SsangYong Rexton. Service manual - part 432

SSANGYONG  Y200

1F2-48  M161 ENGINE CONTROLS

Failure

Code

Description

Trouble  Area

Maintenance Hint

Throttle position sensor

1 not plausible with

Throttle position sensor 2

High permanent throttle

signal

Mass air flow sensor

and throttle position

sensor failure

When difference between

TPS 1 and TPS 2

When failure of wiring

harness or actuator

When difference between

MAF and TPS signal

•

Monitoring the actual values through

scan tool

•

Inspection the ECM pin 84, 85, 87, 112,

67, 68 about short circuit or open with
bad contact

•

Inspection the throttle valve actuator

•

Inspection the ECM

126

127

185

Circuit Description

The ECM supplies a 5 volt reference signal and a ground to the TP sensor. The TP sensor sends a voltage signal
back to the ECM relative to the throttle plate opening. The volt age signal will vary from approximately 0.3 ~ 0.9
volts at closed throttle, to over 4.0 ~ 4.6 volts at Wide Open Throttle (WOT).

The TP sensors serve for engine load control according to the drive pedal command. Load adjustments independent
of the drive pedal command can be implemented; such functions are, for instance, idle control, speed control,
drive slip control, load shock damping, and similar functions .

When the actuator current fails , the throttle valve is returned to emergency operating position by a spring. The
throttle valve position, there by the actuator drive position check back is provided by two potentiometers. The
motor positions the throttle valve against the return spring force. Motor and return spring are two separate energy
sources . Each of them is able to position the throttle valve in emergency position alone. Throttle valve position
check back and monitoring is provided by two actual value potentiometers connected to the engine control
electronics.

Specified Value

<  10 

Ω

Throttle Actuator Inspection

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

2. Measure the TPS 1 signal volt age at the ECM pin No. 87 and TPS 2 signal volt age at the ECM pin No. 85.

TPS 1

TPS 2

Specified Value

Pedal Position

0.3 ~ 0.9 v

4.0 ~ 4.6 v

4.0 ~ 4.6 v

0.3 ~ 0.9 v

Closed

Opened

Closed

Opened

Throttle Actuator DC Motor Inspection

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

2. Measure the signal volt age between the ECM pin No. 67 and No. 68.

Throttle Actuator DC Motor Resistance

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

2. Measure the resistance between the ECM pin No. 67 and No. 68.

Ignition “ON”

Idling

Engine

Status

Specified Value

Application

0.8 ~ 2.3 v

1.0 ~ 2.5 v

(Coolant temperature is

over 70° C)

SSANGYONG  Y200

1F2-50  M161 ENGINE CONTROLS

HOT FILM AIR MASS (HFM) SENSOR

YAD1F430

The Hot Film Air Mass (HFM) sensor with recognition of flow direction related to pulsating flow is designed for
recording load on Engine Control Module (ECM) by measuring the output voltage proportional to the reference
voltage of the ECM.

Mass Air Flow Sensor

Mass Air Flow (MAF) is a thermal flow meter whose sensor element with its temperature sensors and heating area
is exposed to the MAF to be measured. A heating area located in the center of a thin membraneis controlled to an
over  temperature by a heating resistor and a temperature sensor of this membrane. And the value of over-
temperature depends on the temperature of the in-flowing air.

Two temperature sensors on upstream and downstream of the heating area show the same temperature without
incoming flow. With incoming flow, upstream part is cooled down but downstream temperature retains its temperature
more or less due to the air heated up in the heating area. This temperature difference in quantity and direction
depends on the direction of the incoming flow.

ECM modulates the flow of heating current to maintain the temperature differential between the heated film and
the intake air at a constant level. The amount of heating current required to maintain the temperature thus provides
an index for the MAF. This concept automatically compensates for variations in air density, as this is one of the
factors that determines the amount of warmth that the surrounding air absorbs from the heated element. MAF
sensor is located between the air filter and the throttle valve.

1 Housing
2 Protector Net
3 Electronic Housing

4 Connector
5 Hot Film Air Mass Sensor
6 Measuring Port

M161 ENGINE CONTROLS  1F2-51

SSANGYONG  Y200

Intake Air Temperature

The Intake Air Temperature (IAT) sensor is a part of Hot Film Air Mass (HFM) sensor and is a thermistor, a resistor
which changes value based on the temperature of theair entering the engine. Low temperature produces a high
resistance, while high temperature causes a low resistance as the following table.

The ECM provides 5 volts to the IAT sensor through a resistor in the ECM and measures the change in voltage to
determine the IAT. The voltage will be high when the manifold air is cold and low when the air is hot. The ECM
knows the intake IAT by measuring the voltage.

The IAT sensor is also used to control spark timing when the manifold air is cold.

Under high fuel demands, the MAF sensor reads a high mass flow condition, such as Wide Open Throttle (WOT).
The  ECM uses this information to enrich the mixture, thus increasing the fuel injector on-time, to provide the
correct amount of fuel. When decelerating, the mass flow decreases. This mass flow change is sensed by the
MAF sensor  and read by the ECM, which then decreases the fuel injector on-time due to the low fuel demand
conditions.

To facilitate the installation of the HFM in the intake passage, lubricating agents may be used. However, when
lubricants are used care must be taken to ensure that they do not enter the flow passage and cannot be sucked
in with the air flow.

The following tables show the relationship between MAF and output voltage.

Temp. (°C)

-40

-20

0

20

40

60

80

100

120

130

R min.(

Ω

Ω

Ω

Ω

Ω

)

35140

12660

5119

2290

1096

565

312

184

114

91

R nom. (

Ω

Ω

Ω

Ω

Ω

)

39260

13850

5499

2420

1166

609

340

202

127

102

R max. (

Ω

Ω

Ω

Ω

Ω

)

43760

15120

5829

2551

1238

654

370

222

141

114

Mass Air Flow (kg/h)

0

10

15

30

60

120

Voltage (V)

0.95 ~ 1.05

1.28

1.41

1.71

2.16

2.76

Mass Air Flow (kg/h)

250

370

480

640

800

Voltage (V)

3.51

3.93

4.23

4.56

4.82

SSANGYONG  Y200

1F2-52  M161 ENGINE CONTROLS

YAD1F440

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.

Failure

Code

Description

Trouble  Area

Maintenance Hint

Intake air temperature

sensor low voltage

Intake air temperature

sensor high voltage

Intake air temperature

sensor plausibility

Mass air flow sensor

plausibility

Mass air flow sensor

low voltage

Mass air flow sensor

high voltage

IAT sensor short circuit to

ground or open

IAT sensor short circuit to

power

Malfunction in recognition of

IAT

When functional problem

Malfunction in recognition of

MAF

When air mass not plausible

MAF sensor short circuit to

ground or open

MAF sensor short circuit to

power

•

Monitoring the actual air temperature

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 in

HFM sensor)

•

Inspection the ECM

03

04

05

09

10

11