M162 ENGINE CONTROLS 1F1 -- 31
D AEW OO M Y_2000
KAB1F160
Failure
CodeDescriptionTrouble AreaMaintenance Hint
226Camshaft actuator short
circuit to battery
When malfunction of cam
DMonitoring the actual operational
status through scan tool
DInspection the ECM pin 73 about short
circuit or open
227Camshaft actuator short
circuit to ground or open
Whenmalfunctionofcam
phasing control
p
DInspection the power source short
circuit or open to cam actuator
DInspection the magnet and hardware
DInspection the ECM
Camshaft Actuator Current Consumption Inspection
1. Run the engine to reach the coolant temperature above 70°C.
2. Increase the engine rpm up to 2000 rpm
3. Measure the current between the No. 1 and No. 2 pin of the camshaft actuator connector.
Specified Value
1~1.5A
Notice:If the measured value is not within the specified value, check the cable.
1F1 -- 40 M162 ENGINE CONTROLS
D AEW OO M Y_2000
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.
1F1 -- 50 M162 ENGINE CONTROLS
D AEW OO M Y_2000
PURGE CONTROL VALVE
YAA1F440
The fuel vaporization control system is installed to inhibit the fuel vaporized gas from discharging into the atmosphere.
The fuel vaporized gas that is accumulated in the canister abstracts through the purge control valve purification during
the engine combustion (except the decreasing mode) and coolant temperature of over 80°C. For this reason, the En-
gine Control Module (ECM) transacts the engine speed, air inflow quantity, coolant temperature, and intake tempera-
ture.
The purge control valve is activated by the ECM frequency according with the engine rotating speed to adjust the
purification rate. The purification rate is determined by the continuous valve opening interval.
The purge control valve is activated by the ECM for the following conditions:
DCoolant temperature of over 80°C
DEngine speed of over 1,000 rpm
D2 minutes after starting
DWhen the fuel cut -- off mode is not activated
1F1 -- 56 M162 ENGINE CONTROLS
D AEW OO M Y_2000
INDUCTION SYSTEM
THROTTLE VALVE ACTUATOR
YAA1F540
The throttle actuator is actuated by the Engine Control Module (ECM) according to the position of the accelerator pedal
position.
It has two potentiometers which signal the position of the throttle valve to the ECM to enable it to recognize the various
engine load states.
Ignition “Off”
In the de-- energized states the throttle valve position is determined to be spring capsule.
Ignition “On”
When the ignition S/W on the servo motor in the throttle actuator is operated by the ECM. The throttle valve adopts a
position in line with the coolant temperature.
Closed position
In the closed throttle position, the servo motor controls engine speed by operating the throttle valve further (greater
mixture) or closing it further (reduced mixture), depending on coolant temperature and engine load. When this is done,
the throttle valve can be closed further by the servo motor overcoming the force of the spring capsule (mechanical end
stop). If the actuator is de-- energized, the throttle valve is resting against the spring capsule.
Consequently, the throttle valve opening is a constant 10-- 12°approximately.
At no load, this produces an engine speed of about 1,800 rpm
Driving
When driving (part/full throttle), the servo motor controls the throttle valve in line with the various load states and ac-
cording to the input signals from the pedal value sensor according to the input signals from the pedal value sensor
according to the position of the accelerator pedal.
The function of the EA (electronic accelerator) in the ECM determines the opening angle of the throttle valve through
the throttle actuator. Further functions are;
DIdle speed control
DCruise control
DReducing engine torque for ASR/ABS operation
DElectronic accelerator emergency running
DStoring faults
DData transfer through CAN
1F1 -- 58 M162 ENGINE CONTROLS
D AEW OO M Y_2000
Failure
CodeDescriptionTrouble AreaMaintenance Hint
126
Throttle position sensor
1 not plausible with
Throttle position sensor
2
When difference between
TPS 1 and TPS 2DMonitoring the actual values through
scan tool
DIns
pection the ECMpin 84, 85, 87,
127High permanent throttle
signalWhen failure of wiring
harness or actuator
DInspectiontheECMpin84,85,87,
112, 67, 68 about short circuit or open
with bad contact
Itiththttlltt
185
Mass air flow sensor
and throttle position
sensor failureWhen difference between
MAF and TPS signal
DInspection the throttle valve actuator
DInspection the ECM
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 voltage signalwill 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, thereby the actuator drive position checkback 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 checkback and monitor-
ing is provided by two actual value potentiometers connected to the engine control electronics.
Throttle Actuator Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the TPS 1 signal voltage at the ECM pin No. 87 and TPS 2 signal voltage at the ECM pin No. 85.
Pedal PositionSpecified Value
TPS1Closed0.3 ~ 0.9 vTPS1Opened4.0 ~ 4.6 v
TPS2Closed4.0 ~ 4.6 vTPS2Opened0.3 ~ 0.9 v
Throttle Actuator DC Motor Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 67 and No. 68.
Application
Specified Value
Ignition “ON”0.8 ~ 2.3 v
Engine StatusIdling1.0 ~ 2.5 v
(Coolant temperature is over 70°C)
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.
Specified Value
<10Ω
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