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-32
+At high engine speeds.
+When the engine coolant temperature becomes excessively high.
+When operating power steering during low engine speed or low vehicle speed.
+When engine speed is excessively low.
+When the refrigerant pressure is excessively high or low.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNJEC0017Input/Output Signal ChartNJEC0017S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor Vehicle speed
Fuel cut
controlInjectors PNP switch Neutral position
Throttle position sensor Throttle position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS) Engine speed
Camshaft position sensor (PHASE) Engine speed and cylinder number
If the engine speed is above 3,950 rpm with no load, (for example, in Neutral and engine speed over 4,000
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,150 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªMultiport Fuel Injection (MFI) Systemº,
EC-29.
Evaporative Emission System
DESCRIPTIONNJEC0018
SEF916WA
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Air Conditioning Cut Control (Cont'd)
EC-33
SEF217Z
SEF454Y
SEF455Y
Idle Air Volume LearningNJEC0562DESCRIPTIONNJEC0562S01ªIdle Air Volume Learningº is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:
+Each time IACV-AAC valve, throttle body or ECM is replaced.
+Idle speed or ignition timing is out of specification.
PRE-CONDITIONINGNJEC0562S02Before performing ªIdle Air Volume Learningº, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
+Battery voltage: More than 12.9V (At idle)
+Engine coolant temperature: 70 - 99ÉC (158 - 210ÉF)
+PNP switch: ON
+Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
+Cooling fan motor: Not operating
+Steering wheel: Neutral (Straight-ahead position)
+Vehicle speed: Stopped
+Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until ªFLUID
TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
OPERATION PROCEDURENJEC0562S03With CONSULT-IINJEC0562S03011. Turn ignition switch ªONº and wait at least 1 second.
2. Turn ignition switch ªOFFº and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic ªPRE-CONDITION-
INGº (previously mentioned) are in good order.
5. Turn ignition switch ªOFFº and wait at least 9 seconds.
6. Start the engine and let it idle for at least 28 seconds.
7. Select ªIDLE AIR VOL LEARNº in ªWORK SUPPORTº mode.
8. Touch ªSTARTº and wait 20 seconds.
9. Make sure that ªCMPLTº is displayed on CONSULT-II screen.
If ªINCMPº is displayed, ªIdle Air Volume Learningº will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Ignition timing M/T: 8±5É BTDC
A/T: 10±5É BTDC (in ªPº or ªNº position)
Without CONSULT-IINJEC0562S03021. Turn ignition switch ªONº and wait at least 1 second.
BASIC SERVICE PROCEDUREQG
Inspection Procedure (Cont'd)
EC-55
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
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-82
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
HO2S2 MNTR (B1)
[RICH/LEAN]j+Display of heated oxygen sensor 2 (rear)
signal:
RICH ... means the amount of oxygen after
three way catalyst is relatively small.
LEAN ... means the amount of oxygen after
three way catalyst is relatively large.+When the engine is stopped, a cer-
tain value is indicated.
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is displayed.
BATTERY VOLT [V]j+The power supply voltage of ECM is dis-
played.
THRTL POS SEN [V]jj+The throttle position sensor signal voltage is
displayed.
FUEL T/TMP SE
[ÉC] or [ÉF]*+The fuel temperature judged from the fuel
tank temperature sensor signal voltage is
displayed.
INT/A TEMP SE
[ÉC] or [ÉF]j+The intake air temperature determined by
the signal voltage of the intake air tempera-
ture sensor is indicated.
EGR TEMP SEN [V]*jj+The signal voltage of the EGR temperature
sensor is displayed.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is
displayed regardless of the starter
signal.
CLSD THL POS
[ON/OFF]jj+Indicates idle position [ON/OFF] computed
by ECM according to the throttle position
sensor signal.
CLSD THL/P SW
[ON/OFF]*j+Indicates mechanical contact [ON/OFF]
condition of the closed throttle position
switch.
AIR COND SIG
[ON/OFF]jj+Indicates [ON/OFF] condition of the air con-
ditioner switch as determined by the air
conditioning signal.
P/N POSI SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the PNP
switch signal.
PW/ST SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition of the power
steering oil pressure switch determined by
the power steering oil pressure switch sig-
nal.
LOAD SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the elec-
trical load signal and/or lighting switch.
ON ... rear defogger is operating and/or
lighting switch is on.
OFF ... rear defogger is not operating and
lighting switch is not on.
IGNITION SW
[ON/OFF]j+Indicates [ON/OFF] condition from ignition
switch.
HEATER FAN SW
[ON/OFF]j+Indicates [ON/OFF] condition from the
heater fan switch.
INJ PULSE-B1
[msec]j+Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.+When the engine is stopped, a cer-
tain computed value is indicated.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-86
Basic InspectionNJEC1785MODELS WITH THROTTLE POSITION SWITCHNJEC1785S01Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
On vehicle equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
+Air conditioner switch is OFF,
+Rear window defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem, or a current need for scheduled
maintenance.
2. Open engine hood and check the following:
+Harness connectors for improper connections
+Vacuum hoses for splits, kinks and improper connections
+Wiring for improper connections, pinches and cuts
+Air cleaner clogging
+Hoses and ducts for leaks
SEF983U
©GO TO 2.
2 CHECK THROTTLE OPENER OPERATION-I
Confirm that there is a clearance between throttle drum and stopper.
SEF850Y
OK or NG
OK©GO TO 4.
NG©GO TO 3.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection
EC-98
35 CHECK IGNITION TIMING AGAIN
Check ignition timing again. Refer to Test No. 31.
OK or NG
OK©GO TO 37.
NG©GO TO 36.
36 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-27, ªInstallationº.
OK or NG
OK©GO TO 34.
NG©1. Repair the timing chain installation.
2. GO TO 32.
37 ERASE UNNECESSARY DTC
After this inspection, unnecessary DTC No. might be displayed.
Erase the stored memory in ECM and TCM (Transmission control module).
Refer to ªHow to Erase Emission-Related Diagnostic Informationº, EC-68 or EC-75 and AT-50, ªHOW TO ERASE DTCº.
OK or NG
©INSPECTION END
MODELS WITHOUT THROTTLE POSITION SWITCHNJEC1785S02Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
On vehicle equipped with daytime light system, set lighting
switch to the 1st position to light only small lamps.
+Air conditioner switch is OFF,
+Rear window defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem, or a current need for scheduled
maintenance.
2. Open engine hood and check the following:
+Harness connectors for improper connections
+Vacuum hoses for splits, kinks and improper connections
+Wiring for improper connections, pinches and cuts
+Air cleaner clogging
+Hoses and ducts for leaks
SEF983U
©GO TO 2.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection (Cont'd)
EC-113
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
Crankshaft position sensor (POS)
circuit22EC-272
Camshaft position sensor
(PHASE) circuit3 2 3 EC-278
Mass air flow sensor circuit11222 22 2EC-152
Heated oxygen sensor 1 (front)
circuit1232 22 2EC-176,
183
Engine coolant temperature sen-
sor circuit112323223 2EC-163,
165
Throttle position sensor circuit 1 222222 2EC-168
Incorrect throttle position sensor
adjustment31 11111 1EC-98
Vehicle speed sensor circuit 2 3 3 3 EC-309
Knock sensor circuit 2 3 EC-268
ECM 22333333333EC-327,
123
Start signal circuit 2EC-461
PNP switch circuit 3 3 3 3 3 EC-364
Power steering oil pressure switch
circuit2 3 3 EC-471
Electrical load signal circuit 3 3 EC-480
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG
Symptom Matrix Chart (Cont'd)
EC-125