JLC294B
REMOVALNJLC00561. Remove the undercover, splash cover (right), and accessory
belt.
2. Drain engine coolant. Refer to LC-43, ªChanging Engine Cool-
antº.
3. Support the bottom of the oil pan with a floor jack etc., and
remove the right engine mount bracket (front side of the
engine).
4. Remove the water pump pulley.
+Loosen the pulley bolts after fixing the pulley using a screw-
driver etc.
5. Remove engine mount brackets.
6. Remove the water pump.
INSPECTIONNJLC0057+Check for rust and contamination adhering to the water pump
and vane.
+Turn the pump shaft by hand, and check that the pump turns
smoothly without looseness.
INSTALLATIONNJLC0058+Install the parts in the reverse order of removal.
+Install the water pump pulley with the front mark (painted white,
used to prevent errors during assembly) facing the front of the
engine. Refer to the figure above.
ENGINE COOLING SYSTEMYD
Water Pump (Cont'd)
LC-39
CLOSED THROTTLE POSITION SWITCH
(WHERE FITTED)........................................................426
Component Description ...........................................426
ECM Terminals and Reference Value .....................426
Wiring Diagram ........................................................427
Diagnostic Procedure ..............................................428
Component Inspection .............................................431
INTAKE VALVE TIMING CONTROL SOLENOID
VALVE..........................................................................432
Component Description ...........................................432
Operation .................................................................432
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................432
ECM Terminals and Reference Value .....................432
Wiring Diagram ........................................................433
Diagnostic Procedure ..............................................434
Component Inspection .............................................436
A/T COMMUNICATION LINE......................................437
System Description ..................................................437
Wiring Diagram ........................................................438
Diagnostic Procedure ..............................................439
PARK/NEUTRAL POSITION (PNP) SWITCH............441
Component Description ...........................................441
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................441
ECM Terminals and Reference Value .....................441
Wiring Diagram ........................................................442
Diagnostic Procedure ..............................................443
INJECTOR...................................................................446
Component Description ...........................................446
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................446
ECM Terminals and Reference Value .....................446
Wiring Diagram ........................................................447
Diagnostic Procedure ..............................................448
Component Inspection .............................................450
IGNITION SIGNAL.......................................................451
Component Description ...........................................451
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................451
ECM Terminals and Reference Value .....................451
Wiring Diagram ........................................................452
Diagnostic Procedure ..............................................454
Component Inspection .............................................458
START SIGNAL...........................................................460
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................460
ECM Terminals and Reference Value .....................460
Wiring Diagram ........................................................461
Diagnostic Procedure ..............................................462
FUEL PUMP.................................................................464
System Description ..................................................464Component Description ...........................................464
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................464
ECM Terminals and Reference Value .....................465
Wiring Diagram ........................................................466
Diagnostic Procedure ..............................................467
Component Inspection .............................................469
POWER STEERING OIL PRESSURE SWITCH.........470
Component Description ...........................................470
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................470
ECM Terminals and Reference Value .....................470
Wiring Diagram ........................................................471
Diagnostic Procedure ..............................................472
Component Inspection .............................................473
REFRIGERANT PRESSURE SENSOR......................475
Description ...............................................................475
ECM Terminals and Reference Value .....................475
Wiring Diagram ........................................................476
Diagnostic Procedure ..............................................477
ELECTRICAL LOAD SIGNAL.....................................480
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................480
ECM Terminals and Reference Value .....................480
Wiring Diagram ........................................................481
Diagnostic Procedure - Load Signal - .....................483
Diagnostic Procedure - Heater Control Panel
(Fan Switch) - ..........................................................487
MI & DATA LINK CONNECTORS..............................488
Wiring Diagram ........................................................488
SERVICE DATA AND SPECIFICATIONS (SDS).......489
Fuel Pressure Regulator..........................................489
Idle Speed and Ignition Timing ................................489
Mass Air Flow Sensor..............................................489
Intake Air Temperature Sensor ................................489
Engine Coolant Temperature Sensor ......................489
Throttle Position Sensor ..........................................489
Heated Oxygen Sensor 1 Heater (Front) ................489
Heated Oxygen Sensor 2 Heater (Rear).................489
EGR Volume Control Valve (Where Fitted) .............490
EGR Temperature Sensor (Where Fitted) ...............490
EVAP Canister Purge Volume Control Valve ..........490
IACV-AAC Valve ......................................................490
Injector .....................................................................490
Ignition Coil with Power Transistor ..........................490
Condenser ...............................................................490
Fuel Pump ...............................................................490
Crankshaft Position Sensor (POS) ..........................491
Camshaft Position Sensor (PHASE) .......................491
CONTENTS(Cont'd)
EC-6
SEF706Y
Engine Fuel & Emission Control System=NJEC0004+Always use a 12 volt battery as power source.
+Do not attempt to disconnect battery cables while engine
is running.
+Before connecting or disconnecting the ECM harness
connector, turn ignition switch OFF and disconnect nega-
tive battery terminal. Failure to do so may damage the
ECM because battery voltage is applied to ECM even if
ignition switch is turned off.
SEF707Y
+Do not disassemble ECM.
+If a battery terminal is disconnected, the memory will
return to the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is
disconnected. However, this is not an indication of a prob-
lem. Do not replace parts because of a slight variation.
SEF908W
+When connecting or disconnecting ECM harness
connector, use lever as shown.
When connecting, fasten connector securely with lever
moved until it stops.
SEF291H
+When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminals when connecting pin connectors.
+Securely connect ECM harness connectors.
A Poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.
+Keep ECM harness at least 10 cm (4 in) away from adja-
cent harness, to prevent an ECM system malfunctions due
to receiving external noise, degraded operation of ICs, etc.
+Keep ECM parts and harness dry.
PRECAUTIONSQG
Engine Fuel & Emission Control System
EC-17
System ChartNJEC0013
Input (Sensor) ECM Function Output (Actuator)
+Camshaft position sensor (PHASE)
+Crankshaft position sensor (POS)
+Mass air flow sensor
+Engine coolant temperature sensor
+Heated oxygen sensor 1 (front)
+Ignition switch
+Throttle position sensor
+PNP switch
+Air conditioner switch
+Knock sensor
+EGR temperature sensor*1, *4
+Battery voltage
+Power steering oil pressure switch
+Vehicle speed sensor
+Intake air temperature sensor
+Heated oxygen sensor 2 (rear)*2
+TCM (Transmission Control Module)*3
+Closed throttle position switch
+Electrical load
+Refrigerant pressure sensorFuel injection & mixture ratio control Injectors
Electronic ignition system Power transistor
Idle air control system IACV-AAC valve
Intake valve timing controlIntake valve timing control sole-
noid valve
Fuel pump control Fuel pump relay
On board diagnostic systemMalfunction indicator
(On the instrument panel)
EGR control*4 EGR volume control valve*4
Heated oxygen sensor 1/2 heater (front/
rear) controlHeated oxygen sensor 1/2 heater
(front/rear)
EVAP canister purge flow controlEVAP canister purge volume con-
trol solenoid valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
*1: These sensors are not used to control the engine system. They are used only for the on board diagnosis.
*2: Under normal conditions, this sensor is not for engine control operation.
*3: The DTC related to A/T will be sent to ECM.
*4: If so equipped
ENGINE AND EMISSION CONTROL OVERALL SYSTEMQG
System Chart
EC-28
Multiport Fuel Injection (MFI) System
DESCRIPTIONNJEC0014Input/Output Signal ChartNJEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
Fuel injec-
tion & mix-
ture ratio
controlInjector Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 (front) Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
PNP switch Gear position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Electrical load Electrical load signal
Battery Battery voltage
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2 (rear)* Density of oxygen in exhaust gas
* Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNJEC0014S02The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the camshaft position sensor and the mass air
flow sensor.
Various Fuel Injection Increase/Decrease CompensationNJEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.
+During warm-up
+When starting the engine
+During acceleration
+Hot-engine operation
+When selector lever is changed from ªNº to ªDº (A/T models)
+High-load, high-speed operation
+During deceleration
+During high engine speed operation
+During high vehicle speed operation (M/T models)
+Extremely high engine coolant temperature
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Multiport Fuel Injection (MFI) System
EC-29
System DescriptionNJEC0015S02
SEF742M
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of
the engine. The ignition timing data is stored in the ECM. This data forms the map shown above.
The ECM receives information such as the injection pulse width, crankshaft position sensor signal and cam-
shaft position sensor signal. Computing this information, ignition signals are transmitted to the power transis-
tor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
AÉBTDC
During the following conditions, the ignition timing is revised by the ECM according to the other data stored
in the ECM.
+At starting
+During warm-up
+At idle
+During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions.
If engine knocking occurs, the knock sensor monitors the condition. The signal is transmitted to the ECM. The
ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut Control
DESCRIPTIONNJEC0016Input/Output Signal ChartNJEC0016S01
Sensor Input Signal to ECMECM func-
tionActuator
Air conditioner switch Air conditioner ªONº signal
Air condi-
tioner cut
controlAir conditioner relay PNP switch Neutral position
Throttle position sensor Throttle valve opening angle
Crankshaft position sensor (POS) Engine speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
Vehicle speed sensor Vehicle speed
Power steering oil pressure switch Power steering operation
System DescriptionNJEC0016S02This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
+When the accelerator pedal is fully depressed.
+When cranking the engine.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Electronic Ignition (EI) System (Cont'd)
EC-32
If results are unsatisfactory, perform Fuel Pressure Regulator
Check, EC-39.
SEF718B
Fuel Pressure Regulator CheckNJEC00261. Stop engine and disconnect fuel pressure regulator vacuum
hose from intake manifold.
2. Plug intake manifold with a rubber cap.
3. Connect variable vacuum source to fuel pressure regulator.
4. Start engine and read indication of fuel pressure gauge as
vacuum is changed.
Fuel pressure should decrease as vacuum increases. If results
are unsatisfactory, replace fuel pressure regulator.
JEF088Y
SEF927W
Injector
REMOVAL AND INSTALLATIONNJEC00271. Release fuel pressure to zero.
2. Remove fuel tube assemblies in numerical sequence as
shown in the Figure at left.
3. Expand and remove clips securing fuel injectors.
4. Extract fuel injectors straight from fuel tubes.
+Be careful not to damage injector nozzles during removal.
+Do not bump or drop fuel injectors.
5. Install fuel injectors.
Carefully install O-rings, including the one used with the pres-
sure regulator.
+Lubricate O-rings with a smear of engine oil.
+Be careful not to damage O-rings with service tools or
finger nails or clips. Do not expand or twist O-rings.
+Discard old clips; replace with new ones.
6. Position clips in grooves on fuel injectors.
+Make sure that protrusions of fuel injectors are aligned
with cutouts of clips after installation.
BASIC SERVICE PROCEDUREQG
Fuel Pressure Regulator Check
EC-39
SEF933W
SEF284G
+Method B
a) Remove No. 1 ignition coil.
b) Connect No. 1 ignition coil and No. 1 spark plug with suitable
high-tension wire as shown, and attach timing light clamp to
this wire.
c) Check ignition timing.
SEF166Y
PreparationNJEC0592+Make sure that the following parts are in good order.
a)Battery
b)Ignition system
c)Engine oil and coolant levels
d)Fuses
e)ECM harness connector
f)Vacuum hoses
g)Air intake system
(Oil filler cap, oil level gauge, etc.)
BASIC SERVICE PROCEDUREQG
How to Check Idle Speed and Ignition Timing (Cont'd)
EC-42