Page 482 of 2053
1F2 -- 64 M161 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
Page 486 of 2053

1F2 -- 68 M161 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.
Page 498 of 2053

1F2 -- 80 M161 ENGINE CONTROLS
D AEW OO M Y_2000
OXYGEN SENSOR
YAA1F650
The oxygen sensor is unique among the engine control sensors because is acts like a battery and is able to generate
its own low voltage signal. It is located the exhaust system and monitors the amount of oxygen in the exhaust stream
and provides feedback to the Engine Control Module (ECM).
The electrically heated oxygen sensor warms up quickly and remains hot, even at idle when the exhaust manifold may
cool down.
The ECM applies a reference voltage of 450 mv to the
oxygen sensor, the ECM compares this reference volt-
age with the voltage generated by oxygen sensor. The
amount of voltage the oxygen sensor generates is pro-
portionate to the difference between the amount of oxy-
gen in the outside air and the exhaust gases. The
atmosphere contains about 21% oxygen. The exhaust
from a rich air/fuel ratio contains almost no oxygen. With
a large difference between the amounts of oxygen con-
taining the two surface, the sensor generates less volt-
age. When the exhaust gas is rich (below 14.7:1), the
voltage output is high, above 450 mv. When the exhaust
gas is lean (above 14.7:1 air/fuel ratio), the sensor ’s
voltage output is low, below 450 mv.
The ECM uses oxygen sensor information for:
DOpen loop / closed loop criteria
DIdeal air / fuel ratio
YAA1F660
Page 501 of 2053

M161 ENGINE CONTROLS 1F2 -- 83
D AEW OO M Y_2000
Failure
CodeDescriptionTrouble AreaMaintenance Hint
81
Bank 1 system short
term fuel trim adaptation
below lean threshold
When recognition the value
less than nominal control
threshold, it means that when
big deviation in control range
of adaptation values through
fuel and air mixture formation
93
Bank 1 system short
term fuel trim adaptation
above rich threshold
When recognition the value
more than nominal control
threshold, it means that when
big deviation in control range
of adaptation values through
fuel and air mixture formation
96
Bank 1 system short
term fuel trim at rich
stopWhen recognition the short
term fuel trim that more than
nominal threshold
97
Bank1 system short
term fuel trim at lean
stopWhen recognition the short
term fuel trim that less than
nominal threshold
DInspection the intake air leakage
DIns
pection the injectionquantities with
98
Bank 1 system idle
adaptation failure (above
rich threshold)When recognition the long
term fuel trim exceeds rich
threshold
DInspectiontheinjectionquantitieswith
injector block or leakage
DInspection the exhaust leakage
DInspection the ECM
99
Bank 1 system idle
adaptation failure (below
rich threshold)When recognition the long
term fuel trim exceeds lean
threshold
p
100
Bank 1 system learning
control failure (rich, low
load)When recognition the long
term fuel trim exceeds rich
threshold
101
Bank 1 system learning
control failure (lean, low
load)When recognition the long
term fuel trim exceeds lean
threshold
102
Bank 1 system learning
control failure (rich, high
load)When recognition the long
term fuel trim exceeds rich
threshold
103
Bank 1 system learning
control failure (rich, low
load)When recognition the long
term fuel trim exceeds lean
threshold
Circuit Description
In order to control emissions, a catalytic converter is used to covert harmful emissions into harmless water vapor and
carbon dioxide. The ECM has the ability to monitor this process by using a oxygen sensor. The oxygen sensor pro-
duces and output signal which indicates the storage capacity of the catalyst. This in turn indicates the catalyst’s ability
to convert exhaust emission effectively. If the oxygen sensor pigtail wiring, connector, or terminal is damaged. Do not
attempt to repair the wiring, connector, or terminals. In order for the sensor to function properly, it must have a clean air
reference provided to it. This clean air reference is obtained by way of the oxygen sensor wire(s). Any attempt to repair
the wires, connector, or terminal and degrade the oxygen sensor performance.
Page 502 of 2053

1F2 -- 84 M161 ENGINE CONTROLS
D AEW OO M Y_2000
Oxygen Sensor Signal Voltage Inspection
1. Maintain the engine speed is at idle while the coolant temperature is over 80°C.
2. Measure the oxygen sensor signal voltage between the ECM terminal No. 16 and No. 17.
Specified Value
-- 0.2 ~ 1.0 v
Notice:If the measured value is not within the specified value, the possible cause may be in cable, oxygen sensor or
ECM
Oxygen Sensor Heating Voltage Inspection
1. Maintain the engine speed is at idle while the coolant temperature is over 80°C.
2. Measure the oxygen sensor signal voltage between the ECM terminal No. 11 and No. 9.
Specified Value
11 ~ 14 v
Notice:If the measured value is not within the specified value, the possible cause may be in cable, oxygen sensor or
ECM
Oxygen sensor Heating Current Consumption Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the oxygen sensor heating current consumption between the ECM terminal No. 9 and No. 5.
Specified Value
0.2~2.0A
Notice:If the measured value is not within the specified value, the possible cause may be in cable, oxygen sensor or
ECM
Page 511 of 2053
M161 ENGINE CONTROLS 1F2 -- 93
D AEW OO M Y_2000
Failure
CodeDescriptionTrouble AreaMaintenance Hint
239
Unusual accelerator
pedal position sensor
comparison fault
(CPU 2)
240
Throttle potentiometer
comparison fault
(CPU 2)
241Unusual CPU
communication (CPU 2)
242Unusual CPU
configuration (CPU 2)
243A/D converter failure
(CPU 2)
244
Accelerator pedal
position sensor setpoint
fault between CPU 1
and CPU 2
System internal failureDInspection the Engine Control Module
(ECM)
245
Position controller
setpoint fault between
CPU 1 and CPU 2
y(ECM)
246
MSR setpoint fault
between CPU 1 and
CPU 2
247
Idle control setpoint fault
between CPU 1 and
CPU 2
248A/D converter overflow
(CPU 2)
249ROM fault (CPU 2)
250RAM fault (CPU 2)
251Cycle monitor fault
(CPU 2)
Page 532 of 2053

M161 ENGINE INTAKE & EXHAUST 1G2 -- 9
D AEW OO M Y_2000
Removal & Installation Procedure
1. Disconnect the battery ground cable.
2. Remove idle speed control plug connector (arrow).
3. Disconnect the brake booster vacuum line and other
vacuum lines.
4. Disconnect the rod from bearing bracket assembly
and remove the connection piece (8).
Installation Notice
Tightening Torque
36 -- 44 NSm (27 -- 33 lb-ft)
5. Unscrew the three bolts (4) and remove the idle regu-
lator and intermediate flange (6).
Installation Notice
Tightening Torque
22.5 -- 27.5 NSm
(16.6 -- 20.3 lb-ft)
6. Unscrew the two bolts (M8 X 16) and remove the sup-
port assembly.
Installation Notice
Tightening Torque
22.5 -- 27.5 NSm
(16.6 -- 20.3 lb-ft)
7. Unscrew the intake manifold mounting bolts (1) and
remove the intake manifold and gasket.
Installation Notice
Tightening Torque
22.5 -- 27.5 NSm
(16.6 -- 20.3 lb-ft)
Notice:Replace the gasket with new one.
8. Installation should follow the removal procedure in
the reverse order.
9. Start the engine and check for leaks in each connec-
tion.
Page 763 of 2053

D AEW OO M Y_2000
SECTION 1F3
OM600 ENGINE CONTROLS
Caution: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless other -
wise noted.
TABLE OF CONTENTS
Specifications 1F3 -- 1............................
Fastener Tightening Specifications 1F3 -- 1..........
Maintenance and Repair 1F3 -- 2...................
On -- Vehicle Service 1F3 -- 2.........................
Fuel System 1F3 -- 2.............................
Fuel Injection Pump Coding 1F3 -- 3................
Fuel Tank 1F3 -- 4...............................
Vacuum Control System Test 1F3 -- 5..............
Vacuum Pump Test 1F3 -- 10......................
Vacuum Pump 1F3 -- 12..........................
Vacuum Unit Replacement 1F3 -- 14...............
Idle Speed Adjustment 1F3 -- 15...................Fuel Pump Test 1F3 -- 17.........................
Fuel Pump 1F3 -- 20.............................
Injection Nozzle Test 1F3-- 21.....................
Injection Nozzles 1F3-- 24........................
Injection Nozzle Repair 1F3 -- 26...................
Removal and Installation of
Injection Timing Device 1F3 -- 29.................
Injection Timing Device 1F3 -- 34...................
StartofDeliveryTest
(Position Sensor, RIV Method) 1F3 -- 36..........
Fuel Injection Pump 1F3 -- 45.....................
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
ApplicationN∙mLb-- FtLb-In
Fuel Tank Mounting Nut28 -- 4721 -- 35--
Fuel Pump Pressure Line1310--
Fuel Injection Nozzle35 -- 4026 -- 30--
Fuel Injection Pipe1813--
Nozzle Tensioning Nut8059--
Screw Plug3022--
Left -- Hand Thread Bolt4634--