+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)
DESCRIPTIONNLEC1345Input/Output Signal ChartNLEC1345S01
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
Camshaft position sensor Engine speed
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-569.
Evaporative Emission System
DESCRIPTIONNLEC1346
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.
EVAP canister purge volume control solenoid valve is controlled by ECM. When the engine operates, the flow
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
SR20DE
Air Conditioning Cut Control (Cont'd)
EC-573
rate of vapor controlled by EVAP canister purge volume control solenoid valve is proportionally regulated as
the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
SEF917W
INSPECTIONNLEC1347EVAP CanisterNLEC1347S01Check EVAP canister as follows:
1. Block port B. Orally blow air through port A. Check that air
flows freely through port C with check valve resistance.
2. Block port A. Orally blow air through port B. Check that air
flows freely through port C.
SEF918W
SEF943S
Fuel Tank Vacuum Relief Valve (Built into fuel filler cap)NLEC1347S021. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
Pressure:
15.3 - 20.0 kPa (0.15 - 0.20 bar, 0.156 - 0.204 kg/cm
2,
2.22 - 2.90 psi)
Vacuum:
þ6.0 to þ3.4 kPa (þ0.060 to þ0.034 bar, þ0.061 to
þ0.035 kg/cm
2, þ0.87 to þ0.50 psi)
3. If out of specification, replace fuel filler cap as an assembly.
Evaporative Emission (EVAP) Canister Purge Volume
Control Solenoid Valve
NLEC1347S03Refer to EC-857.
Checking EVAP Vapour LinesNLEC1347S051. Visually inspect vapor lines for leaks, cracks, damage, loose
connections, chafing and deterioration.
2. Inspect vacuum relief valve of fuel tank filler cap for clogging,
sticking, etc. Refer to next page.
ENGINE AND EMISSION BASIC CONTROL SYSTEM
DESCRIPTION
SR20DE
Evaporative Emission System (Cont'd)
EC-574
SEF094Y
SEF214Y
Fuel Pressure ReleaseNLEC1351Before disconnecting fuel line, release fuel pressure from fuel
line to eliminate danger.
WITH CONSULT-IINLEC1351S011. Start engine.
2. Perform ªFUEL PRESSURE RELEASEº in ªWORK SUP-
PORTº mode with CONSULT-II.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF.
JEF086Y
WITHOUT CONSULT-IINLEC1351S021. Remove fuse for fuel pump. Refer to fuse block cover for fuse
location.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF and reconnect fuel pump fuse.
SEF775Z
Fuel Pressure CheckNLEC1352+When reconnecting fuel line, always use new clamps.
+Make sure that clamp screw does not contact adjacent
parts.
+Use a torque driver to tighten clamps.
+Use Pressure Gauge to check fuel pressure.
+Do not perform fuel pressure check with system operat-
ing. Fuel pressure gauge may indicate false readings.
1. Release fuel pressure to zero.
2. Disconnect fuel hose from fuel feed tube (engine side).
3. Install pressure gauge between fuel hose and fuel feed tube.
4. Start engine and check for fuel leakage.
5. Read the indication of fuel pressure gauge.
At idle speed:
With vacuum hose connected
Approximately 235 kPa (2.35 bar, 2.4 kg/cm
2,34
psi)
With vacuum hose disconnected
Approximately 294 kPa (2.94 bar, 3.0 kg/cm
2,43
psi)
BASIC SERVICE PROCEDURESR20DE
Fuel Pressure Release
EC-577
If results are unsatisfactory, perform Fuel Pressure Regulator
Check, EC-578.
SEF718B
Fuel Pressure Regulator CheckNLEC13531. Stop engine and disconnect fuel pressure regulator vacuum
hose from intake manifold collector.
2. Plug intake manifold collector with a rubber cap.
3. Connect variable vacuum source to fuel pressure regulator.
4. Start engine and read indication of fuel pressure gauge as
vacuum is changed.
Fuel pressure should decrease as vacuum increases. If results
are unsatisfactory, replace fuel pressure regulator.
Injector
REMOVAL AND INSTALLATIONNLEC1746
SEF324Z
1. Release fuel pressure to zero.
2. Remove accelerator wire bracket.
3. Remove EVAP canister purge volume control solenoid valve
and the bracket.
BASIC SERVICE PROCEDURESR20DE
Fuel Pressure Regulator Check
EC-578
4. Remove ventilation hose.
5. Disconnect injector harness connectors.
6. Disconnect fuel pressure regulator vacuum hose from intake
manifold collector.
7. Disconnect fuel hoses from fuel tube assembly.
8. Remove injectors with fuel tube assembly.
SEF703X
9. Expand and remove clips securing fuel injectors.
10. Extract fuel injectors straight from fuel tubes.
+Be careful not to damage injector nozzles during removal.
+Do not bump or drop fuel injectors.
11. Carefully install O-rings, including the one used with the pres-
sure regulator.
+Lubricate O-rings with a smear of engine oil.
+Be careful not to damage O-rings with service tools or
finger nails or clips. Do not expand or twist O-rings.
+Discard old clips; replace with new ones.
12. Position clips in grooves on fuel injectors.
+Make sure that protrusions of fuel injectors are aligned
with cutouts of clips after installation.
13. Align protrusions of fuel tubes with those of fuel injectors.
14. After properly inserting fuel injectors, check to make sure that
fuel tube protrusions are engaged with those of fuel injectors,
and that flanges of fuel tubes are engaged with clips.
SEF828X
15. Tighten fuel tube assembly mounting nuts in two stages.
: Tightening torque N´m (kg-m, ft-lb)
1st stage:
9.4 - 10.7 (0.95 - 1.1, 6.9 - 7.9)
2nd stage:
21 - 26 (2.1 - 2.7, 16 - 19)
16. Install all removed parts in the reverse order of removal.
CAUTION:
After properly connecting fuel tube assembly to injector and
fuel hose, check connection for fuel leakage.
SEF910X
THROTTLE OPENER (WHERE FITTED)NLEC1747InspectionNLEC1747S011. Start engine and let it idle.
2. Confirm the amount of the rod moves ªLº more than 3.0 mm
(0.118 in), the throttle drum becomes free from the rod of the
throttle opener.
If NG, go to next step.
If OK, inspection is complete.
BASIC SERVICE PROCEDURESR20DE
Injector (Cont'd)
EC-579
7) Distance traveled while MI is activated.
8) Others
WORK SUPPORT MODENLEC1365S04
WORK ITEM CONDITION USAGE
TP SW/TP SEN IDLE POSI ADJ+FOLLOW THE BASIC INSPECTION INSTRUCTION IN
THE SERVICE MANUAL.When adjusting the idle throttle
position
IGNITION TIMING ADJ+IGNITION TIMING FEEDBACK CONTROL WILL BE
HELD BY TOUCHING ªSTARTº. AFTER DOING SO,
ADJUST IGNITION TIMING WITH A TIMING LIGHT
BY TURNING THE CAMSHAFT POSITION SENSOR.When adjusting initial ignition tim-
ing
FUEL PRESSURE RELEASE+FUEL PUMP WILL STOP BY TOUCHING ªSTARTº
DURING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.When releasing fuel pressure
from fuel line
IDLE AIR VOL LEARN+THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM.When learning the idle air volume
SELF-LEARNING CONT+THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL
COEFFICIENT.When clear the coefficient of self-
learning control value
TARGET IDLE RPM ADJ*+IDLE CONDITION When setting target idle speed
*: This function is not necessary in the usual service procedure.
SELF DIAGNOSTIC MODENLEC1365S05DTC and 1st Trip DTCNLEC1365S0501Regarding items of ªDTC and 1st trip DTCº, refer to
ªTROUBLE DIAGNOSIS Ð INDEXº, EC-550.
Freeze Frame Data and 1st Trip Freeze Frame DataNLEC1365S0502
Freeze frame data
item*Description
DIAG TROUBLE
CODE
[PXXXX]+Engine Control component part/control system has a trouble code, it is displayed as ªPXXXXº. (Refer
to ªAlphabetical & P No. Index for DTCº, EC-550.)
FUEL SYS-B1+ªFuel injection system statusº at the moment a malfunction is detected is displayed.
+One mode in the following is displayed.
ªMODE 2º: Open loop due to detected system malfunction
ªMODE 3º: Open loop due to driving conditions (power enrichment, deceleration enrichment)
ªMODE 4º: Closed loop - using oxygen sensor(s) as feedback for fuel control
ªMODE 5º: Open loop - has not yet satisfied condition to go to closed loop
CAL/LD VALUE [%]+The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [ÉC]
or [ÉF]+The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRIM-B1 [%]+ªLong-term fuel trimº at the moment a malfunction is detected is displayed.
+The long-term fuel trim indicates much more gradual feedback compensation to the base fuel sched-
ule than short-term fuel trim.
S-FUEL TRIM-B1 [%]+ªShort-term fuel trimº at the moment a malfunction is detected is displayed.
+The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel
schedule.
ENGINE SPEED [rpm]+The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED [km/h]
or [mph]+The vehicle speed at the moment a malfunction is detected is displayed.
ABSOL TH´P/S [%]+The throttle valve opening angle at the moment a malfunction is detected is displayed.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONSR20DE
CONSULT-II (Cont'd)
EC-610
Monitored item [Unit]ECM
input
signalsMain
signalsDescription Remarks
INT/A TEMP SE
[ÉC] or [ÉF]jj+The intake air temperature determined by the
signal voltage of the intake air temperature
sensor is indicated.
EGR TEMP SEN [V]
(where fitted)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.
AIR COND SIG
[ON/OFF]jj+Indicates [ON/OFF] condition of the air condi-
tioner switch as determined by the air condi-
tioning 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 signal.
LOAD SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the electri-
cal load signal and/or lighting switch.
ON ... rear defogger is operating and/or light-
ing 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.
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.
IGN TIMING [BTDC]j+Indicates the ignition timing computed by
ECM according to the input signals.
CAL/LD VALUE [%]+ªCalculated load valueº indicates the value of
the current airflow divided by peak airflow.
ABSOL TH.P/S [%]+ªAbsolute throttle position sensorº indicates
the throttle opening computed by ECM
according to the signal voltage of the throttle
position sensor.
MASS AIRFLOW
[gm/s]+Indicates the mass airflow computed by ECM
according to the signal voltage of the mass
air flow sensor.
IACV-AAC/V [step]j+Indicates the IACV-AAC valve control value
computed by ECM according to the input sig-
nals.
PURG VOL C/V [%]+Indicates the EVAP canister purge volume
control solenoid valve computed by the ECM
according to the inpuct signals.
+The opening becomes larger as the value
increases.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONSR20DE
CONSULT-II (Cont'd)
EC-612
Symptom Matrix ChartNLEC1372SYSTEM Ð ENGINE CONTROL SYSTEMNLEC1372S01
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
Fuel Fuel pump circuit11232 22 3 2EC-1032
Fuel pressure regulator system334444444 4EC-578
Injector circuit11232 22 2EC-1021
Evaporative emission system334444444 4EC-573
Air Positive crankcase ventilation sys-
tem334444444 41EC-576
Incorrect idle speed adjustment 3 31111 1EC-623
IACV-AAC valve circuit112332222 2 2EC-863, 995
Ignition Incorrect ignition timing adjust-
ment33111 11 1EC-623
Ignition circuit11222 22 2EC-900, 1004
EGR
(where
fitted)EGR volume control valve circuit2233 3EC-841
EGR system212333223 3EC-834, 841,
921
Main power supply and ground circuit22333 33 23 2EC-671
Air conditioner circuit223333333 3 2HAsection
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONSR20DE
Symptom Matrix Chart
EC-648