 64 - Manual_Polaris_RZR_ProXP-20-21

GENERAL INFORMATION

CYLINDER MISFIRE DETECTION If a misfire code has been set and there is no observed
misfire, cycle the key and allow 4000 engine revolutions
NOTICE
to see if the check engine light turns off. If it does not turn
This process only applies to some MY15 and later off, diagnose by verifying the following items:
models.
Refer to this procedure only if one of the codes shown • Low battery voltage (loose connection, low charge,
below is displayed in Digital Wrench. bad battery)
• Faulty voltage regulator
The ECU monitors crankshaft speed via the crankshaft • Ignition Coil and connections are good
position sensor. A misfire will cause a fluctuation in
crankshaft speed. A code will set and turn on the check • Spark plugs wires are secure
engine light after an engine misfire threshold/rate is • The correct spark plugs are installed and the plugs are
detected that is above a pre-determined limit. This not fouled
threshold varies based on engine speed.
• Crankshaft Position Sensor tests good
One or more of the following codes will be set if a misfire
occurs: • Wiring to the Crankshaft Position Sensor, ECU and
Ignition Coil are not damaged. Chassis ground is clean
• P0301 (SPN 65591/FMI 7) Misfire Detected, Cylinder and tight
1 (MAG)
• Fuel pressure is within specification
• P0302 (SPN 65592/FMI 7) Misfire Detected, Cylinder
2 (PTO) • Fresh/good quality fuel is in the fuel tank
• P0314 (SPN 65590/FMI 7) Misfire Detected, Cylinder • Engine mechanical is good (leak down, timing)
Not Identified • Confirm the belt is in good condition, specifically
looking for signs of hour-glassing
Once a cylinder misfire code is set, the following events • Confirm primary clutch operation (worn/incorrect
will occur:
weights, loose spider/jam nut)
• Check Engine Light illuminates • Confirm secondary clutch operation (sliders, rollers,
• If the cylinder can be detected by the ECU (code helix)
P0301 or P0302), the ECU will deactivate the fuel
injector for that cylinder. This will remain in effect until
the key is cycled off and back on.

• If the cylinder with the misfire cannot be detected
(code P0314), the ECU will limit available power by
limiting how far the throttle plate opens.

One the key is cycled, the trouble code(s) will show
current but there will be no fuel injector deactivation or
throttle limitation unless the misfiring continues to occur.
The check engine light will remain illuminated until there
are 4000 engine revolutions (i.e. 4000 RPM for one
minute) without a significant misfire being detected.
Once this condition is met, the check engine light will turn
off and the code(s) will show as historic.

1.58 9930583 R01 - 2020-2021 RZR PRO XP / XP 4 Service Manual
© Copyright Polaris Industries Inc.