Electronic Control Unit (Ecu); Operation Overview; Ecu Service; Ecu Replacement - Polaris RZR 800 2013 Manual

ELECTRONIC CONTROL UNIT (ECU)

Operation Overview

The ECU 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 (on/off),
crankshaft position and speed (RPM), camshaft position
(MAG/PTO), throttle position,
temperature, intake air temperature, intake manifold
absolute pressure and battery voltage. The ECU
compares the input signals to the programmed maps in
its memory and determines the appropriate fuel and
spark requirements for the
conditions. The ECU then sends output signals to set the
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 in the speedometer 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
ELECTRONIC FUEL INJECTION
the ignition timing. This process repeats it self in rapid
succession, limiting operation to the preset maximum.
RZR 800 EFI RPM Limit:
Max RPM Limit - Injector and ignition suppression.
engine coolant

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.
immediate operating
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.
The relationship between the ECU and the throttle
position sensor (TPS) is very critical to proper system
operation. If the TPS is faulty, or the mounting position of
the TPS to the throttle body is altered, the TPS must be
adjusted.
For the purpose of troubleshooting, a known-good ECU
from another Polaris RZR EFI of the same model may be
used without system or engine component damage.

ECU Replacement

1. Remove the (2) retaining screws holding the ECU.
2. With the ignition turned off, disconnect the wire
3. To install, reverse the procedure and tighten screws
9924707 - 2013–2014 RZR 800 Service Manual
© Copyright 2013 Polaris Sales Inc.
• RZR: 6600 RPM (All Gears)
• RZR S / RZR 4: 6750 RPM (All Gears)
harness from the ECU.
to specification.
ECU Retaining Screws:
10 in-lbs (1.1 Nm)
4
4.13