
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 -- 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.

D AEW OO M Y_2000
SECTION 1B2
M161 ENGINE MECHANICAL
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 1B2 -- 2............................
Fastener Tightening Specifications 1B2 -- 2..........
Special Tools 1B2 -- 4.............................
Special Tools Table 1B2-- 4.......................
Maintenance and Repair 1B2 -- 7...................
On-- Vehicle Service 1B2-- 7.........................
Engine Assembly 1B2-- 7.........................
Crankcase Ventilation System 1B2-- 14.............
Generator 1B2-- 18..............................
Engine Mount 1B2-- 19...........................
Poly V-- Belt 1B2 -- 20.............................
Tensioning Device 1B2-- 22.......................
Tensioning Device Shock Absorber 1B2-- 23........
Poly V-- Belt Inspection 1B2-- 24...................
Cylinder Head Cover 1B2-- 26.....................
Cylinder Head Front Cover 1B2 -- 28...............
Cylinder Head 1B2-- 30...........................
Timing Gear Case Cover 1B2-- 34.................
Crankshaft Sealing Rear Cover 1B2-- 37...........
Belt Pulley and Vibration Damper 1B2-- 39..........
Crankshaft Front Radial Seal 1B2-- 42.............
Crankshaft Rear Radial Seal 1B2-- 44..............
Crankshaft 1B2-- 45.............................
Flywheel / Driven Plate 1B2 -- 51...................
Camshaft Adjuster 1B2-- 54.......................Camshaft Sprocket Bolt 1B2-- 57..................
Camshaft 1B2-- 58..............................
Camshaft Timing Position 1B2 -- 61................
Valve Spring 1B2 -- 63............................
Valve Stem Seal 1B2-- 67........................
Chain Tensioner 1B2-- 68.........................
Timing Chain 1B2-- 72............................
Tensioning Rail 1B2-- 77..........................
Cylinder Head Guide Rail 1B2-- 78.................
Crankcase Guide Rail 1B2-- 80....................
Crankshaft Sprocket 1B2-- 81.....................
Piston 1B2-- 83..................................
Connecting Rod 1B2-- 86.........................
Piston Ring 1B2 -- 88.............................
Oil Pan 1B2-- 90.................................
Engine Oil and Oil Filter Element 1B2-- 92..........
Oil Pump 1B2-- 95...............................
Oil Pressure Relief Valve 1B2-- 97.................
Oil Non-Return Valve 1B2-- 98....................
Oil Dipstick Guide Tube 1B2-- 99..................
Unit Repair 1B2 -- 100............................
Core Plugs in Crankcase 1B2-- 100................
Cylinder Bore 1B2-- 102..........................
Crankcase Mating Surface 1B2-- 104..............
Cylinder Head Mating Surface 1B2-- 106...........

D AEW OO M Y_2000
SECTION 1F2
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
Engine and ECM Problem Check Report 1F2 -- 2....
Specifications 1F2 -- 3............................
Engine Data Display Table 1F2 -- 3.................
Fastener Tightening Specifications 1F2 -- 4..........
Fuel System Specification 1F2 -- 5.................
Temperature vs Resistance 1F2 -- 5................
Special Tools and Equipment 1F2 -- 6..............
Special Tools Table 1F2 -- 6.......................
Schematic and Routing Diagrams 1F2 -- 7..........
ECM Wiring Diagram
(2.3L DOHC -- MSE 3.53S) 1F2 -- 7..............
Diagnosis 1F2 -- 14................................
Failure Code Diagnosis 1F2 -- 14.....................
Clearing Failure Codes 1F2 -- 14...................
Failure Codes Table 1F2 -- 14.....................
Ignition System 1F2 -- 18...........................
Ignition Coil 1F2 -- 20.............................
Crankshaft Position (CKP) Sensor 1F2 -- 22.........
Camshaft Position (CMP) Sensor 1F2 -- 26..........
Camshaft Actuator 1F2 -- 30......................
Knock Sensor (KS) 1F2 -- 32......................
Spark Plug 1F2 -- 34.............................
System Voltage 1F2 -- 38.........................
Ignition Switch 1F2 -- 39..........................
Fuel System 1F2 -- 40..............................
Fuel Pump 1F2 -- 42.............................
Fuel Injector 1F2 -- 46............................
Purge Control Valve 1F2 -- 50.....................
Fuel Rail 1F2 -- 52...............................
Fuel Pressure Regulator 1F2 -- 54.................
Induction System 1F2 -- 56..........................
Throttle Valve Actuator 1F2 -- 56...................
Hot Film Air Mass (HFM) Sensor 1F2 -- 60..........
Engine Coolant Temperature (ECT) Sensor 1F2 -- 64.
Accelerator Pedal Module 1F2 -- 68................Cooling Fan 1F2 -- 72............................
A/C Compressor Relay 1F2 -- 73...................
Cruise Control Switch 1F2 -- 74....................
Traction Control System (TCS) 1F2 -- 75............
Stop Lamp Switch 1F2 -- 76.......................
Engine RPM 1F2 -- 77............................
Exhaust System 1F2 -- 78...........................
Catalytic Converter 1F2 -- 78......................
Oxygen Sensor 1F2 -- 80.........................
Engine Control Module 1F2 -- 86.....................
Serial Data Communication 1F2--88...............
Internal Failure 1F2 -- 90..........................
Electronic Throttle Controller Safety
Malfunction 1F2 -- 92...........................
Immobilizer 1F2 -- 94.............................
Maintenance and Repair 1F2 -- 95..................
On -- Vehicle Service 1F2 -- 95........................
Discharging the Pressure in Fuel System 1F2 -- 95...
Fuel Pump 1F2 -- 95.............................
Fuel Filter 1F2 -- 96..............................
Fuel Tank 1F2 -- 97..............................
Fuel Pressure Regulator 1F2 -- 98.................
Fuel Rail and Injector 1F2 -- 99....................
Engine Coolant Temperature Sensor 1F2 -- 100......
Throttle Body (Integrated with the
Actuator) 1F2 -- 101............................
Hot Film Air Mass (HFM) Sensor 1F2 -- 102.........
Knock Sensor 1F2 -- 102..........................
Pedal Position Sensor 1F2 -- 103...................
Oxygen Sensor 1F2 -- 103........................
Purge Control Valve 1F2 -- 104....................
Canister 1F2 -- 104...............................
Camshaft Position Sensor 1F2 -- 104...............
Crankshaft Position Sensor 1F2 -- 105..............
Engine Control Module 1F2 -- 105..................

1F2 -- 40 M161 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.

1F2 -- 60 M161 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.

D AEW OO M Y_2000
SECTION 1B3
OM600 ENGINE MECHANICAL
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
otherwise noted.
TABLE OF CONTENTS
Specifications 1B3 -- 2............................
Fastener Tightening Specifications 1B3 -- 2..........
Special Tools 1B3 -- 4.............................
Special Tools Table 1B3-- 4.......................
Maintenance and Repair 1B3 -- 12..................
On-- Vehicle Service 1B3-- 12........................
Engine Assembly 1B3-- 12........................
Poly V-- Belt 1B3 -- 21.............................
Tensioning Device 1B3-- 23.......................
Poly V-- Belt Alignment & Inspection 1B3-- 26........
Prechamber 1B3-- 29............................
Milling of Prechamber Sealing Surface 1B3 -- 32.....
TDC (TDC Sensor Bracket) Setting 1B3 -- 35........
Cylinder Head 1B3-- 37...........................
Timing Case Cover 1B3 -- 63......................
Crankshaft End Cover 1B3-- 71...................
Vibration Damper and Hub 1B3-- 74...............
Crankshaft Front Radial Seal 1B3-- 80.............
Crankshaft Ball Bearing 1B3-- 82..................
Crankshaft 1B3-- 83.............................
Flywheel 1B3 -- 93...............................
Machining of Flywheel 1B3-- 97...................
Flywheel Ring Gear 1B3 -- 98......................
Hydraulic Valve Clearance Compensation
Element Check 1B3-- 101.........................
Valve Tappets 1B3-- 103..........................
Valve Spring Check 1B3-- 105.....................Valve Springs (Cylinder Head Removed) 1B3-- 106..
Valve Springs (Cylinder Head Installed) 1B3-- 109...
Valve Stem Seals 1B3-- 112......................
Check and Replacement of Valve Guides 1B3-- 116..
Valve Seat Rings 1B3-- 122.......................
Check and Machining of Valves 1B3-- 127..........
Machining of Valve Seat 1B3-- 132.................
Camshaft Timing Test 1B3-- 137...................
Camshaft 1B3-- 139.............................
Chain Tensioner 1B3-- 145........................
Timing Chain 1B3-- 147...........................
Tensioning Rail 1B3-- 151.........................
Cylinder Head Guide Rail 1B3-- 152................
Timing Case Cover Guide Rail 1B3-- 156...........
Crankshaft Sprocket 1B3-- 158....................
Piston 1B3-- 163.................................
Oil Filter 1B3-- 169...............................
Oil Pan 1B3-- 171................................
Oil Spray Nozzle 1B3-- 174.......................
Oil Pump 1B3-- 175..............................
Unit Repair 1B3 -- 177............................
Cylinder Head Pressure Leakage Test 1B3-- 177....
Facing Cylinder Head Mating Surface 1B3 -- 178.....
Replacement of Crankcase Core Plug 1B3-- 180.....
Facing Crankcase Contacting Surface 1B3 -- 182....
Oil Gallery Steel Ball 1B3-- 183....................
Cylinder Bore Measurement 1B3-- 187.............

1F3 -- 2 OM600 ENGINE CONTROLS
D AEW OO M Y_2000
MAINTENANCE AND REPAIR
ON -- VEHICLE SERVICE
FUEL SYSTEM
1 Fuel Injection Pump
2 Fuel Feed Pump
3 Overflow Valve
4 Injection Nozzle
5 Pre -- filter6 Fuel Retrun Hose
7 Injection Line
8 Fuel Tank
9 Fuel Filter
10 Choke Orifice