sensor SSANGYONG KORANDO 1997 Service Owner's Guide

1F1 -- 60 M162 ENGINE CONTROLS
D AEW OO M Y_2000
HOT FILM AIR MASS (HFM) SENSOR
YAA1F570
The Hot Film Air Mass (HFM) sensor with recognition of flow direction related to pulsating flow is designed for record-
ing 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 membrane is 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 in-
coming 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.
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 lubri-
cants 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.

M162 ENGINE CONTROLS 1F1 -- 61
D AEW OO M Y_2000
The following tables show the relationship between MAF and output voltage.
Mass Air Flow (kg/h)
Voltage (v)Mass Air Flow (kg/h)Voltage (v)
00.95 ~ 1.052503.51
101.283703.93
151.414804.23
301.716404.56
602.168004.82
1202.76
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 the air entering the engine. Low temperature produces a high resist-
ance, 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.
Te m p. (°C)
Rmin.(Ω)R nom. (Ω)R max. (Ω)
-- 4 0351403926043760
-- 2 0126601385015120
0511954995829
20229024202551
40109611661238
60565609654
80312340370
100184202222
120114127141
13091102114

1F1 -- 62 M162 ENGINE CONTROLS
D AEW OO M Y_2000
KAB1F250
Failure
CodeDescriptionTrouble AreaMaintenance Hint
03Intake air temperature
sensor low voltageIAT sensor short circuit to
ground or openDMonitoring the actual air temperature
throu
gh scan tool
04Intake air temperature
sensor high voltageIAT sensor short circuit to
power
throughscantool
DInspection the ECM pin 80, 79 about
short circuit or open with bad contact
05Intake air temperature
sensor plausibilityMalfunction in recognition of
IAT
When functional problem
p
DInspection the IAT sensor (integrated
in HFM sensor)
DInspection the ECM
09Mass air flow sensor
plausibilityMalfunction in recognition of
MAF
When air mass not plausibleDMonitoring the actual air mass flow
through scan tool
DIns
pection the ECMpin 81, 105 about
10Mass air flow sensor low
voltageMAF sensor short circuit to
ground or open
DInspectiontheECMpin81,105about
short circuit or open with bad contact
DInspection the MAF sensor (integrated
iHFM)
11Mass air flow sensor
high voltageMAF sensor short circuit to
powerin HFM sensor)
DInspection the ECM
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 depositswill 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 voltagewill be high. If the
intake air is warm, resistance is low; therefore the IAT signal voltagewill be low.

M162 ENGINE CONTROLS 1F1 -- 63
D AEW OO M Y_2000
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.
Application
Specified Value
Ignition “ON”0.9 ~ 1.1 v
Engine StatusIdling1.3 ~ 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
4.7~5.2v
Notice:If the measured value is not within the specified value, the possible cause may be in cable or ECM coupling.
5. Measure the voltage between the ECM pin No. 105 and MAF sensor connecter terminal No. 4.
Specified Value
4.7~5.2v
Notice:If the measured value is not within the specified value, the possible cause may be in cable or 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.
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).

1F1 -- 64 M162 ENGINE CONTROLS
D AEW OO M Y_2000
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 signalwill measure about 1.5 to 2.0 volts.
The ECM uses information about coolant temperature to make the necessary calculations for:
DFuel delivery
DIgnition control
DKnock sensor system
DIdle speed
DTorque converter clutch application
DCanister purge
DCooling fan operation
DOthers

1F1 -- 66 M162 ENGINE CONTROLS
D AEW OO M Y_2000
KAB1F260
Failure
CodeDescriptionTrouble AreaMaintenance Hint
00
Engine coolant
temperature sensor low
voltageECT sensor short circuit to
ground or open
01
Engine coolant
temperature sensor high
voltageECT sensor short circuit to
power
DMonitoring the actual coolant
temperaturethroughscantool
02
Engine coolant
temperature sensor
plausibilityMalfunction in recognition of
ECT
When drop to about 50°C
below after warm uptemperaturethroughscantool
DInspection the ECM pin 78, 79 about
short circuit or open with bad contact
DInspection the ECT sensor
DIns
pection the ECM
06
Engine coolant
temperature insufficient
for closed loop fuel
controlMalfunction in recognition of
ECT
When minimum temperature
for lambda control after warm
up
DInspectiontheECM
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 voltagewill 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.
Temperature (°C)
Specified Value (V)
203.57
801.22
1000.78

M162 ENGINE CONTROLS 1F1 -- 67
D AEW OO M Y_2000
3. Turn the ignition switch to “OFF” position.
4. Disconnect the ECT sensor connector.
5. Turn the ignition switch to “ON” position.
6. Measure the resistance between the ECT sensor terminal pin No. 1 and No. 4.
Temperature (°C)
Specified Value (Ω)
202,500
80322
100185
Notice:Replace wiring and coolant temperature sensor if out of specified value.

1F1 -- 68 M162 ENGINE CONTROLS
D AEW OO M Y_2000
ACCELERATOR PEDAL MODULE
YAA1F620
The Acceleration Pedal Position (APP) sensor is mounted on the accelerator pedal assembly. The sensor is actually
two individual APP sensors and one housing. This sensor works with the Throttle Position (TP) sensor to provide input
to the Engine Control Module (ECM) regarding driver requested accelerator pedal and throttle angle at the throttle
body.
When the APP sensor is defected:
When the APP 1 or APP 2 sensor is defected condition, the engine is still running at idle condition but, the accelerator
pedal reaction is not response correctly and also, the engine rpmwill be reacted to 4,000 rpm slowly. If the APP 1
sensor is out of order, the APP 2 sensor will be conducted with signal as a default signal but, the throttle valve opening
is limited 60% and delayed opening speed.
When the TP sensor or servo motor is defected:
When the TP 1, 2 sensor or servo motor is defected condition, the throttle valvewill be closed to the spring capsule by
spring force, at this condition, the throttle valvewillopen 10°~20°and engine rpmwill be controlled by ECM will
opening (On/Off) time of injector. Theengine rpmwill be maintaining 900 rpm (at idle) to 1,800 according to theengine
load.

M162 ENGINE CONTROLS 1F1 -- 69
D AEW OO M Y_2000
KAB1F270
Failure
CodeDescriptionTrouble AreaMaintenance Hint
122
Acceleration pedal
position sensor signal
failureWhen malfunction of APP
Sensor
160
Acceleration pedal
position 1 sensor low
voltageAPP 1 sensor short circuit to
ground or open
161
Acceleration pedal
position sensor 1 high
voltageAPP 1 sensor short circuit to
power
DMonitoring the actual values through
162
Acceleration pedal
position sensor 2 low
voltageAPP 2 sensor short circuit to
ground or open
Monitoringtheactualvaluesthrough
scan tool
DInspection the ECM pin 31, 47, 32, 48,
59, 51 about short circuit or open with
badcontact
163
Acceleration pedal
position sensor 2 high
voltageAPP 2 sensor short circuit to
power
badcontact
DInspection the APP sensor
DInspection the ECM
164
Accelerator pedal
position sensor 1 not
plausible with
accelerator pedal
position sensor 2
When difference between
APP 1 sensor and APP 2
sensor
167
Both setpoint
Accelerator pedal
position sensor defectiveWhen defective of both APP
sensor
Circuit Description
The ECM supplies a 5 or 2.5 volt reference signal and a ground to the APP sensor 1 or 2. The ECM calculates on these
signal lines. The APP sensor output changes as the accelerator pedal is moved. The output of the APP 1 and APP 2
sensor are low, about 0.4 ~ 0.7 volts and 0.2 ~ 0.35 volts respectively at the closed throttle position. As pushing the
accelerator pedal, the output increases so that the output voltageswill be about 4.3 ~ 4.8 volts and 2.1 ~ 2.4 volts
individually when accelerating fully with the kick down, at Wide Open Throttle (WOT).

1F1 -- 70 M162 ENGINE CONTROLS
D AEW OO M Y_2000
Acceleration Pedal Position Sensor 1 Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 47 and No. 31 while operating the accelerator pedal as follow-
ing conditions.
DNot depress the pedal (closed throttle position)
DFully depress the pedal (full throttle with kick down)
Condition of Throttle Valve
Specified Value (V)
Closed Throttle Valve0.3 ~ 0.7
Fully Depressed Throttle Valve4.3 ~ 4.8
Notice:If measured value is not within the specified value, check the pedal valve sensor and the supply voltage to
APP 1 sensor.
Acceleration Pedal Position Sensor 2 Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 48 and No. 50 while operating the accelerator pedal as follow-
ing conditions.
DNot depress the pedal (closed throttle position)
DFully depress the pedal (full throttle with kick down)
Condition of Throttle Valve
Specified Value (V)
Closed Throttle Valve0.1 ~ 0.4
Fully Depressed Throttle Valve2.1 ~ 2.5
Notice:If measured value is not within the specified value, check the pedal valve sensor and the supply voltage to
APP sensor 2.