
ENGINE CONTROL SYSTEM
SECTION
EC
CONTENTS
ZD30DDTi
TROUBLE DIAGNOSIS - INDEX....................................7
Alphabetical & Numerical Index for DTC ....................7
PRECAUTIONS...............................................................9
Precautions ..................................................................9
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM.........................................................................12
Engine Control Component Parts Location ...............12
Circuit Diagram ..........................................................16
System Diagram ........................................................17
Vacuum Hose Drawing ..............................................18
System Chart .............................................................19
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION...............................................20
Fuel Injection Control System ...................................20
Fuel Injection Timing Control System........................22
Air Conditioning Cut Control ......................................22
Fuel Cut Control (at no load & high engine
speed) ........................................................................22
Crankcase Ventilation System ...................................23
BASIC SERVICE PROCEDURE...................................24
Injection Tube and Injection Nozzle ..........................24
Electronic Control Fuel Injection Pump .....................27
Air Bleeding ...............................................................32
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION...............................................................33
DTC and MI Detection Logic .....................................33
Diagnostic Trouble Code (DTC) ................................33
Malfunction Indicator (MI) ..........................................34
CONSULT-II ...............................................................39
TROUBLE DIAGNOSIS - INTRODUCTION..................46
Introduction ................................................................46
Work Flow ..................................................................48
TROUBLE DIAGNOSIS - BASIC INSPECTION...........50
Basic Inspection.........................................................50
TROUBLE DIAGNOSIS - GENERAL
DESCRIPTION...............................................................56
Symptom Matrix Chart ...............................................56CONSULT-II Reference Value in Data Monitor
Mode ..........................................................................66
Major Sensor Reference Graph in Data Monitor
Mode ..........................................................................68
ECM Terminals and Reference Value .......................69
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT.......................................................................78
Description .................................................................78
Diagnostic Procedure ................................................78
TROUBLE DIAGNOSIS FOR POWER SUPPLY..........79
Main Power Supply and Ground Circuit ....................79
DTC 0102 MASS AIR FLOW SEN................................88
Component Description .............................................88
CONSULT-II Reference Value in Data Monitor
Mode ..........................................................................88
ECM Terminals and Reference Value .......................88
On Board Diagnosis Logic.........................................88
DTC Confirmation Procedure ....................................89
Wiring Diagram ..........................................................90
Diagnostic Procedure ................................................92
DTC 0103 COOLANT TEMP SEN................................95
Description .................................................................95
On Board Diagnosis Logic.........................................95
DTC Confirmation Procedure ....................................95
Wiring Diagram ..........................................................96
Diagnostic Procedure ................................................97
DTC 0104 VEHICLE SPEED SEN................................99
Description .................................................................99
ECM Terminals and Reference Value .......................99
On Board Diagnosis Logic.........................................99
Overall Function Check ...........................................100
Wiring Diagram ........................................................101
Diagnostic Procedure ..............................................103
DTC 0203 ACCEL POS SW (F/C)..............................104
Description ...............................................................104
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................104
ECM Terminals and Reference Value .....................104
On Board Diagnosis Logic.......................................104

CONSULT-II Reference Value in Data Monitor
Mode ........................................................................281
ECM Terminals and Reference Value .....................282
Wiring Diagram ........................................................283
Diagnostic Procedure ..............................................284
AIR CONDITIONER CONTROL..................................289
Wiring Diagram ........................................................289
MI (MIL) & DATA LINK CONNECTORS.....................291
Wiring Diagram ........................................................291
SERVICE DATA AND SPECIFICATIONS (SDS)........292
General Specifications .............................................292
Injection Pump Numbers .........................................292
Injection Nozzle .......................................................292
Engine Coolant Temperature Sensor ......................292
Crankshaft Position Sensor (TDC) ..........................292
Glow Plug ................................................................292
Accelerator Position Sensor ....................................292
EGR Volume Control Valve .....................................292
TD27Ti
TROUBLE DIAGNOSIS - INDEX................................293
Alphabetical & Numerical Index for DTC ................293
PRECAUTIONS AND PREPARATION........................295
Special Service Tools ..............................................295
Engine Fuel & Emission Control System ................297
Precautions ..............................................................298
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM.......................................................................300
Engine Control Component Parts Location .............300
Circuit Diagram ........................................................302
System Diagram ......................................................303
Vacuum Hose Drawing ............................................304
System Chart ...........................................................305
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION.............................................306
Fuel Injection System ..............................................306
Fuel Injection Timing System ..................................309
Air Conditioning Cut Control .................................... 311
Fuel Cut Control (at high engine speed) ................. 311
Glow Control ............................................................ 311
CRANKCASE VENTILATION SYSTEM......................312
Description ...............................................................312
Blow-by Control Valve .............................................312
Ventilation Hose .......................................................312
INJECTION NOZZLE...................................................313
Removal and Installation .........................................313
Disassembly (No.2-4nozzle) ...............................313
Inspection (No.2-4nozzle) ...................................314
Cleaning (No.2-4nozzle) .....................................314
Assembly (No.2-4nozzle) ....................................315
Test and Adjustment ................................................316
ELECTRONIC FUEL INJECTION PUMP....................318Removal ...................................................................318
Installation ................................................................319
Disassembly and Assembly .....................................320
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION.............................................................321
DTC and MI Detection Logic ...................................321
Diagnostic Trouble Code (DTC) ..............................321
Malfunction Indicator (MI) ........................................322
CONSULT-II .............................................................327
TROUBLE DIAGNOSES.............................................334
Introduction ..............................................................334
Diagnostic Worksheet ..............................................335
Work Flow ................................................................336
Description for Work Flow .......................................337
Basic Inspection.......................................................338
Symptom Matrix Chart .............................................340
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................343
Major Sensor Reference Graph in Data Monitor
Mode ........................................................................345
ECM Terminals and Reference Value .....................346
TROUBLE DIAGNOSIS FOR POWER SUPPLY........352
Wiring Diagram ........................................................352
Diagnostic Procedure ..............................................353
DTC P0100 MASS AIR FLOW SEN...........................356
Component Description ...........................................356
On Board Diagnosis Logic.......................................356
DTC Confirmation Procedure ..................................356
Wiring Diagram ........................................................357
Diagnostic Procedure ..............................................359
Component Inspection .............................................360
DTC P0115 COOLANT TEMP SEN............................361
Component Description ...........................................361
On Board Diagnosis Logic.......................................361
DTC Confirmation Procedure ..................................361
Wiring Diagram ........................................................362
Diagnostic Procedure ..............................................363
Component Inspection .............................................364
DTC P0120 ACCEL POS SENSOR............................365
Component Description ...........................................365
On Board Diagnosis Logic.......................................365
DTC Confirmation Procedure A (For General
Plausibility) ...............................................................365
DTC Confirmation Procedure B (For Accelerator
Sticking) ...................................................................366
Wiring Diagram ........................................................367
Diagnostic Procedure ..............................................368
Component Inspection .............................................371
DTC P0180 FUEL TEMP SENSOR............................372
Component Description ...........................................372
On Board Diagnosis Logic.......................................372
DTC Confirmation Procedure ..................................372
CONTENTS(Cont'd)
EC-4

Precautions
IAlways use a 12 volt battery as power source.
IDo not attempt to disconnect battery cable while engine is
running.
IBefore 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.
IBefore removing parts, turn off ignition switch and then
disconnect battery ground cable.
IDo not disassemble ECM.
IIf 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.
IWhen ECM is removed for inspection, make sure to ground
the ECM mainframe.
IWhen connecting ECM harness connector, tighten secur-
ing bolt until the gap between the orange indicators disap-
pears.
: 3.0 - 5.0 N×m (0.3 - 0.5 kg-m, 26 - 43 in-lb)
IWhen 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 terminal, when connecting pin connectors.
ISecurely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in the circuit, thus resulting in damage
to ICs.
IKeep ECM harness at least 10 cm (3.9 in) away from adja-
cent harnesses, to prevent an ECM system malfunction
SEF706Y
SEC220B
SEF665S
SEF308Q
SEF291H
PRECAUTIONSZD30DDTi
EC-9

IDo not disconnect pump harness connector with engine
running.
IDo not disassemble electronic fuel injection pump.
If NG, take proper action.
IDo not disassemble injection nozzle.
If NG, replace injection nozzle.
IEven a slight leak in the air intake system can cause seri-
ous problems.
IDo not shock or jar the crankshaft position sensor (TDC).
IDo not depress accelerator pedal when starting.
IImmediately after starting, do not rev up engine unneces-
sarily.
IDo not rev up engine just prior to shutdown.
IWhen installing C.B. ham radio or a mobile phone, be sure
to observe the following as it may adversely affect elec-
tronic control systems depending on its installation loca-
tion.
1) Keep the antenna as far as possible away from the ECM.
2) Keep the antenna feeder line more than 20 cm (7.9 in) away
from the harness of electronic controls.
Do not let them run parallel for a long distance.
3) Adjust the antenna and feeder line so that the standing-
wave ratio can be kept smaller.
4) Be sure to ground the radio to vehicle body.
SEF437Y
SEF709Y
SEF708Y
PRECAUTIONSZD30DDTi
Precautions (Cont'd)
EC-11

Engine Control Component Parts Location
MEC988D
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
EC-12

MEC989D
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
Engine Control Component Parts Location
(Cont'd)
EC-13

MEC990D
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
Engine Control Component Parts Location
(Cont'd)
EC-14

MEC029E
ENGINE AND EMISSION CONTROL OVERALL SYSTEMZD30DDTi
Engine Control Component Parts Location
(Cont'd)
EC-15