Table of Contents
ELECTRONIC FUEL INJECTION
ENGINE COOLANT TEMPERATURE
SENSOR (ECT)
Operation Overview
Mounted on the cylinder head, the engine temperature
sensor measures coolant temperature. The engine
temperature
sensor
is
Coefficient (NTC) type sensor, as the temperature
increases the resistance decreases.
Coolant passes through the cylinder and by the sensor
probe, varying a resistance reading which is relayed to
the ECU. This signal is processed by the ECU and
compared to its programming for determining the fuel
and ignition requirements during operation. The ECU
also uses this signal to determine when to activate the
fan during operation.
ECT Sensor Test
To quickly rule out other components and wiring related
to the ECT, disconnect the harness from the ECT sensor
and start the engine. After a few seconds, the fan should
turn on and the "Check Engine" indicator should display
on the instrument cluster. This indicates all other
components are working properly.
4.40
a
Negative
Temperature
9924707 - 2013–2014 RZR 800 Service Manual
© Copyright 2013 Polaris Sales Inc.
Refer to Chapter 3 and 10 for additional ECT sensor
information. Polaris dealers can test the sensor by using
the Digital Wrench® Diagnostic Software (dealer only).
ECT Sensor Resistance Readings
Temperature °F (°C)
68 °F (20 °C)
86 °F (30 °C)
104 °F (40 °C)
122 °F (50 °C)
140 °F (60 °C)
158 °F (70 °C)
176 °F (80 °C)
194 °F (90 °C)
212 °F (100 °C)
ECT Sensor Replacement
1. Remove the driver and passenger seats.
2. Remove the rear service panel to access the ECT
sensor.
3. Drain coolant to level below sensor.
4. Disconnect sensor from engine harness.
5. Using a wrench, remove and replace the sensor,
applying a light coating of thread sealant to aid
installation.
6. Torque the sensor to specification.
ECT Sensor:
17 ft-lbs (23 Nm)
7. Add the required amount of coolant and properly
bleed the cooling system (see Chapter 3).
Resistance
2.5k Ω ± 6%
1.7k Ω ± 6%
1.2k Ω ± 6%
834 Ω ± 6%
596 Ω ± 6%
435 Ω ± 6%
323 Ω ± 6%
243 Ω ± 6%
186 Ω ± 6%
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