engine SSANGYONG KORANDO 1997 Service Repair Manual

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SYSTEM VOLTAGE
KAB1F190
Failure
CodeDescriptionTrouble AreaMaintenance Hint
08System voltage too low
Malfunction in recognition of
system source voltage.
Less than minimum 8 volts in
2,000 rpm below, or less than
10 volts in 2,000 rpm above.
DMonitoring the actual battery voltages
through the scan tool
DInspection the Engine Control Module
(ECM) pin 12, 11, 10, 5 about short
circuit or open with bad contact
DInspection the over voltage protection
relay
DInspection the battery
DInspection ECM

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IGNITION SWITCH
KAB1F200
Failure
CodeDescriptionTrouble AreaMaintenance Hint
71Starter signal
recognition failureWhen not detection of starter
signal
DInspection the Engine Control Module
(ECM) pin 2 circuit short or open with
bad contact
DInspection ECM

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FUEL SYSTEM
The function of the fuel metering system is to deliver the correct amount of fuel to the engine under all operating condi-
tions. The fuel is delivered to the engine by the individual fuel injectors mounted into the intake manifold near each
cylinder.
The main fuel control sensors are the Mass Air Flow (MAF) sensor and the oxygen (O2) sensors.
The MAF sensor monitors the mass flow of the air being drawn into the engine. An electrically heated element is
mounted in the intake air stream, where it is cooled by the flow of incoming air. Engine Control Module (ECM) modu-
lates 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
mass air flow. 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. 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.
The O2 sensors are located in the exhaust pipe before catalytic converter. The O2 sensors indicate to the ECM the
amount of oxygen in the exhaust gas, and the ECM changes the air/fuel ratio to the engine by controlling the fuel
injectors. The best air/fuel ratio to minimize exhaust emissions is 14.7 to 1, which allows the catalytic converter to
operate most efficiently. Because of the constant measuring and adjusting of the air/fuel ratio, the fuel injection system
is called a “closed loop” system.
The ECM uses voltage inputs from several sensors to determine how much fuel to provide to the engine. The fuel is
delivered under one of several conditions, called ‘‘modes”.
Starting Mode
When the ignition is turned ON, the ECM turns the fuel pump relay on for 1 second. The fuel pump then builds fuel
pressure. The ECM also checks the Engine Coolant Temperature (ECT) sensor and the Throttle Position (TP) sensor
and determines the proper air/fuel ratio for starting the engine. This ranges from 1.5 to 1 at -- 36°C(--33°F) coolant
temperature to 14.7 to 1 at 94°C (201°F) coolant temperature. The ECM controls the amount of fuel delivered in the
starting mode by changing how long the fuel injector is turned on and off. This is done by ‘‘pulsing” the fuel injectors for
very short times.
Run Mode
The run mode has two conditions called ‘‘open loop” and ‘‘closed loop”.
Open Loop
When the engine is first started and it is above 690 rpm, thesystem goes into “open loop” operation. In “open loop”, the
ECM ignores the signal from the HO2S and calculates the air/fuel ratio based on inputs from the ECT sensor and the
MAF sensor. The ECM stays in “open loop” until the following conditions are met:
DThe O2 has a varying voltage output, showing that it is hot enough to operate properly.
DThe ECT sensor is above a specified temperature (22.5°C).
DA specific amount of time has elapsed after starting the engine.
Closed Loop
The specific values for the above conditions vary with different engines and are stored in the Electronically Erasable
Programmable Read -- Only Memory (EEPROM). When these conditions are met, thesystem goes into “closed loop”
operation. In “closed loop”, the ECM calculates the air/fuel ratio (fuel injector on-- time) based on the signals from the
O2 sensors. This allows the air/fuel ratio to stay very close to 14.7 to 1.
Acceleration Mode
The ECM responds to rapid changes in throttle position and airflow and provides extra fuel.
Deceleration Mode
The ECM responds to changes in throttle position and airflow and reduces the amount of fuel. When deceleration is
very fast, the ECM can cut off fuel completely for short periods of time.

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Battery Voltage Correction Mode
When battery voltage is low, the ECM can compensate for a weak spark delivered by the ignition module by using the
following methods:
DIncreasing the fuel injector pulse width.
DIncreasing the idle speed rpm.
DIncreasing the ignition dwell time.
Fuel Cut- Off Mode
No fuel is delivered by the fuel injectors when the ignition is off. This prevents dieseling or engine run -- on. Also, the fuel
is not delivered if there are no reference pulses received from the CKP sensor. This prevents flooding.

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FUEL PUMP
YAA1F380
Requirements for Fuel Pump
ItemSpecified ValueItemSpecified Value
System Pressure3.8 barMinimum Delivery at 8V30 Litre/Hr
Maximum Pressure8.5 bar (12 V)Operating Voltage8V
Minimum Pressure5.0 bar (12 V)Maximum Allowable
Current7.5 A
Nominal Voltage12 VAmbient Temperature-- 30 ~ +70°C
Minimum Amount
of Fuel Supply114 Liter/Hr (12 V, 3.8 bar,
-- 30 ~ +70°C)Maximum Amount
of Fuel Supply165 Liter/Hr (12V, 3.8 bar,
-- 3 0 ~ + 7 0°C)

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KAB1F210
Failure
CodeDescriptionTrouble AreaMaintenance Hint
34Fuel pump relay short
circuit to batteryWhen short circuit to power
sourceDInspection the Engine Control Module
(ECM) pin 33 about short circuit or
openwithbadcontact
35Fuel pump relay short
circuit to ground or openWhen short circuit to ground
or open
openwithbadcontact
DInspection the fuel pump relay
DInspection the ECM
Circuit Description
When the ignition switch is turned ON, the ECM will activate the pump relay and run the in -- tank fuel pump. The fuel
pump willoperate as long as the engine is cranking or running and the ECM is receiving ignition reference pulses.
If there are no reference pulses, the ECM will shut off the fuel pump within 2 seconds after the ignition switch is turned
ON, engine stopped or engine stalled.
Fuel Pump Relay Inspection
Measure the voltage between the ECM terminal No. 33 and Ground.
Ignition Switch : ON
0v(for1~2sec.)
Cranking0v

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Measure the Fuel Delivery from the Fuel Pump
1. Disconnect the return pipe from fuel distributor and insert the appropriate hose into it.
2. Place the hose end into the beaker with the minimum capacity of 1 Liter
3. Turn the ignition switch to “ON” position.
4. Connect the terminal No. 33 and No. 5 of ECM with a service wire.
5. Measure the fuel delivery from the fuel pump
Specified Value
1 Liter/max. 35 sec.
Notice:Check the fuel filter and fuel line when the fuel delivery is not within specified value.
Measure the Current Consumption of Fuel Pump
1. Remove the fuel pump relay from fuse and relay box in trunk, and turn the ignition switch to “ON” position.
2. Using a multimeter, measure the current consumption by connecting the terminal No. 30 and No. 87 of the fuel
pump relay connector.
Specified Value
5~9A
Notice:Replace the fuel pump relay if the measured value is over 9 A.

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FUEL INJECTOR
YAA1F400
The Multipoint Fuel Injection (MFI) assembly is a solenoid -- operated device controlled by the Engine Control Module
(ECM) that meters pressurized fuel to an each individual cylinder. The injector sprays the fuel, in precise quantities at a
point in time determined by the ECM, directly toward the cylinder intake valve. ECM energizes the fuel injector solenoid
to lift the needle valve and to flow the fuel through the orifice. This injector ’s discharge orifice is calibrated to meet the
effective fuel atomization necessary for both ensuring the maximum homogeneity in the air -- fuel mixture and holding
the condensation along the walls of the intake tract to a minimum.
Fuel enters the top feed injector from above and flows through its vertical axis. The lower end extends into the intake
valve. Fuel from the tip is directed at the intake valve, causing it to become further atomized and vaporized before
entering the combustion chamber.
A fuel injector which is stuck partially open would cause a loss of fuel pressure after the engine is shut down. Also, an
extended crank time would be noticed on some engines. Dieseling could also occur because some fuel could be deliv-
ered to the engine after the ignition is turned off.