Page 337 - Manual Oficina Polaris Sportsman 570 2014 a 2016

P. 337

FUEL SYSTEM

ELECTRONIC CONTROL UNIT (ECU)

ECU OVERVIEW RPM LIMIT
The ECU q is the central processing computer of the To prevent engine over-speed and possible failure, an
entire EFI fuel/ignition management system. During RPM limiting feature is programmed into the ECU. If the
operation, sensors continuously gather data which is maximum RPM limit is exceeded, the ECU suppresses
relayed through the wiring harness to input circuits within the injection signals, cutting off the fuel flow and retards
the ECU. Signals to the ECU include: ignition (on/off), the ignition timing. This process repeats it self in rapid
crankshaft position and speed (RPM), throttle position, succession, limiting operation to the preset maximum.
engine coolant temperature, intake air temperature,
intake manifold absolute pressure and battery voltage. 325 RPM Limit:
The ECU compares the input signals to the programmed Max RPM Limit - Fuel Injector Suppression.
maps in its memory and determines the appropriate fuel 8500 RPM (All Gears)
and spark requirements for the immediate operating
conditions. The ECU then sends output signals to set the
injector duration and ignition timing. 570 RPM Limit: 4
Max RPM Limit - Fuel / Spark Cutoff
7500 rpm (All Gears)

ECU PINOUTS
Refer to the 2nd page of each wiring diagram in this book
for ECU pin descriptions and wiring codes.

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
During operation, the ECU continually performs a performed. If a problem is encountered, and you
diagnostic check of itself, each of the sensors, and determine the ECU to be faulty, contact the Polaris
system performance. If a fault is detected, the ECU turns Service Department for specific handling instructions. Do
on the “Check Engine” light in the speedometer and not replace the ECU without factory authorization.
stores the fault code in its fault memory. Depending on The relationship between the ECU and the throttle
the significance or severity of the fault, normal operation position sensor (TPS) is very critical to proper system
may continue, or "Fail-Safe" operation (slowed speed, operation. If the TPS is faulty, or the mounting position of
richer running) may be initiated. A technician can the TPS to the throttle body is altered, the TPS must be
determine the cause of the “Check Engine” light by adjusted.
referencing the “Instrument Cluster Trouble Code
Display” and “Diagnostic Trouble Code Table” or by using For the purpose of troubleshooting, a known-good ECU
Digital Wrench®. The ECU requires a minimum of 7.0 from another Polaris Vehicle of the same model number
volts to operate. The memory in the ECU is operational may be used without system or engine component
the moment the battery cables are connected. damage.

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