Diagnostic Procedure ..............................................487
Component Inspection .............................................490
EGR VOLUME CONTROL SYSTEM (WHERE
FITTED)........................................................................491
Description ...............................................................491
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................492
ECM Terminals and Reference Value .....................493
Wiring Diagram ........................................................494
Diagnostic Procedure ..............................................496
Component Inspection .............................................501
EVAP CANISTER PURGE VOLUME CONTROL
SOLENOID VALVE......................................................503
Description ...............................................................503
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................503
ECM Terminals and Reference Value .....................504
Wiring Diagram ........................................................505
Diagnostic Procedure ..............................................507
Component Inspection .............................................510
IDLE AIR CONTROL VALVE (IACV) - AUXILIARY
AIR CONTROL............................................................ 511
Description ............................................................... 511
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................512
ECM Terminals and Reference Value .....................512
Wiring Diagram ........................................................513
Diagnostic Procedure ..............................................515
Component Inspection .............................................519
CLOSED THROTTLE POSITION SWITCH
(WHERE FITTED)........................................................520
Component Description ...........................................520
ECM Terminals and Reference Value .....................520
Wiring Diagram ........................................................521
Diagnostic Procedure ..............................................522
Component Inspection .............................................525
INTAKE VALVE TIMING CONTROL SOLENOID
VALVE..........................................................................526
Component Description ...........................................526
Operation .................................................................526
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................526
ECM Terminals and Reference Value .....................526
Wiring Diagram ........................................................527
Diagnostic Procedure ..............................................529
Component Inspection .............................................531
A/T COMMUNICATION LINE......................................532
System Description ..................................................532
Wiring Diagram ........................................................533
Diagnostic Procedure ..............................................534
PARK/NEUTRAL POSITION (PNP) SWITCH............536
Component Description ...........................................536CONSULT-II Reference Value in Data Monitor
Mode ........................................................................536
ECM Terminals and Reference Value .....................536
Wiring Diagram ........................................................537
Diagnostic Procedure ..............................................538
INJECTOR...................................................................541
Component Description ...........................................541
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................541
ECM Terminals and Reference Value .....................541
Wiring Diagram ........................................................542
Diagnostic Procedure ..............................................544
Component Inspection .............................................546
IGNITION SIGNAL.......................................................547
Component Description ...........................................547
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................547
ECM Terminals and Reference Value .....................547
Wiring Diagram ........................................................548
Diagnostic Procedure ..............................................551
Component Inspection .............................................555
START SIGNAL...........................................................557
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................557
ECM Terminals and Reference Value .....................557
Wiring Diagram ........................................................558
Diagnostic Procedure ..............................................559
FUEL PUMP.................................................................561
System Description ..................................................561
Component Description ...........................................561
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................561
ECM Terminals and Reference Value .....................562
Wiring Diagram ........................................................563
Diagnostic Procedure ..............................................564
Component Inspection .............................................566
POWER STEERING OIL PRESSURE SWITCH.........567
Component Description ...........................................567
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................567
ECM Terminals and Reference Value .....................567
Wiring Diagram ........................................................568
Diagnostic Procedure ..............................................569
Component Inspection .............................................570
REFRIGERANT PRESSURE SENSOR......................572
Description ...............................................................572
ECM Terminals and Reference Value .....................572
Wiring Diagram ........................................................573
Diagnostic Procedure ..............................................575
ELECTRICAL LOAD SIGNAL.....................................578
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................578
CONTENTS(Cont'd)
EC-6
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
+Fuel tank 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
Swirl control valve control*4Swirl control valve control sole-
noid*4
*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-31
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-32
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-35
+At high engine speeds.
+When the engine coolant temperature becomes excessively high.
+When operating power steering during low engine speed or low vehicle speed.
+When engine speed is excessively low.
+When the refrigerant pressure is excessively high or low.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNJEC0017Input/Output Signal ChartNJEC0017S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor Vehicle speed
Fuel cut
controlInjectors PNP switch Neutral position
Throttle position sensor Throttle position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS) Engine speed
Camshaft position sensor (PHASE) Engine speed and cylinder number
If the engine speed is above 3,950 rpm with no load, (for example, in Neutral and engine speed over 4,000
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,150 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªMultiport Fuel Injection (MFI) Systemº,
EC-32.
Evaporative Emission System
DESCRIPTIONNJEC0018
SEF916WA
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Air Conditioning Cut Control (Cont'd)
EC-36
ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
NJEC0034S02
ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
D ATA
MONI-
TORD ATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STA-
TUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUTCamshaft position sensor
(PHASE)XEngine
speed
XEngine
speed
XEngine
speed
X
Crankshaft position sensor
(POS)X*3
Mass air flow sensor X X X
Engine coolant temperature
sensorXXXXX
Heated oxygen sensor 1
(front)X X X X*3 X*3
Heated oxygen sensor 2
(rear)X*3 X X X*3 X*3
Vehicle speed sensorXXXX
Throttle position sensor X X X
Fuel tank temperature sensor X X
EGR temperature sensor*4 X*3 X X
Intake air temperature sensor X*3 X X X
Knock sensor X
Ignition switch (start signal) X X
Closed throttle position
switch*4X*3 X X
Closed throttle position switch
(throttle position sensor sig-
nal)XX
Air conditioner switch X X
Refrigerant pressure sensor X X
Park/Neutral position (PNP)
switchX*3 X X
Power steering oil pressure
switchXX
Electrical load X X
Heater fan switch X X
Battery voltage X X
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-84
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
HO2S2 MNTR (B1)
[RICH/LEAN]j+Display of heated oxygen sensor 2 (rear)
signal:
RICH ... means the amount of oxygen after
three way catalyst is relatively small.
LEAN ... means the amount of oxygen after
three way catalyst is relatively large.+When the engine is stopped, a cer-
tain value is indicated.
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is displayed.
BATTERY VOLT [V]j+The power supply voltage of ECM is dis-
played.
THRTL POS SEN [V]jj+The throttle position sensor signal voltage is
displayed.
FUEL T/TMP SE
[ÉC] or [ÉF]*+The fuel temperature judged from the fuel
tank temperature sensor signal voltage is
displayed.
INT/A TEMP SE
[ÉC] or [ÉF]j+The intake air temperature determined by
the signal voltage of the intake air tempera-
ture sensor is indicated.
EGR TEMP SEN [V]*jj+The signal voltage of the EGR temperature
sensor is displayed.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is
displayed regardless of the starter
signal.
CLSD THL POS
[ON/OFF]jj+Indicates idle position [ON/OFF] computed
by ECM according to the throttle position
sensor signal.
CLSD THL/P SW
[ON/OFF]*j+Indicates mechanical contact [ON/OFF]
condition of the closed throttle position
switch.
AIR COND SIG
[ON/OFF]jj+Indicates [ON/OFF] condition of the air con-
ditioner switch as determined by the air
conditioning signal.
P/N POSI SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the PNP
switch signal.
PW/ST SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition of the power
steering oil pressure switch determined by
the power steering oil pressure switch sig-
nal.
LOAD SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the elec-
trical load signal and/or lighting switch.
ON ... rear defogger is operating and/or
lighting switch is on.
OFF ... rear defogger is not operating and
lighting switch is not on.
IGNITION SW
[ON/OFF]j+Indicates [ON/OFF] condition from ignition
switch.
HEATER FAN SW
[ON/OFF]j+Indicates [ON/OFF] condition from the
heater fan switch.
INJ PULSE-B1
[msec]j+Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.+When the engine is stopped, a cer-
tain computed value is indicated.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-88
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Crankshaft position sensor (POS)
circuit22EC-328
Camshaft position sensor
(PHASE) circuit3 2 3 EC-335
Mass air flow sensor circuit11222 22 2EC-187
Heated oxygen sensor 1 (front)
circuit1232 22 2EC-216,
224
Engine coolant temperature sen-
sor circuit112323223 2EC-201,
203
Throttle position sensor circuit 1 222222 2EC-207
Incorrect throttle position sensor
adjustment31 11111 1EC-519
Vehicle speed sensor circuit 2 3 3 3 EC-370
Knock sensor circuit 2 3 EC-324
ECM 22333333333EC-391,
154
Start signal circuit 2EC-558
PNP switch circuit 3 3 3 3 3 EC-437
Power steering oil pressure switch
circuit2 3 3 EC-568
Electrical load signal circuit 3 3 EC-578
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Symptom Matrix Chart (Cont'd)
EC-156