
ENGINE CONTROL SYSTEM
SECTION
EC
CONTENTS
QG
TROUBLE DIAGNOSIS - INDEX..................................10
Alphabetical & P No. Index for DTC .........................10
PRECAUTIONS.............................................................16
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER².............16
Precautions for On Board Diagnostic (OBD)
System of Engine and A/T.........................................16
Engine Fuel & Emission Control System ..................17
Wiring Diagrams and Trouble Diagnosis ...................19
PREPARATION.............................................................20
Special Service Tools ................................................20
Commercial Service Tools .........................................20
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM.........................................................................21
Engine Control Component Parts Location ...............21
Circuit Diagram ..........................................................25
System Diagram ........................................................26
Vacuum Hose Drawing ..............................................27
System Chart .............................................................28
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION...............................................29
Multiport Fuel Injection (MFI) System .......................29
Electronic Ignition (EI) System ..................................31
Air Conditioning Cut Control ......................................32
Fuel Cut Control (at no load & high engine
speed) ........................................................................33
Evaporative Emission System ...................................33
Positive Crankcase Ventilation ..................................37
BASIC SERVICE PROCEDURE...................................38
Fuel Pressure Release ..............................................38
Fuel Pressure Check .................................................38
Fuel Pressure Regulator Check ................................39
Injector .......................................................................39
How to Check Idle Speed and Ignition Timing ..........41
Preparation ................................................................42
Inspection Procedure .................................................45
Idle Air Volume Learning ...........................................55ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION...............................................................57
Introduction ................................................................57
Two Trip Detection Logic ...........................................57
Emission-related Diagnostic Information ...................58
NATS (Nissan Anti-theft System) ..............................72
Malfunction Indicator (MI) ..........................................72
OBD System Operation Chart (With Euro-OBD
Models Only)..............................................................76
CONSULT-II ...............................................................81
Generic Scan Tool (GST) ..........................................92
TROUBLE DIAGNOSIS - INTRODUCTION..................94
Introduction ................................................................94
Work Flow ..................................................................96
TROUBLE DIAGNOSIS - BASIC INSPECTION...........98
Basic Inspection.........................................................98
TROUBLE DIAGNOSIS - GENERAL
DESCRIPTION.............................................................122
DTC Inspection Priority Chart..................................122
Fail-safe Chart .........................................................123
Symptom Matrix Chart .............................................124
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................128
Major Sensor Reference Graph in Data Monitor
Mode ........................................................................130
ECM Terminals and Reference Value .....................132
TROUBLE DIAGNOSIS - SPECIFICATION VALUE..140
Description ...............................................................140
Testing Condition .....................................................140
Inspection Procedure ...............................................140
Diagnostic Procedure ..............................................141
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT.....................................................................144
Description ...............................................................144
Diagnostic Procedure ..............................................144
TROUBLE DIAGNOSIS FOR POWER SUPPLY........145
Main Power Supply and Ground Circuit ..................145
DTC P0100 MASS AIR FLOW SENSOR (MAFS)......152
Component Description ...........................................152

Wiring DiagramNJEC0056
YEC963
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Wiring Diagram
EC-154

4 CHECK POWER SUPPLY
1. Disconnect mass air flow sensor harness connector.
JEF105Y
2. Turn ignition switch ªONº.
3. Check voltage between terminal 2, 4 and ground with CONSULT-II or tester.
SEF297X
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-6
+Harness for open or short between ECM relay and mass air flow sensor
+Harness for open or short between mass air flow sensor and ECM
©Repair harness or connectors.
6 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow sensor harness connector terminal 3 and ECM terminal 73.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 7.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Diagnostic Procedure (Cont'd)
EC-156

7 CHECK INPUT SIGNAL CIRCUIT
1. Check harness continuity between mass air flow sensor harness connector terminal 1 and ECM terminal 61.
Refer to wiring diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK MASS AIR FLOW SENSOR
Refer to ªComponent Inspectionº, EC-157.
OK or NG
OK©GO TO 9.
NG©Replace mass air flow sensor.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-144.
©INSPECTION END
SEF993W
SEF987W
Component InspectionNJEC0058MASS AIR FLOW SENSORNJEC0058S011. Turn ignition switch ªONº.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 61 (Mass air flow sen-
sor signal) and ground.
Conditions Voltage V
Ignition switch ªONº (Engine stopped.) Less than 1.2
Idle (Engine is warmed-up to normal operating
temperature.)1.0 - 1.7
2,500 rpm (Engine is warmed-up to normal oper-
ating temperature.)1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.7 to Approx. 4.0
*: Check for linear voltage rise in response to increases to about 4,000 rpm in
engine speed.
4. If the voltage is out of specification, disconnect mass air flow
sensor harness connector and connect it again. Repeat above
check.
5. If NG, remove mass air flow sensor from air duct. Check hot
film for damage or dust.
DTC P0100 MASS AIR FLOW SENSOR (MAFS)QG
Diagnostic Procedure (Cont'd)
EC-157

3 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF380Y
3. Check harness continuity between mass air flow sensor terminal 3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check harness for open or short between mass air flow sensor and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor terminal 1 and ECM terminal 224. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0100 MASS AIR FLOW SENYD
Diagnostic Procedure (Cont'd)
EC-570

NJEL0311
Use the chart below to find out what each wiring
diagram code stands for.
Refer to the wiring diagram code in the alphabetical
index to find the location (page number) of each
wiring diagram.
Code Section Wiring Diagram Name
ISTSIG AT A/T 1ST Signal
2NDSIG AT A/T 2ND Signal
3RDSIG AT A/T 3RD Signal
4THSIG AT A/T 4TH Signal
A/C, M HA Manual Air Conditioner
A/CCUT EC Air Conditioner Cut Control
AAC/V EC IACV-AAC Valve
AACVLV EC IACV-AAC Valve
ABS BR Anti-lock Brake System
APS EC Accelerator Position Sensor
AT/C EC A/T Control
ATCONT EC A/T Control
ATDIAG EC A/T Diagnosis Communication Line
AUDIO EL Audio
BA/FTS AT A/T Fluid Temperature Sensor and
TCM Power Supply
BACK/L EL Back-up Lamp
BRK/SW EC Brake Pedal Position Switch
CHARGE SC Charging System
CHIME EL Warning Chime
CIGAR EL Cigarette Lighter
CKPS EC Crankshaft Position Sensor (POS)
CKPS EC Crankshaft Position Sensor (TDC)
CLOCK EL Clock
COOL/F EC Cooling Fan Control
D/LOCK EL Power Door Lock
DEF EL Rear Window Defogger
DTRL EL Headlamp Ð With Daytime Light
System
ECMRLY EC ECM Relay
ECTS EC Engine Coolant Temperature Sensor
EGR/TS EC EGR Temperature Sensor
EGRC1 EC EGR Function
EGVC/V EC EGR Volume Control Valve
ENGSS AT Engine Speed Signal
Code Section Wiring Diagram Name
F/FOG EL Front Fog Lamp
F/PUMP EC Fuel Pump
FRO2 EC Front Heated Oxygen Sensor (Non
E-OBD)
FRO2/H EC Front Heated Oxygen Sensor Heater
(Non E-OBD)
FTS AT A/T Fluid Temperature Sensor
FUEL EC Fuel Injection System Function
GLOW EC Glow Control System
H/AIM EL Headlamp Aiming Control System
H/LAMP EL Headlamp
H/SEAT EL Heated Seat
HEATER HA Heater System
HLC EL Headlamp Washer
HORN EL Horn
IATS EC Intake Air Temperature Sensor
IATSEN EC Intake Air Temperature Sensor
IGN/SG EC Ignition Signal
ILL EL Illumination
INJECT EC Injector
INJPMP EC Injection Pump
INT/L EL Spot, Vanity Mirror, Personal and
Trunk Room Lamps
IVC EC Intake Valve Timing Control Solenoid
Valve
IVC/V EC Intake Valve Timing Control Solenoid
Valve
KS EC Knock Sensor
LOAD EC Load Signal
LPSV AT Line Pressure Solenoid Valve
MAFS EC Mass Air Flow Sensor
MAIN AT Main Power Supply and Ground Cir-
cuit
MAIN EC Main Power Supply and Ground Cir-
cuit
METER EL Speedometer, Tachometer, Temp.
and Fuel Gauges
MIL/DL EC MIL and Data Link Connectors
MIRROR EL Door Mirror
MULTI EL Multi-remote Control System
NATS EL Nissan Anti-Theft System
WIRING DIAGRAM CODES (CELL CODES)
EL-367

Heated oxygen sensor (HO2S) heater
(rear) ............................................ EC-243, 389
Heated oxygen sensor (rear) ......... EC-214, 222,
229, 237, 383
Heated seat ............................................. EL-163
Height (Dimensions) ................................... GI-43
High clutch ............................................... AT-394
Hood ............................................................ BT-7
Horn ......................................................... EL-135
How to erase DTC for OBD system .. EC-68, 71,
522
I
IACV-AAC valve .............................. EC-313, 418
IATS - Wiring diagram .................... EC-160, 370
IGN/SG - Wiring diagram ........................ EC-452
ILL - Wiring diagram .................................. EL-72
INJECT - Wiring diagram ........................ EC-447
INT/L - Wiring diagram .............................. EL-87
IVC - Wiring diagram ...................... EC-331, 433
Identification plate ...................................... GI-40
Idle air control (IAC) system ........... EC-313, 418
Idle air control valve (IACV) ............ EC-313, 418
Idle speed ......................................... EC-41, 536
Ignition timing ............................................ EC-41
Illumination ................................................. EL-71
Injection nozzle ....................................... EC-509
Injector removal and installation ............... EC-39
Input shaft (FF M/T) ............... MT-36, 64, 93, 98
Instrument panel ........................................ BT-25
Intake air temperature sensor ......... EC-158, 369
Intake valve timing control solenoid
valve ............................................ EC-329, 432
Interior lamp on-off control ........................ EL-77
Interior lamp ............................................... EL-76
Interior ........................................................ BT-31
J
Jacking points ............................................ GI-45
Joint connector (J/C) ............................... EL-372
Junction box (J/B) .................................... EL-369
K
Keyless entry system - See Multi-remote control
system ..................................................... EL-220
Knock sensor (KS) .......................... EC-268, 269
Knuckle spindle ........................................... AX-5
L
LOAD - Wiring diagram .......................... EC-481
Length (Dimensions) .................................. GI-43
License lamp ............................................. EL-53Lifting points ............................................... GI-46
Line pressure solenoid valve ................... AT-230
Line pressure test (A/T) ............................. AT-82
Liquid gasket application ...................... EM-4, 76
Location of electrical units ....................... EL-319
Lock, door .................................................. BT-21
Low and reverse brake ............................ AT-406
Lubricant (R134a) A/C .............................. HA-86
Lubricants ................................................. MA-20
Lubrication circuit (engine) .................... LC-4, 26
M
M/T major overhaul ....................... MT-30, 54, 92
M/T removal and installation ..................... MT-23
MAFS - Wiring diagram .................. EC-154, 566
MAIN - Wiring diagram ................... EC-145, 560
MAJOR OVERHALL ................................ AT-349
MIL & Data link connectors circuit .......... EC-488
MIL/DL - Wiring diagram ................. EC-488, 701
MIRROR - Wiring diagram ...................... EL-167
Magnet clutch ............................................ HA-89
Mainshaft (M/T) .................... MT-39, 69, 93, 103
Malfunction indicator lamp (MIL) ...... EC-72, 523
Manual air conditioner - Wiring
diagram .................................................. HA-27
Manual transaxle number .......................... GI-42
Mass air flow sensor (MAFS) ......... EC-152, 566
Master cylinder (clutch) ............................. CL-11
Meter .......................................................... EL-89
Mirror defogger ........................................ EL-138
Mirror, door ................................................ BT-72
Misfire ...................................................... EC-262
Mode door control linkage
adjustment ............................................. HA-47
Model variation ........................................... GI-38
Molding - See Exterior ............................... BT-47
Multi-remote control system .................... EL-220
Multiport fuel injection (MFI) system ......... EC-29
Multiport fuel injection precautions ............... GI-6
N
NATS (Nissan Anti-theft System)
precautions ................................................... GI-3
NATS (Nissan Anti-theft System) ............ EL-234
NATS - Wiring diagram ............................ EL-237
NVH troubleshooting (AX) ........................... AX-3
NVH troubleshooting (BR) .......................... BR-6
NVH troubleshooting (MT) ........................ MT-13
NVH troubleshooting (ST) ........................... ST-5
NVH troubleshooting (SU) ........................ SU-16
NVH troubleshooting CL ............................. CL-4
NVIS (Nissan vehicle immobiliser sys-
tem) precautions ....................................... GI-3
Neutral position switch .................... EC-364, 441
ALPHABETICAL INDEX
IDX-5