Polaris 2007 Sportsman 450 EFI, Service Manual

Page: 134 / 406

4.22
FUEL INJECTION
ENGINE TEMPERATURE SENSOR
General Information
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.
Coolant passes through the cylinder and by the sensor probe,
varying a resistance reading which is relayed to the ECM. This
signal is processed by the ECM and compared to it's
programming for determining the fuel and ignition
requirements during operation. The ECM 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”.
Engine Temperature Sensor Test
Polaris dealers can test the sensor by using the Polaris Digital
Wrench
™
Software (dealer only). Refer to the Digital
Wrench
™
Software Manual for more information.
To measure the sensor using an ohmmeter, place the tester leads
on each terminal an read the resistance with the sensor at an
ambient temperature of 68
°
F (20
°
C).
Engine Temperature Sensor Replacement
1. Disconnect sensor from engine harness.
2. Using a wrench, remove and replace the sensor, applying
a light coating of thread sealant to aid installation.
3. Torque the sensor to specification.
Engine Coolant Temperature Sensor (ECT)
Table 4-1: Resistance Readings
T
EMPERATURE
°
F (
°
C)
R
ESISTANCE
68
°
F (20
°
C) 37.3 - 39.2 k
Ω
= T
ETS Installation Torque:
18.5 ft. lbs. (25 Nm)