Page 519 - Manual Oficina Polaris RZR XP 1000 17-18

ELECTRICAL

COOLING SYSTEM

FAN CONTROL CIRCUIT OPERATION / ENGINE COOLANT TEMPERATURE
TESTING SENSOR (ECT) OVERVIEW
Power is supplied to the fan via the Orange/Black wire Mounted in the thermostat housing, the engine
when the relay is ON. The ground path for the fan motor temperature sensor q measures coolant temperature.
is through the Brown harness wire. Refer to Relay The engine temperature sensor is a Negative
Operationpage later in this chapter for more Temperature Coefficient (NTC) type sensor, as the
information on fan functions. temperature increases the resistance decreases.

CAUTION
Keep hands away from fan blades during operation.
Serious personal injury could result.

NOTE
The fan may not function or operation may be delayed if
coolant level is low or if air is trapped in the cooling
system. Be sure cooling system is full and purged of air.

FAN CONTROL CIRCUIT BYPASS TEST
1. Disconnect harness from coolant temperature
sensor on the engine cylinder head (see Engine
Coolant Temperature Sensor (ECT) Overview Coolant passes through the thermostat housing and by
outlined in this chapter). the sensor probe, varying a resistance reading which is
relayed to the ECU. This signal is processed by the ECU
2. With the transmission in Park, start the engine. After and compared to its programming for determining the
a few seconds, the fan should start running and the fuel and ignition requirements during operation. The ECU
“Check Engine” indicator should display on the also uses this signal to determine when to activate the
instrument cluster. This indicates all other cooling fan during operation.
components are working properly.
3. If the fan does not run or runs slowly, check the fan ECT SENSOR TEST
motor wiring, ground, motor condition, circuit breaker To quickly rule out other components and wiring related
and mechanical relay for proper operation. Repair or to the ECT, disconnect the harness from the ECT sensor
replace as necessary. If the fan runs with the sensor and start the engine. After a few seconds, the fan should
harness disconnected, but will not turn on when the turn on and the “Check Engine” indicator should display
engine is hot, check the coolant temperature sensor on the instrument cluster. This indicates all other
and connector terminals.
components are working properly.

11

Polaris dealers can test the sensor by using Digital
Wrench® Diagnostic Software (dealer only).

9928492 R06 - 2017-2018 RZR XP 1000 / XP4 1000 Service Manual 11.51
© Copyright Polaris Industries Inc.