BASICSERVICE PROCEDURE
Idle Speedllgnition TiminglldleMixtureRatio
Adjustment
PREPARATION
• Make surethatthefollowing partsarein
good order.
(1) Battery
(2) Ignition system
(3) Engine oiland coolant levels
(4) Fuses
(5) ECM harness connector
(6) Vacuum hoses
(7) Airintake system
(Oil filler cap,oillevel gauge, etc.)
(8) Fuel pressure
(9) Engine compression
(10) Throttle valve
Overall inspection sequence
INSPECTION
•
•
•
•
•
•
On
models equipped withairconditioner,
checks shouldbecarried outwhile theair
conditioner is"OFF".
On models equipped withautomatic
transaxle, whenchecking idlespeed, ignition
timing andmixture ratio,checks shouldbe
carried outwhile shiftlever isin "N" position.
When measuring "CO"percentage, insert
probe morethan40cm (15.7 in)into tailpipe.
Turn offheadlamps, heaterblower, rear
defogger. Keep frontwheels pointed straight ahead.
Make thecheck afterthecooling fanhas
stopped.
•
Perform diagnostic testmode II
(Self-diagnostic results).
OK
Check
&
adjust ignition timing.
Check
&
adjust idlespeed.
Check heated oxygen sensor
function. NG
Repair orreplace.
NG Check heated oxygen sensor
harness. NG
Repair orreplace harness.
OK OK
Check CO%. OKReplace heatedoxygen sensor.
NG
INSPECTION END Check
emission controlparts
and repair orreplace ifneces-
sary.
EC-243
NG
Check heated oxygen sensor
function.
OK
@
START
Visually checkthefollowing:
• Air cleaner clogging
• Hoses andduct forleaks
• Electrical connectors
• Gasket (intakemanifold, cylinderhead,exhaust system)
• Throttle valveandthrottle position sensoroperation
m
Start engine andwarm itup until engine coolant temperature indicator
points tothe middle ofgauge.
Ensure enginespeedstaysbelow 1,000rpm.
1
Open engine hoodandrunengine atabout 2,000rpmforabout 2minutes
under no-load.
Ii]
Perform theDiagnostic TestMode
1\
(Self-diagnostic results).
OK ~NG
Repair orreplace components asneces-
sary.
[!J
Run engine atabout 2,000rpmforabout 2minutes underno-load.
Rev engine twoorthree times under no-load, thenrunengine atidle
speed forabout 1minute .
li]1!I
00
1.
Select "IGNITION TIMINGADJ"inWORK SUPPORT mode.
2. Touch "START" .
.
OR
00
1.
Turn offengine anddisconnect throttleposition sensorharness
connector.
2. Start engine.
Rev engine (2,000-3,000 rpm)2or 3times under no-load, thenrunengine
at idle speed.
t
Throttle position sensor
harness connector SEF785KASEF051PA
BASIC
SERVICE PROCEDURE Em
Idle Speedllgnition TiminglldleMixtureRatio
Adjustment (Cont'd)
SEF248F
SEF455Q
Malfunction indicator
lamp \
I/
'~,,/
- CHECK-
,,/
........
/ I\
Ii] •IGN TIMING ADJ.
D
IGNITION TIMINGFEEDBACK
CONTROL WILLBEHELD BY
TOUCHING START.
AFTER DOING SO,ADJUST
IGNITION TIMINGWITHA
TIMING LIGHTBYTURNING
THE CAMSHAFT POSITION
SENSOR.
I
START
I
SEF546N
EC-244
AEC804
•
Ii
L
Check ignition timingwithatiming light.
M/T:
15°::l:2°BTDC
A/T: 15°::l: 2°BTDC (inUN" position)
NG
Adjust ignition timingtothe specified valuebyturning
distributor afterloosening boltswhich secure distribu-
tor.
M/T:
15°::l:2°BTDC
.
A/T:
15°::l: 2°BTDC (inUN" position)
~IIJ
@
~
00
1.
Select
"IGNTIMING ADJ"in"WORK
SUPPORT" mode.
2. Touch "START".
OR
@
1.
Stop engine anddisconnect throttleposition
sensor harness connector.
2. Start engine.
0
Check idlespeed.
@ Read
idlespeed in"IGN TIMING ADJ"in
"WORK SUPPORT" mode.
OR
@
Checkidlespeed.
M/T:
750::l: 50rprn
A/T: 750::l: 50rprn (inUN" position)
OK NG
Rev engine (2,000-3,000 rpm)2or 3times under
no-load, thenrunengine atidle speed.
1.1
Adjust idlespeed byturning idlespeed adjusting
screw.
M/T:
750::l: 50rpm
A/T: 750::l: 50rprn (inUN" position)
II
00
Touch
"BACK".
OR
@
1.
Turn offengine andconnect throttleposition
sensor harness connector.
2. Start engine.
L
Rev engine (2,000-3,000 rpm)2or 3times under
no-load, thenrunengine atidle speed.
-.
BASIC
SERVICE PROCEDURE
[]K]
Idle Speed/Ignition Timing/IdleMixtureRatio
Adjustment (Cont'd)
@
SEF548N
/ / I
Throttle position sensor-
harness connector /
I
\ \ SEF788LASEF546N
START
•
IGN TIMING ADJ.
0
IGNITION TIMINGFEEDBACK
CONTROL WILLBEHELD BY
TOUCHING START
AFTER DOING SO,ADJUST
IGNITION TIMINGWITHA
TIMING LIGHTBYTURNING
THE CAMSHAFT POSITION
SENSOR
= ==
MONITOR
==
=
CMPS.RPM (REF)762rpm
IGN TIMING 15BTDC
CLOSED TH/POS ON
Ii
o •
IGN TIMING ADJ.
0
I- -
CONDITION SETIING--
IGN/T FEEDBACK HOLD
EC-245
BASICSERVICE PROCEDURE
mJ
Idle Speed/Ignition Timing/IdleMixtureRatio
Adjustment (Cont'd)
@
SEF909P SEF913J
RECORD
@
M
may bethe
se ofa
blem, butthis
arely thecase
II
1
Check idlespeed.
00
Read
idlespeed in"DATA
MONITOR" modewithCONSULT.
OR
@
Check
idlespeed.
M/T:
800:l: 50rpm
A/T:
800:l: 50rpm (in
uN"
position)
OK ~NG
Check IACV-AAC valveandreplace ifnec-
essary.
~
Check IACV-AAC valveharness andrepair
if necessary.
~
Check ECMfunction- bysubstituting
another knowngoodECM.
-EC
cau
pro
1II111[!]
is
r
(j)
1.
See "M/R
FIC
MNT" in"DATA
MONITOR" mode.
2. Run engine atabout 2,000rpm
for about 2minutes under
no-load.
3.
Maintain engineat2,000 rpm
under no-load (engineiswarmed
up sufficiently). Checkthatthe
monitor fluctuates between
"LEAN" and"RICH" morethan5
times during 10seconds.
1 cycle: RICH->LEAN ->RICH
2 cycles: RICH->LEAN ->RICH
->LEAN ->RICH
NG
OR
~
(j)
1.
Set "Heated oxygensensor
monitor" inthe Diagnostic Test
Mode II.
(See page EC-252.)
2. Run
engine atabout 2,000rpm
for about 2minutes under
no-load.
3.
Maintain
engineat2,000 rpm
under no-load. Checkthatthe
malfunction indicatorlampgoes
on and offmore than5times dur-
ing 10seconds.
~OK
END
SEF135K
I
MEC7118
825rpm
2000rpm
RICH
1<
NO FAIL
D
RECORD
\ I/
.........
~/"
- CHECK-
/
......
/ I\
~MONITOR
~NOFAIL
0
CAS-RPM (REF)
CMPS.RPM (REF)
MIR
FIC
MNT
1<
MONITOR
@~~
~~r
~~V
-
-~
Data linkconnector forCONSULT
(Connect CHKandIGN terminals
with asuitable harness)
II
SEF051PEC-246
ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)
FUNCTION
Diagnostictestmode Function
A technician canadjust somedevices
Work support
fasterandmore accurately byfollowing
indications onCONSULT.
Self-diagnostic results Self-diagnostic
resultscanberead and
erased quickly.
Data monitor
Input/Outputdatainthe ECM canberead.
CONSULT drivessomeactuators apart
Active test fromtheECM's andalso shifts some
parameters inaspecified range.
ECM partnumbers
ECMpartnumbers canberead.
Conducted byCONSULT insteadofatech-
Function test
niciantodetermine whethereachsystem
is "OK" or"NG".
WORK SUPPORT MODE
WORK ITEM
CONDITION USAGE
THRTL POSSENADJ
CHECKTHETHROTTLE POSITIONSENSORSIGNAL. Whenadjusting throttleposition
ADJUST ITTO THE SPECIFIED VALUEBYROTATING
sensorinitialposition
THE SENSOR BODYUNDER THEFOLLOWING CONDI-
TIONS .
• IGN SW"ON"
• ENG NOTRUNNING
• ACC PEDAL NOTPRESSED
IGNITION TIMINGADJ
•IGNITION TIMINGFEEDBACK CONTROLWILLBE
Whenadjusting initialignition
HELD BYTOUCHING "START".AFTERDOINGSO, timing
ADJUST IGNITION TIMINGWITHATIMING LIGHTBY
TURNING THECAMSHAFT POSITIONSENSOR.
IACV-AAC VALVEADJ
SETENGINE SPEEDATTHE SPECIFIED VALUEUNDER
Whenadjusting idlespeed
THE FOLLOWING CONDITIONS.
• ENGINE WARMED UP
• NO-LOAD
FUEL PRESSURE RELEASE •FUEL PUMP WILLSTOP BYTOUCHING "START"
Whenreleasing fuelpressure
DURING IDLING.
fromfuelline
CRANK AFEW TIMES AFTER ENGINE STALLS
EC-256
ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)
SELF-DIAGNOSTIC MODE
Regarding itemsdetected in"SELF-DiAG RESULTS"mode,referto"Diagnostic TroubleCode(DTC)
Chart". (Seepage EC-268.)
DATA MONITOR MODE
Monitored item ECM
Main
[Unit] input
signals Description
Remarks
signals
CMPS.RPM •Indicates theengine speedcomputed •
Accuracy becomespoorifengine
(REF) [rpm] fromtheREF signal (180'signal) of speeddropsbelow theidle rpm.
0 0
the
camshaft positionsensor. •
Ifthe signal isinterrupted whilethe
engine isrunning, anabnormal value
may beindicated .
MAS AIR/FL SE[V]
0 0
•
The sig~al voltage ofthe mass air •
When theengine isstopped, acertain
flow sensor isdisplayed. valueisindicated .
COOLAN TEMP/S •
The engine coolant temperature •
When theengine coolant temperature
rOC] orrF] (determined
bythe signal voltage ofsensor
isopen orshort-circuited,
0 0
the
engine coolant temperature sen-ECMenters fail-safe mode.The
sor) isdisplayed. engine
coolant temperature deter-
mined bythe ECM isdisplayed .
02
SEN [V]
00
•
The signal voltage ofthe heated oxy-
gen sensor isdisplayed.
M/R F/CMNT •
Display ofheated oxygen sensorsig-•
After turning ONthe ignition switch,
[RICH/LEAN] nal
during air-fuel ratiofeedback con-"RICH"
isdisplayed untilair-fuel mix-
trol: ture
ratio feedback controlbegins.
RICH ...means themixture became •
When theair-fuel ratiofeedback is
0 0
"rich",
andcontrol isbeing affected clamped,
thevalue justbefore the
toward aleaner mixture. clamping
isdisplayed continuously.
LEAN ...means themixture became
"lean", andcontrol isbeing affected
toward arich mixture .
VHCL SPEED SE •
The vehicle speedcomputed fromthe
[km/h] or[mph]
00
vehicle
speedsensor signalisdis-
played .
SA TTERY VOLT[V]
0 0
•
The power supply voltage ofECM is
displayed .
THRTL POSSEN [V]
0 0
•
The throttle position sensorsignal
voltage isdisplayed.
START SIGNAL •
Indicates [ON/OFF] conditionfromthe•
After starting theengine, [OFF]isdis-
[ON/OFF]
00
starter
signal. played
regardless ofthe starter sig-
nal.
CLSD THLIPOSI •
Indicates theclosed throttle position
[ON/OFF] [ON/OFF]
determined bythe throttle
0 0
position
sensorsignal.
ON: Closed throttle position
OFF: Other thanclosed throttle
position
NOTE:
Any monitored itemthatdoes notmatch thevehicle beingdiagnosed isdeleted fromthedisplay auto-
matically.
EC-257
•
ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Conl'd)
ACTIVE TESTMODE
TEST ITEM CONDITION JUDGEMENTCHECKITEM(REMEDY)
• Engine: Returntothe original
•Harness andconnector
FUEL INJECTION trouble
condition
Iftrouble symptom disappears,
•Fuel injectors
• Change theamount offuel
seeCHECK ITEM.
•Heated oxygen sensor
injection usingCONSULT .
• Engine: Afterwarming up,idle
IACV-AACIV the
engine.
Enginespeedchanges according •Harness andconnector
OPENING •
Change theIACV-AAC valve
tothe opening percent. •
IACV-AAC valve
opening percentusingCON-
SULT.
• Engine: Returntothe original
•Harness andconnector
ENG COOLANT trouble
condition
Iftrouble symptom disappears, •
Engine coolant temperature
• Change theengine coolant
.
TEMP see
CHECK ITEM. sensor
temperature indicationusing
•Fuel injectors
CONSULT .
• Engine: Returntothe original
trouble condition
Iftrouble symptom disappears,
IGNITION TIMING•Timing light:Set •
Adjust initialignition timing
• Retard theignition timingusingsee
CHECK ITEM.
CONSULT.
• Engine: Afterwarming up,idle •
Harness andconnector
the engine. •
Compression
POWER
•
AIC
switch "OFF"
Enginerunsrough ordies. •
Injectors
BALANCE •
Shift lever "N" •
Power transistor
• Cut offeach injector signalone •
Spark plugs
at atime using CONSULT . •
Ignition coils
• Ignition switch:ON
•Harness andconnector
COOLING FAN•
Turn thecooling fan"ON" andCooling
fanmoves andstops.
•Cooling fanmotor
"OFF" usingCONSULT .
• Ignition switch:ON(Engine
FUEL PUMP stopped)
Fuelpump relaymakes theoper- •
Harness andconnector
RELAY •
Turn thefuel pump relay"ON"
atingsound. •
Fuel pump relay
and "OFF" usingCONSULT
and listen tooperating sound.
EGRC •
Ignition switch:ON
• Turn solenoid valve"ON"and Solenoid
valvemakes anoperat- •
Harness andconnector
SOLENOID "OFF"withtheCONSULT andingsound. •
Solenoid valve
VALVE listentooperating sound.
SELF-LEARNING •
In this test, thecoefficient ofself-learning controlmixture ratioreturns tothe original coefficient by
CONT touching
"CLEAR" onthe screen.
EC-259
•
ON-BOARDDIAGNOSTIC SYSTEMDESCRIPTION
CONSULT (Cont'd)
FUNCTION TEST
CONDITION
ITEM JUDGEMENT
CHECKITEM(REMEDY)
• Ignition switch:ON
->
START
• Start signal circuit is
tested whenengine is
started byoperating the
starter. Beforecranking,
START SIGNAL batteryvoltage andengine
Startsignal: OFF
->
ON •
Harness andconnector
CIRCUIT coolanttemperature are
•Ignition switch
displayed. During
cranking, averagebattery
voltage, massairflow
sensor outputvoltage and
cranking speedaredis-
.
played .
• Ignition switch:ON
(Engine running)
Lockedposition ON
•Harness andconnector
PW/ST SIGNAL •
Power steering circuitis
•Power steering oilpres-
CIRCUIT tested
whensteering
sureswitch
wheel isrotated fullyand
•Power steering oilpump
then settoastraight lineNeutral
position OFF
running position.
• Vehicle speedsensor cir-
•Harness andconnector
VEHICLE SPEED cuitistested whenvehicle Vehiclespeedsensor inputsignal is
•Vehicle speedsensor
SEN CKT isrunning ataspeed of10 greater than4km/h (2MPH)
•Electric speedometer
km/h (6MPH) orhigher .
• After warming up,idle the
engine. •Adjust ignition timing(by
• Ignition timingadjustment
movingcrankshaft position
is checked byreading Thetiming lightindicates thesame
IGN TIMING ADJ
ignitiontimingwithatim- valueonthe screen. sensor
ordistributor)
ing light andchecking •
Camshaft positionsensor
whether itagrees with drive
mechanism
specifications. •INJECTION SYS(Injector,
fuel pressure regulator,
harness orconnector)
• Air-fuel ratiofeedback cir- •
IGNITION SYS(Spark
cuit (injection system,igni- plug,
power transistor,
ignition coil,harness or
tion system, vacuum
connector)
MIXTURE RATIO system,
etc.)istested byHeated oxygen sensorCOUNT: More
•VACUUM SYS(Intake air
TEST examining
theheated oxy-than
5times during 10seconds
leaks)
gen sensor outputat2,000
•Heated oxygen sensorcir-
rpm under non-loaded
cuit
state. •Heated oxygen sensor
operation
• Fuel pressure highorlow
• Mass airflow sensor
EC-261
•