Polaris RZR PRO XP 2020, Service Manual

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4.2
9850068 R01 - 2020-2021 RZR PRO XP / XP 4 Service Manual
© Copyright Polaris Industries Inc.
ELECTRONIC CONTROL UNIT (ECU)
ECU OPERATION OVERVIEW
The ECU
q
is the brain or central processing computer
of the entire EFI fuel/ignition management system.
During operation, sensors continuously gather data
which is relayed through the wiring harness to input
circuits within the ECU. Signals to the ECU include:
ignition power (on/off), barometric pressure, intake air
temperature, boost pressure, manifold absolute pressure
(load), engine coolant temperature, crankshaft position
and engine speed (RPM), throttle position and battery
voltage. The ECU compares the input signals to the
programmed maps in its memory and determines the
appropriate fuel and ignition requirements for the
immediate operating conditions. The ECU then sends
output signals to set injector duration and ignition timing.
During operation, the ECU continually performs a
diagnostic check of itself, each of the sensors, and
system performance. If a fault is detected, the ECU turns
on the “Check Engine” light on the instrument cluster and
stores the fault code in its fault memory. Depending on
the significance or severity of the fault, normal operation
may continue, or "Fail-Safe" operation (slowed speed,
richer running) may be initiated. A technician can
determine the cause of the “Check Engine” light by
referencing the “Instrument Cluster Trouble Code
Display” and “Diagnostic Trouble Code Table” or by using
Digital Wrench®. The ECU requires a minimum of 7.0
volts to operate. The memory in the ECU is operational
the moment the battery cables are connected.
To prevent engine over-speed and possible failure, an
RPM limiting feature is programmed into the ECU. If the
maximum RPM limit is exceeded, the ECU suppresses
the injection signals, cutting off the fuel flow and retards
the ignition timing. This process repeats it self in rapid
succession, limiting operation to the preset maximum.
RPM Limit:
8800
ECU SERVICE
Never attempt to disassemble the ECU. It is sealed to
prevent damage to internal components. Warranty is void
if the case is opened or tampered with in any way.
All operating and control functions within the ECU are
pre-set. No internal servicing or readjustment may be
performed. If a problem is encountered, and you
determine the ECU to be faulty, contact the Polaris
Service Department for specific handling instructions. Do
not replace the ECU without factory authorization.
For the purpose of troubleshooting, a known-good ECU
from another Polaris
RZR of the same model may be
used without system or engine component damage.
ECU REPLACEMENT
Although the need for ECU replacement is unlikely, a
specific replacement procedure is required to ensure that
all essential data contained within the original ECU is
transferred to the replacement ECU.
NOTICE
Refer to this procedure and carefully follow all
instructions provided in Digital Wrench®.
1. Carefully follow the ECU replacement instructions
provided in Digital Wrench® to ensure that all
essential data contained within the original ECU is
transferred to the replacement ECU.
2. Remove the plastic cover
q
by pulling on the upper
tab.
ENGINE ELECTRICAL