
NJCL0004
NVH Troubleshooting ChartNJCL0004S01Use the chart below to help you find the cause of the symptom. The numbers indicate the order of the inspec-
tion. If necessary, repair or replace these parts.
CLUTCHNJCL0004S0101
Reference pageCL-10
CL-10
CL-11
CL-14
Refer to EM-137, ªRemoval and Installationº (QG engine model) and
EM-137, ªRemoval and Installationº (YD engine model).
CL-17 (RS5F30A, RS5F70A), CL-20 (RS5F50A)
CL-22
CL-22
CL-22
CL-22
CL-22
CL-22
CL-22
CL-22
CL-23
CL-23
CL-23
CL-23
SUSPECTED PARTS
(Possible cause)
CLUTCH PEDAL (Free play out of adjustment)
CLUTCH LINE (Air in line)
MASTER CYLINDER PISTON CUP (Damaged)
OPERATING CYLINDER PISTON CUP (Damaged)
ENGINE MOUNTING (Loose)
RELEASE BEARING (Worn, dirty or damaged)
CLUTCH DISC (Out of true)
CLUTCH DISC (Runout is excessive)
CLUTCH DISC (Lining broken)
CLUTCH DISC (Dirty or burned)
CLUTCH DISC (Oily)
CLUTCH DISC (Worn out)
CLUTCH DISC (Hardened)
CLUTCH DISC (Lack of spline grease)
DIAPHRAGM SPRING (Damaged)
DIAPHRAGM SPRING (Out of tip alignment)
PRESSURE PLATE (Distortion)
FLYWHEEL (Distortion)
SymptomClutch grabs/chatters 1 2 2 2 2 2
Clutch pedal spongy 1 2 2
Clutch noisy 1
Clutch slips 1 2 2 3 4 5
Clutch does not disen-
gage1234 55555 5667
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting Chart
CL-4

ComponentsNJCL0027
SCL842
RemovalNJCL00281. Remove manual transaxle from vehicle. Refer to MT-27,
ªRemovalº.
2. Move withdrawal lever enough to remove release bearing, and
remove release bearing from clutch withdrawal lever.
3. Remove dust cover.
4. Remove retainer spring from withdrawal lever.
SCL733
InspectionNJCL0029+Replace the release bearing if it is seized, damaged, faulty in
rotation direction, or has poor aligning function.
+Replace the withdrawal lever if its contact surface is worn
abnormally.
+Replace the dust cover if it is deformed or cracked.
InstallationNJCL00301. Apply a coat of grease to parts as instructed in the following
cautions and notes before installation.
CAUTION:
+Be sure to apply grease to the clutch components.
Otherwise, abnormal noise, poor clutch disengagement,
or clutch damage may occur. Wipe the excess grease off
completely, because it may cause the clutch components
to slip and shudder.
+Keep the clutch disc facing, pressure plate, and flywheel
free of oil and grease.
CLUTCH RELEASE MECHANISMRS5F50A
Components
CL-20

ECM Terminals and Reference Value .....................578
Wiring Diagram ........................................................579
Diagnostic Procedure - Load Signal - .....................583
Diagnostic Procedure - Heater Control Panel
(Fan Switch) - ..........................................................589
Component Inspection .............................................590
MI & DATA LINK CONNECTORS..............................591
Wiring Diagram ........................................................591
SERVICE DATA AND SPECIFICATIONS (SDS).......593
Fuel Pressure Regulator..........................................593
Idle Speed and Ignition Timing ................................593
Mass Air Flow Sensor..............................................593
Intake Air Temperature Sensor ................................593
Engine Coolant Temperature Sensor ......................593
Throttle Position Sensor ..........................................593
Heated Oxygen Sensor 1 Heater (Front) ................593
Heated Oxygen Sensor 2 Heater (Rear).................593
Fuel Tank Temperature Sensor (Where Fitted) .......594
EGR Volume Control Valve (Where Fitted) .............594
EGR Temperature Sensor (Where Fitted) ...............594
EVAP Canister Purge Volume Control Valve ..........594
IACV-AAC Valve ......................................................594
Injector .....................................................................594
Ignition Coil with Power Transistor ..........................594
Condenser ...............................................................594
Fuel Pump ...............................................................594
Crankshaft Position Sensor (POS) ..........................595
Camshaft Position Sensor (PHASE) .......................595
YD
TROUBLE DIAGNOSIS - INDEX................................596
Alphabetical & P No. Index for DTC .......................596
PRECAUTIONS...........................................................598
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER²...........598
Engine Fuel & Emission Control System ................599
Precautions ..............................................................600
Wiring Diagrams and Trouble Diagnosis .................601
PREPARATION...........................................................602
Special Service Tools ..............................................602
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM.......................................................................603
Engine Control Component Parts Location .............603
Circuit Diagram ........................................................606
System Diagram ......................................................608
System Chart ...........................................................609
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION.............................................610
Fuel Injection Control System .................................610
Fuel Injection Timing Control System...................... 611
Air Conditioning Cut Control ....................................612Fuel Cut Control (at no load & high engine
speed) ......................................................................612
Crankcase Ventilation System .................................613
BASIC SERVICE PROCEDURE.................................614
Injection Tube and Injection Nozzle ........................614
Electronic Control Fuel Injection Pump ...................618
Fuel Filter .................................................................625
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION.............................................................627
DTC and MI Detection Logic ...................................627
Diagnostic Trouble Code (DTC) ..............................627
Malfunction Indicator (MI) ........................................628
CONSULT-II .............................................................632
TROUBLE DIAGNOSIS - INTRODUCTION................637
Introduction ..............................................................637
Work Flow ................................................................639
TROUBLE DIAGNOSIS - BASIC INSPECTION.........641
Basic Inspection.......................................................641
TROUBLE DIAGNOSIS - GENERAL
DESCRIPTION.............................................................646
Symptom Matrix Chart .............................................646
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................656
Major Sensor Reference Graph in Data Monitor
Mode ........................................................................658
ECM Terminals and Reference Value .....................659
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT.....................................................................665
Description ...............................................................665
Diagnostic Procedure ..............................................665
TROUBLE DIAGNOSIS FOR POWER SUPPLY........666
Main Power Supply and Ground Circuit ..................666
DTC P0100 MASS AIR FLOW SEN...........................673
Component Description ...........................................673
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................673
ECM Terminals and Reference Value .....................673
On Board Diagnosis Logic.......................................673
DTC Confirmation Procedure ..................................673
Wiring Diagram ........................................................675
Diagnostic Procedure ..............................................677
DTC P0115 COOLANT TEMP SEN............................680
Description ...............................................................680
On Board Diagnosis Logic.......................................680
DTC Confirmation Procedure ..................................680
Wiring Diagram ........................................................682
Diagnostic Procedure ..............................................683
DTC P0120 ACCEL POS SENSOR............................685
Description ...............................................................685
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................685
ECM Terminals and Reference Value .....................685
CONTENTS(Cont'd)
EC-7

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

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

Symptom Matrix ChartNJEC0041SYSTEM Ð ENGINE CONTROL SYSTEMNJEC0041S01
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
Fuel Fuel pump circuit11232 22 3 2EC-561
Fuel pressure regulator sys-
tem334444444 4EC-41
Injector circuit11232 22 2EC-542
Evaporative emission sys-
tem334444444 4EC-36
Air Positive crankcase ventila-
tion system334444444 41EC-39
Incorrect idle speed adjust-
ment3 3 1 1 1 1 1 EC-43
IACV-AAC valve circuit112332222 2 2EC-376
Ignition Incorrect ignition timing
adjustment33111 11 1EC-43
Ignition circuit11222 22 2EC-547
EGR EGR volume control valve
circuit2233 3EC-352
EGR system212333223 3EC-343,
352, 425
Main power supply and ground circuit22333 33 23 2EC-178
Air conditioner circuit223333333 3 2HAsection
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Symptom Matrix Chart
EC-155