ENGINE CONTROL SYSTEMSECTION
EC
CONTENTS
DIAGNOSTIC TROUBLE CODE INDEX .........................1
Alphabetical & Numerical Index for DTC ....................1
PRECAUTIONS AND PREPARATION ............................2
Special Service Tools ..................................................2
Commercial Service Tool .............................................3
Supplemental Restraint System (SRS) ``AIR
BAG'' and ``SEAT BELT PRE-TENSIONER''...............4
PRECAUTIONS AND PREPARATION ............................5
Engine Fuel & Emission Control System ....................5
Precautions ..................................................................6
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM ........................................................................\
...8
ECCS-D Component Parts Location ...........................8
Circuit Diagram .......................................................... 11
System Diagram ........................................................12
Vacuum Hose Drawing ..............................................13
System Chart .............................................................14
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION ...............................................15
Fuel Injection System ................................................15
Fuel Injection Timing System ....................................18
Air Conditioning Cut Control ......................................19
Fuel Cut Control (at no load & high engine
speed) ........................................................................\
20
CRANKCASE VENTILATION SYSTEM ........................21
Description .................................................................21
Inspection...................................................................21
INJECTION NOZZLE .....................................................22
Removal and Installation ...........................................22
Disassembly (No. 2 - 4 nozzles) ...............................22
Inspection (No. 2 - 4 nozzles) ...................................23
Cleaning (No. 2 - 4 nozzles) .....................................23
Assembly (No. 2 - 4 nozzles) ....................................24
Test and Adjustment ..................................................25
ELECTRONIC FUEL INJECTION PUMP ......................27
Removal .....................................................................27
Installation ..................................................................28
Disassembly and Assembly .......................................29
ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION ...............................................................30
DTC and MIL Detection Logic ...................................30
Diagnostic Trouble Code (DTC) ................................30 Malfunction Indicator Lamp (MIL) ..............................31
CONSULT ..................................................................36
TROUBLE DIAGNOSIS Ð Introduction ......................42
Introduction ................................................................42
Diagnostic Worksheet ................................................43
TROUBLE DIAGNOSIS Ð Work Flow ........................44
Work Flow ..................................................................44
Description for Work Flow .........................................45
TROUBLE DIAGNOSIS Ð Basic Inspection ..............46
Basic Inspection.........................................................46
TROUBLE DIAGNOSIS Ð General Description ........48
Symptom Matrix Chart ...............................................48
CONSULT Reference Value in Data Monitor
Mode ........................................................................\
..51
Major Sensor Reference Graph in Data Monitor
Mode ........................................................................\
..53
ECM Terminals and Reference Value .......................54
TROUBLEDIAGNOSISFORPOWERSUPPLY ..........63
MainPowerSupplyandGroundCircuit....................63
TROUBLE DIAGNOSIS FOR ``CAM POS SEN
(PUMP)''(DTC11) .........................................................69
CamshaftPositionSensor(CMPS)(PUMP).............69
TROUBLEDIAGNOSISFOR``MASSAIRFLOW
SEN''(DTC12) ..............................................................74
MassAirFlowSensor(MAFS)..................................74
TROUBLEDIAGNOSISFOR``COOLANTTEMP
SEN''(DTC13) ..............................................................79
EngineCoolantTemperature(ECT)Sensor.............79
TROUBLEDIAGNOSISFOR``VEHICLESPEED
SEN''(DTC14) ..............................................................83
VehicleSpeedSensor(VSS)....................................83
TROUBLEDIAGNOSISFOR``CONTSLEEVPOS
SEN''(DTC15) ..............................................................87
ControlSleevePositionSensor(CSPS)...................87
TROUBLEDIAGNOSISFOR``ADJUST
RESISTOR''(DTC17) ...................................................92
AdjustmentResistor...................................................92
TROUBLEDIAGNOSISFOR``F/INJF/B2''
(DTC18),``F/INJF/B''(DTC22),``ELECTRIC
GOV''(DTC25) ..............................................................96
ElectricGovernor.......................................................96
EC
TROUBLEDIAGNOSISFOR``F/INJTIMGF/B''
(DTC21).......................................................................101
InjectionTimingControlValve.................................101
TROUBLEDIAGNOSISFOR``ACCELPOSSW
(F/C)''(DTC23) ...........................................................106
AcceleratorSwitch(F/C)..........................................106
TROUBLEDIAGNOSISFOR``ECM1''(DTC27),
``ECM2''(DTC31) .......................................................111
EngineControlModule(ECM)-ECCS-DControl
Module.....................................................................111
TROUBLEDIAGNOSISFOR``OVERHEAT''
(DTC28) .......................................................................113
CoolingFan(Overheat)...........................................113
TROUBLEDIAGNOSISFOR``I/CINT/ATEMP
SEN''(DTC33) ............................................................122
ChargeAirTemperatureSensor..............................122
TROUBLEDIAGNOSISFOR``NEEDLELIFT
SEN''(DTC34) ............................................................126
NeedleLiftSensor(NLS)........................................126
TROUBLE DIAGNOSIS FOR ``FUEL CUT S/V 1''
(DTC 36), ``FCV SHORT'' (DTC 37), ``FUEL CUT
S/V2''(DTC38) ...........................................................130
FuelCutSolenoidValve..........................................130
TROUBLE DIAGNOSIS FOR ``FUEL TEMP
SENSOR''(DTC42) ....................................................135
FuelTemperatureSensor(FTS)..............................135 TROUBLE DIAGNOSIS FOR ``ACCEL POS
SENSOR''(DTC43)
....................................................139
AcceleratorPositionSensor....................................139
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN
(TDC)''(DTC47) ..........................................................144
CrankshaftPositionSensor(TDC)..........................144
TROUBLEDIAGNOSISFOR``GOVCUT
CIRCUIT''(DTC48) .....................................................149
GovernorCutCircuit................................................149
TROUBLEDIAGNOSESFORNON-DETECTABLE
ITEMS ........................................................................\
...151
GlowControlSystem...............................................151
EGRC-SolenoidValveA,BandThrottleControl
SolenoidValve.........................................................156
StartSignal..............................................................163
AcceleratorPositionSwitch.....................................165
Park/NeutralPositionSwitch...................................170
A/TControl...............................................................175
ChargeAirCoolerFanControl................................178
HeatUpSwitch........................................................183
AirConditionerControl............................................187
MIL&DataLinkConnectors...................................188
SERVICEDATAANDSPECIFICATIONS(SDS) ........189
GeneralSpeci®cations.............................................189
InjectionNozzle.......................................................189
InspectionandAdjustment......................................189
When you read wiring diagrams:
+ Read GI section, ``HOW TO READ WIRING DIAGRAMS''.
+ See EL section, ``POWER SUPPLY ROUTING'' for power distribution circuit.
When you perform trouble diagnoses, read GI section, ``HOW TO FOLLOW FLOW CHART IN
TROUBLE DIAGNOSES'' and ``HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL
INCIDENT''.
System Chart
Camshaft position sensor (PUMP)c
ECM
(ECCS-D
control
module)
Crankshaft position sensor (TDC)c
Control sleeve position sensorc
Fuel temperature sensorc
Engine coolant temperature sensorc
Needle lift sensorc
Accelerator position sensorc
Accelerator position switchc
Accelerator switch (F/C)c
Neutral position switchc
Ignition switchc
Battery voltagec
Vehicle speed sensorc
Air conditioner switchc
Mass air ¯ow sensorc
Charge air temperature sensorc
Heat up switchc
Fuel injection controlcElectric governor
Fuel injection timing controlcInjection timing control valve
Fuel cut controlcFuel cut solenoid valve
Glow control systemcGlow relay & glow lamp
On board diagnostic systemcMalfunction indicator lamp
(On the instrument panel)
EGR valve & throttle control
valve controlcEGRC-solenoid valve A, B &
throttle control solenoid valve
Cooling fan controlcCooling fan relay
Air conditioning cut controlcAir conditioner relay
Charge air cooler fan controlcCharge air cooler fan relay
ENGINE AND EMISSION CONTROL OVERALL SYSTEM
EC-14
IDLE CONTROL
Input/output signal line
Engine coolant temperature sensorcEngine coolant temperature
ECM
cElectric
governor
Crankshaft position sensor (TDC)cEngine speed
Neutral position switch
cGear position
Battery
cBattery voltage
Control sleeve position sensor
cControl sleeve position
Accelerator position switch
cIdle position
Vehicle speed sensor
cVehicle speed
Air conditioner switch
cAir conditioner signal
Heat up switch
cHeat up switch signal
When the ECM determines that the engine speed is at idle, the fuel injection system is adapted for the idle
control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the engine
to keep engine speed constant. The ECM also provides the system with a fast idle control in response to the
engine coolant temperature and heat up switch signal.
NORMAL CONTROL
Input/output signal line
Crankshaft position sensor (TDC)cEngine speed
ECM
cElectric
governorControl sleeve position sensorcControl sleeve position
Accelerator position sensor
cAccelerator position
Vehicle speed sensor
cVehicle speed
The amount of fuel injected under normal driving conditions is
determined according to sensor signals. The crankshaft position
sensor (TDC) detects engine speed and the accelerator position
sensor detects accelerator position. These sensors send signals to
the ECM.
The fuel injection data, predetermined by correlation between vari-
ous engine speeds and accelerator positions, are stored in the
ECM memory, forming a map. The ECM determines the optimal
amount of fuel to be injected using the sensor signals in compari-
son with the map.
SEF649S
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Fuel Injection System (Cont'd)
EC-16
ENGINE COOLANT TEMPERATURE COMPENSATION (During driving)
Input/output signal line
Crankshaft position sensor (TDC)cEngine speed
ECM
c
Injection
timing con-
trol valveEngine coolant temperature sensorcEngine coolant temperature
Needle lift sensor
cInjection timing
For better exhaust efficiency under cool engine conditions, the fuel
injection timing is controlled within a compensation range depend-
ing on the engine speed, engine coolant temperature and amount
of fuel injected.
Air Conditioning Cut Control
INPUT/OUTPUT SIGNAL LINE
Air conditioner switchcAir conditioner ``ON'' signal
ECM
cAir
conditioner
relayAccelerator position sensorcAccelerator valve opening angle
Vehicle speed sensor
cVehicle speed
Engine coolant temperature sensor
cEngine coolant temperature
SYSTEM DESCRIPTION
This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This continues
until the coolant temperature returns to normal.
SEF652S
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Fuel Injection Timing System (Cont'd)
EC-19
ECCS COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
SELF-DIAG-
NOSTIC
RESULTSDATA
MONITORACTIVE
TEST
ECCS COMPONENT PARTS
INPUTCamshaft position sensor (PUMP) X X
Engine coolant temperature sensor X X
Control sleeve position sensor X X
Fuel temperature sensor X X
Vehicle speed sensor X X
Accelerator position sensor X X X
Accelerator position switch X X
Accelerator switch (F/C) X X
Crankshaft position sensor (TDC) X X
Needle lift sensor X
Ignition switch (start signal) X
Neutral position switch X
Battery voltage X
Air conditioner switch X
Heat up switch X
Mass air ¯ow sensor X X
Charge air temperature sensor X
OUTPUTInjection timing control valve X X X
Fuel cut solenoid valve X X X
Glow relayXX
EGRC-solenoid valve A, B & throttle control solenoid valve X X
Cooling fan relay X X
Charge air cooler fan relay X
X: Applicable
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT (Cont'd)
EC-37
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
AIR COND SIG
[ON/OFF]
jj
+Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
IGN SW
[ON/OFF]
jj+Indicates [ON/OFF] condition from igni-
tion switch signal.
MAS AIR/FL SE [V]
jj+The signal voltage of the mass air ¯ow
sensor is displayed.+When the engine is stopped, a certain
value is indicated.
ACT INJ TIMG [É]
jj
+The actual injection timing angle deter-
mined by the ECM (an approximate
average angle between injection start
and end from TDC) is displayed.
INJ TIMG C/V [%]+Indicates the duty ratio of fuel injection
timing control valve.
DECELER F/CUT
[ON/OFF]
j
+Indicates [ON/OFF] condition from decel-
eration fuel cut signal.+When the accelerator pedal is released
quickly with engine speed at 3,000 rpm
or more, ``ON'' is displayed.
FUEL CUT S/V
[ON/OFF]
j
+The control condition of the fuel cut sole-
noid valve (determined by ECM accord-
ing to the input signal) is indicted.
+OFF ... Fuel cut solenoid valve is not
operating.
ON ... Fuel cut solenoid valve is operat-
ing.+When the fuel cut solenoid valve is not
operating, fuel is not supplied to injection
nozzles.
GLOW RLY [ON/OFF]
j
+The glow relay control condition (deter-
mined by ECM according to the input
signal) is displayed.
COOLING FAN
[LOW/HI/OFF]
j
+Indicates the control condition of the
cooling fans (determined by ECM
according to the input signal).
+LOW ... Operates at low speed.
HI ... Operates at high speed.
OFF ... Stopped.
I/C FAN RLY
[ON/OFF]
j
+Indicates the control condition of the
charge air cooler fan (determined by
ECM according to the input signals).
EGRC SOL/V A
[ON/OFF]+The control condition of the EGRC-sole-
noid valve A (determined by ECM
according to the input signal) is indi-
cated.
+OFF ... EGRC-solenoid valve A is not
operating.
ON ... EGRC-solenoid valve A is operat-
ing.
EGRC SOL/V B
[ON/OFF]+The control condition of the EGRC-sole-
noid valve B (determined by ECM
according to the input signal) is indi-
cated.
+OFF ... EGRC-solenoid valve B is not
operating.
ON ... EGRC-solenoid valve B is operat-
ing.
THROT RLY
[ON/OFF]+The control condition of the throttle con-
trol solenoid valve (determined by ECM
according to the input signal) is indi-
cated.
+OFF ... Throttle control solenoid valve is
not operating.
ON ... Throttle control solenoid valve is
operating.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT (Cont'd)
EC-39
Work Flow
CHECK IN
CHECK INCIDENT CONDITIONS.
Listen to customer complaints. (Get symptoms.).................................................
STEP I
Check andPRINT OUT(write down) Diagnostic Trouble Code (DTC).
Then clear. Also check related service bulletins for information.
...........................................
STEP II
Symptoms
collected.No symptoms, except MIL
lights up, or Malfunction
Code exists at STEP II.
Verify the symptom by driving in the condition the cus-
tomer described.
.
*1
.............................................................................................
STEP III
Normal Code
(at STEP II)
Malfunction Code
(at STEP II)
INCIDENT CONFIRMATION
Verify the DTC by performing the ``DTC CONFIRMATION PROCEDURE''.
*1
...........................................
STEP IV
cChoose the appropriate action.
Malfunction Code (at STEP II or IV) Normal Code (at both STEP II and IV)...........................................
*2STEP V
BASIC INSPECTION
SYMPTOM BASIS (at STEP I or III)
................................................................
c
Perform inspections
according to Symptom
Matrix Chart.
.
TROUBLE DIAGNOSIS FOR DTC XX.STEP VI
REPAIR/REPLACE
NGFINAL CHECK
Con®rm that the incident is completely ®xed by performing BASIC INSPECTION and
DTC CONFIRMATION PROCEDURE (or OVERALL FUNCTION CHECK). Then,
erase the unnecessary (already ®xed) DTCs in ECM.
OK...........................................
STEP VII
CHECK OUT
*1: If the incident cannot be duplicated, refer to GI section (``Incident Simulation Tests'', ``HOW TO PERFORM EFFICIENT
DIAGNOSIS FOR AN ELECTRICAL INCIDENT'').
*2: If the on board diagnostic system cannot be performed, check main power supply and ground circuit. Refer to
``TROUBLE DIAGNOSIS FOR POWER SUPPLY'', EC-63.
.
.
.
.
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS Ð Work Flow
EC-44