SsangYong Rexton. Service manual - part 433

M161 ENGINE CONTROLS  1F2-53

SSANGYONG  Y200

Mass Air Flow Sensor Input Voltage Inspection

1. Turn the ignition switch to “ON” position.

2. Measure the signal voltage between the ECM pin No. 103 and No. 104.

Notice: If the measured value is not within the specified value, the possible cause may be in cableor ECM
coupling.

Specified Value

4.7 ~ 5.2 V

Notice: If the measured value is not within the specified value, the possible cause may be in cableor ECM
coupling.

Mass Air Flow Sensor 12 volt Power Supply Inspection

1. Turn the ignition switch to “OFF” position.

2. Disconnect the HFM sensor connector.

3. Turn the ignition switch to “ON” position.

4. Measure the voltage between the ECM pin No. 105 and MAF sensor connecter terminal No. 2.

Ignition “ON”

Idling

Engine

Status

Specified Value

Application

0.9 ~ 1.1 V

1.3 ~ 1.7 V

(Coolant temperature is

over 70°C)

Notice: If the measured value is not within the specified value, the possible cause may be in cable or MAF
sensor in itself. Perform the 5 volt power supply inspection procedures.

Mass Air Flow Sensor 5 volt Power Supply Inspection

1. Turn the ignition switch to “OFF” position.

2. Disconnect the HFM sensor connector.

3. Turn the ignition switch to “ON” position.

4. Measure the voltage between the ECM pin No. 108 and MAF sensor connecter terminal No. 3.

Specified Value

4.7 ~ 5.2 V

5. Measure the voltage between the ECM pin No. 105 and MAF sensor connecter terminal No. 4.

Specified Value

11 ~ 14 V

Notice: If the measured value is not within the specified value, the possible cause may be in cable or Over
Voltage Protection Relay (OVPR).

SSANGYONG  Y200

1F2-54  M161 ENGINE CONTROLS

ENGINE COOLANT  TEMPERATURE (ECT) SENSOR

YAA1F590

Engine Coolant Temperature (ECT) sensor detects coolant temperature and supplies information to the ECM. It is
composed of metal housing with two NTC resistor, 4 pin connector. The ECM provides a 5 volt signal to the ECT
sensor through a dropping resistor. When the engine is cold, the ECT sensor provides high resistance, which the
ECM detects as a high signal voltage. As the engine warms up, the sensor resistance becomes lower, and the
signal voltage drops. At normal engine operating temperature, the ECT signal will measure about 1.5 to 2.0 volts.

The ECM uses information about coolant temperature to make the necessary calculations for:

•

Fuel delivery

•

Ignition control

•

Knock sensor system

•

Idle speed

•

Torque converter clutch application

•

Canister purge

•

Cooling fan operation

•

Others

1 Artificial Resin Housing
2 Metal Housing
3 NTC (Negative Temperature Coefficient)

Resistor

4 Connector
5 Engine Coolant Temperature Sensor

M161 ENGINE CONTROLS  1F2-55

SSANGYONG  Y200

YAD1F460

Temperature (°C)

-40

-30

-20

-10

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

Resistance (

Ω

Ω

Ω

Ω

Ω

)

48,550

27,000

15,570

9,450

5,890

3,790

2,500

1,692

1,170

826

594

434

322

243

185

143

111.6

88

71.2

Voltage (V)

4.90

4.82

4.70

4.52

4.43

3.96

3.57

3.14

2.70

2.26

1.86

1.51

1.22

0.98

0.78

0.63

0.50

0.40

0.33

SSANGYONG  Y200

1F2-56  M161 ENGINE CONTROLS

YAD1F470

Circuit Description

The ECT sensor uses a thermistor to control the signal voltage to the ECM. The ECM supplies a voltage on the
signal circuit to the sensor. When the engine coolant is cold, the resistance is high; therefore the ECT signal
voltage will be high

Engine Coolant Temperature Sensor Inspection

1. Turn the ignition switch to “ON” position.

2. Measure the voltage between the ECM pin No. 78 and No. 79.

Failure

Code

Description

Trouble  Area

Maintenance Hint

Engine coolant

temperature sensor low

voltage

Engine coolant

temperature sensor high

voltage

Engine coolant

temperature sensor

plausibility

Engine coolant

temperature insufficient

for closed loop fuel

control

ECT sensor short circuit to

ground or open

ECT sensor short circuit to

power

Malfunction in recognition of

ECT

When drop to about 50° C

below after warm up

Malfunction in recognition of

ECT

When minimum temperature

for lambda control after

warm up

•

Monitoring the actual coolant temperature

through scan t ool

•

Inspection the ECM pin 78, 79 about

short circuit or open with bad contact

•

Inspection the ECT sensor

•

Inspection the ECM

00

01

02

06

Temperature (°C)

20

80

100

Specified Value (V)

3.57

1.22

0.78