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SsangYong Stavic / SsangYong Rodius (2005 year). Manual - part 51

1F-45

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

Circuit Description

The heated element on the MAF is a platinum film resistor (heater). It is located on a ceramic plate together with the other
elements in the bridge circuit. The temperature sensitive resistor (flow sensor) also included in the bridge. The separation
of heater and flow sensor facilitates design of the control circuitry. Saw cuts are employed to ensure thermal decoupling
between the heating element and the intake air temperature (IAT) sensor. The complete control circuitry is located on a
single layer. The voltage at the heater provides the index for the mass air flow. The MAF’s electronic circuitry then converts
the voltage to a level suitable for processing in the ECM. This device does not need a burn off process to maintain its
measuring precision over an extended period. In recognition of the fact that most deposits collect on the sensor element’s
leading edge, the essential thermal transfer elements are located downstream on the ceramic layer. The sensor element
is also design to ensure that deposits will not influence the flow pattern around the sensor.

The IAT sensor uses a thermistor to control the signal voltage to the ECM. The ECM supplies 5 volt reference and a
ground to the sensor. When the air is cold, the resistance is high; therefore the IAT signal voltage will be high. If the
intake air is warm, resistance is low; therefore the IAT signal voltage will be low.

Failur Code

Description

Trouble Area

Maintenance Hint

• Monitoring the actual air tempera-

ture through scan tool

• Inspection the ECM pin 80, 79

about short circuit or open with
bad contact

• Inspection the IAT sensor

(integrated in HFM sensor)

• Inspection the ECM

• Monitoring the actual air mass

flow through scan tool

• Inspection the ECM pin 81, 105

about short circuit or open with
bad contact

• Inspection the MAF sensor

(integrated 11 in HFM sensor)

• Inspection the ECM

Mass air flow sensor

high voltage

MAF sensor short circuit to

power

Mass air flow sensor

low voltage

MAF sensor short circuit to

ground or open

Mass air flow sensor

plausibility

Malfunction in recognition of

MAF

When air mass not plausible

Intake air temperature

sensor plausibility

Malfunction in recognition of IAT

When functional problem

Intake air temperature

sensor low voltage

IAT sensor short circuit to

ground or open

Intake air temperature

sensor high voltage

IAT sensor short circuit to power

1F-46

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

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.

Mass Air Flow Sensor Input Voltage Inspection

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

2. Measure the signal voltage between the ECM pin

Notice

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

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

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.

Notice

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

Ignition “ON”

Idling

Engine

status

Specified Value

0.9 ~ 1.1 v

1.3 ~ 1.7 v

(Coolant tempera-

ture is over 70 °C)

Application

Specified value

4.7 ~ 5.2 V

Specified value

4.7 ~ 5.2 V

Specified value

11 ~ 14 V

1F-47

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

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 Tcemperature Coefficient) resistor

4. Connector

5. Engine coolant temperature sensor

1F-48

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

-40

-30

-20

-10

100

110

120

130

140

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

71.2

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

Temperature (°C)

Resistance (

Ω)

Voltage (V)

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