SsangYong Actyon Sports II. Manual - part 73

06-9

2110-01

3. PWM (PULSE WIDTH MODULATION) ELECTRIC FAN 

OPERATION

1) Function

The PWM (Pulse Width Modulation) high capacity electric fan is installed instead of electric condenser 

fan to enhance the durability and controllability and reduce noise.

2) Mounting Location

PWM

Fan shroud

Electric fan

PWM unit

06-10

3) PWM Electric Fan

(1) Advantages and Disadvantages of the PWM Electric Fan

Advantages

▶

Enhanced A/C performance: at low speed, at 

idling, driving in city

Reduction of vibration/noise: fan activated by 

PWM only when necessary

Reduction of engine consuming power 

(V/Fan driving force) by 4 Hp - Cost saving

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Disadvantage

▶

Poor engine cooling perfomance at low and 

high rpm

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4) PWM (Pulse Width Modulation) Unit

It controls the time of the output voltage to control 

the fan motor speed independently.

Internal functions

▶

Motor power shutting-off function when 

overcurrent is applied

Adverse voltage prevention function

Detection function for the motor lock

Temperature detecting function: The electric 

fan operates at FULL speed to cool down 

the PWM unit when the interior temperature 

of PWM unit is over 120~150°C.

Communication function when failing: The 

fail signal is transmitted to the ECU when the 

PWM unit is malfunctioning.

Soft start function: The motor speed is 

gradually increased when the motor is 

initially operated.

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06-11

2112-01

5) Shutting-off Condition of the A/C Compressor

Coolant temperature

▶

When coolant temperature is below 20°C  or over 115°C, engine speed is below 650 rpm or 

over 4500 rpm for 4 seconds after engine starting, abrupt acceleration and A/C refrigerant 

pressure sensor detecting the followings

A/C compressor is turned off when the refrigerant pressure is below 2.0 kg/cm2 and then is 

turned on when the refrigerant pressure is over 2.4 kg/cm2.

A/C compressor is turned off when the refrigerant pressure is over 30 kg/cm2 and then is turned 

on when the refrigerant pressure is below 21.4 kg/cm2.

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07-3

1452-01

1. DIAGNOSTIC INFORMATION AND PROCEDURE

1) Ignition System