Engine Temperature Sensor; Operation Overview; Engine Temperature Sensor Test; Engine Temperature Sensor Replacement - Polaris 2008 sportsman 800efi Service Manual

FUEL INJECTION

ENGINE TEMPERATURE SENSOR

Operation Overview

Mounted on the cylinder, the engine temperature sensor
measures coolant temperature. The engine temperature sensor
is a Negative Temperature Coefficient (NTC) type sensor, as the
temperature increases the resistance decreases.
Refer to Chapter 10 for testing. Standard resistance readings
according to temperature:
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 it's
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. If for any
reason the engine temperature sensor circuit is interrupted, the
fan will default to "ON".
4.18

Engine Temperature Sensor Test

Engine Temperature Sensor
To quickly rule out other components and wiring related to the
ETS, disconnect the harness from the ETS. The fan should turn
on and 'HOT' should indicate on the instrument cluster. This
indicates all other components are working properly.
Refer to Chapter 10 for ETS testing. Polaris dealers can also test
the sensor by using the Polaris Digital Wrench' Software (dealer
only). Refer to the Digital Wrench' Software Manual for more
information.
Table 4-1: ETS Resistance Readings
°F
T
EMPERATURE
(°C)
68 °F (20 °C)
212 °F (100 °C)

Engine Temperature Sensor Replacement

1. Drain coolant to level below sensor
2. Disconnect sensor from engine harness.
3. Using a wrench, remove and replace the sensor, applying
a light coating of thread sealant to aid installation.
4. Torque the sensor to specification.
Engine Temperature Sensor Torque:
18 ft. lbs. (25 Nm)
R
ESISTANCE
2.5 kΩ ± 6%
0.186 kΩ ± 2%
= T