Cooling System; Coolant Temperature Sensor - Polaris RZR 900 2017 Service Manual

ELECTRICAL

COOLING SYSTEM

COOLANT TEMPERATURE SENSOR

Engine Coolant Temperature Sensor (ECT) Overview
Mounted in the thermostat housing, the engine
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temperature sensor measures the coolant
temperature. The engine temperature sensor is a
Negative Temperature Coefficient (NTC) type sensor, as
the temperature increases the resistance decreases.
Coolant passes through the thermostat housing 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
cooling 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.
Refer to Chapter 3 and 10 for additional ECT sensor
information. Polaris dealers can test the sensor by using
Digital Wrench® Diagnostic Software (dealer only).
12.30
ECT Sensor Replacement
1. Remove the throttle body / ETC. (see Chapter 4 –
ETC Replacement page 4.7).
2. Be sure the engine has cooled enough to work on.
3. Disconnect the vehicle harness from the ECT sensor.
4. Drain the coolant so the level is below the sensor
(see Chapter 2 – Coolant Drain / Fill page 2.40).
5. Using a wrench, remove and replace the sensor
applying a light coating of thread sealant to aid
installation.
6. Torque the new ECT sensor to specification and
connect the vehicle harness to the sensor.
7. Reinstall the throttle body
8. Add the required amount of coolant and bleed the
system (see Chapter 3 – Cooling System Bleeding
page 3.12).
9930588 R02 - 2017-2020 RZR 900 900/S 900/S4 1000/S 1000/S4 Service Manual
TORQUE
ECT Sensor:
17 ft-lb (23 Nm)
© Copyright Polaris Industries Inc.
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