Page 205 - Manual Oficina Polaris RZR XP 1000 17-18

FUEL SYSTEM

ELECTRONIC CONTROL UNIT (ECU)

OPERATION OVERVIEW ECU SERVICE
The ECU q is the brain or central processing computer Never attempt to disassemble the ECU. It is sealed to
of the entire EFI fuel/ignition management system. prevent damage to internal components. Warranty is void
During operation, sensors continuously gather data if the case is opened or tampered with in any way.
which is relayed through the wiring harness to input All operating and control functions within the ECU are
circuits within the ECU. Signals to the ECU include: pre-set. No internal servicing or readjustment may be
ignition power (on/off), intake air temperature, manifold performed. If a problem is encountered, and you
absolute pressure (load), engine coolant temperature, determine the ECU to be faulty, contact the Polaris
crankshaft position and engine speed (RPM), throttle Service Department for specific handling instructions. Do
position and battery voltage. The ECU compares the not replace the ECU without factory authorization.
input signals to the programmed maps in its memory and
determines the appropriate fuel and ignition For the purpose of troubleshooting, a known-good ECU
requirements for the immediate operating conditions. from another Polaris RZR of the same model may be
The ECU then sends output signals to set injector used without system or engine component damage. 4
duration and ignition timing.
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.

NOTE
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 black plastic cover by lifting up on the
During operation, the ECU continually performs a
diagnostic check of itself, each of the sensors, and tab.
system performance. If a fault is detected, the ECU turns 3. Remove the screws w that attach the ECU to the
on the “Check Engine” light on the instrument cluster and driver’s rear fender well.
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:
RZR 900: 8300
RZR 1000: 8800

9928492 R06 - 2017-2018 RZR XP 1000 / XP4 1000 Service Manual 4.11
© Copyright Polaris Industries Inc.