Multiport Fuel Injection (MFI) System
DESCRIPTIONNJEC0014Input/Output Signal ChartNJEC0014S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
Fuel injec-
tion & mix-
ture ratio
controlInjector Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 (front) Density of oxygen in exhaust gas
Throttle position sensorThrottle position
Throttle valve idle position
PNP switch Gear position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Air conditioner switch Air conditioner operation
Knock sensor Engine knocking condition
Electrical load Electrical load signal
Battery Battery voltage
Power steering oil pressure switch Power steering operation
Heated oxygen sensor 2 (rear)* Density of oxygen in exhaust gas
* Under normal conditions, this sensor is not for engine control operation.
Basic Multiport Fuel Injection SystemNJEC0014S02The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the camshaft position sensor and the mass air
flow sensor.
Various Fuel Injection Increase/Decrease CompensationNJEC0014S03In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.
+During warm-up
+When starting the engine
+During acceleration
+Hot-engine operation
+When selector lever is changed from ªNº to ªDº (A/T models)
+High-load, high-speed operation
+During deceleration
+During high engine speed operation
+During high vehicle speed operation (M/T models)
+Extremely high engine coolant temperature
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Multiport Fuel Injection (MFI) System
EC-29
JEF091Y
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. Disconnect throttle position sensor harness connector (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. 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)
NOTE:
If idle air volume learning cannot be performed successfully,
proceed as follows:
1)Check that throttle valve is fully closed.
2)Check PCV valve operation.
3)Check that downstream of throttle valve is free from air
leakage.
4)Adjust closed throttle position switch and reset memory.
(Refer to Basic Inspection, EC-98.)
5)When the above three items check out OK, engine com-
ponent parts and their installation condition are question-
able. Check and eliminate the cause of the problem.
It is useful to perform ªTROUBLE DIAGNOSIS Ð SPECIFI-
CATION VALVEº, EC-140.
6)If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and per-
form ªIdle air volume learningº all over again:
+Engine stalls.
+Erroneous idle.
+Blown fuses related to the IACV-AAC valve system.
BASIC SERVICE PROCEDUREQG
Idle Air Volume Learning (Cont'd)
EC-56
MI Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor 1 (front) function, start engine in the Diagnostic Test Mode II and warm
it up until engine coolant temperature indicator points to the middle of the gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the
MI comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.
OBD System Operation Chart (With Euro-OBD
Models Only)
NJEC0033RELATIONSHIP BETWEEN MI, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMSNJEC0033S01+When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.
+When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MI will come on. For details, refer to ªTwo Trip Detection Logicº on
EC-57.
+The MI will go off after the vehicle is driven 3 times with no malfunction. The drive is counted only when
the recorded driving pattern is met (as stored in the ECM). If another malfunction occurs while counting,
the counter will reset.
+The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A)
without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and Fuel
Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times (driv-
ing pattern C) without the same malfunction recurring. The ªTIMEº in ªSELF-DIAGNOSTIC RESULTSº
mode of CONSULT-II will count the number of times the vehicle is driven.
+The 1st trip DTC is not displayed when the self-diagnosis results in ªOKº for the 2nd trip.
SUMMARY CHARTNJEC0033S02
Items Fuel Injection System Misfire Other
MI (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no display) 80 (pattern C) 80 (pattern C) 40 (pattern A)
1st Trip DTC (clear) 1 (pattern C), *1 1 (pattern C), *1 1 (pattern B)
1st Trip Freeze Frame Data (clear) *1, *2 *1, *2 1 (pattern B)
For details about patterns ªBº and ªCº under ªFuel Injection Systemº and ªMisfireº, see EC-78.
For details about patterns ªAº and ªBº under ªOtherº, see EC-80.
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Malfunction Indicator (MI) (Cont'd)
EC-76
When you are inspecting the circuit by gently shaking (or twist-
ing) the suspicious connectors, components and harness in
the ªDTC Confirmation Procedureº, the moment a malfunction
is found the DTC/1st trip DTC will be displayed. (Refer to
GI-22, ªIncident Simulation Testsº.)
2) ªMANU TRIGº
+If the malfunction is displayed as soon as ªDATA MONITORº
is selected, reset CONSULT-II to ªMANU TRIGº. By selecting
ªMANU TRIGº you can monitor and store the data. The data
can be utilized for further diagnosis, such as a comparison with
the value for the normal operating condition.
SEF714Y
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
CONSULT-II (Cont'd)
EC-91
FUNCTIONNJEC0035S03
Diagnostic test mode Function
MODE 1 READINESS TESTSThis mode gains access to current emission-related data values, including analog
inputs and outputs, digital inputs and outputs, distance traveled while MI is activated
and system status information.
MODE 2 (FREEZE DATA)This mode gains access to emission-related data value which were stored by ECM
during the freeze frame. (For details, refer to ªFreeze Frame Dataº, EC-84.)
MODE 3 DTCsThis mode gains access to emission-related power train trouble codes which were
stored by ECM.
MODE 4 CLEAR DIAG INFOThis mode can clear all emission-related diagnostic information. This includes:
+Clear number of diagnostic trouble codes (MODE 1)
+Clear diagnostic trouble codes (MODE 3)
+Clear trouble code for freeze frame data (MODE 1)
+Clear freeze frame data (MODE 2)
+Reset status of system monitoring test (MODE 1)
+Clear on board monitoring test results (MODE 6 and 7)
MODE 6 (ON BOARD TESTS)This mode accesses the results of on board diagnostic monitoring tests of specific
components/systems that are not continuously monitored.
MODE 7 (ON BOARD TESTS)This mode enables the off board test drive to obtain test results for emission-related
powertrain components/systems that are continuously monitored during normal driving
conditions.
MODE 8 Ð This mode is not applicable on this vehicle.
MODE 9 (CALIBRATION ID)This mode enables the off-board (External test equipment) to request specific vehicle
information such as Vehicle Identification Number (VIN) and Calibration IDs.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Generic Scan Tool (GST) (Cont'd)
EC-93
14 RESET THROTTLE POSITION SENSOR IDLE POSITION MEMORY
With CONSULT-II
NOTE:
Always warm up engine to normal operating temperature. If engine is cool, the throttle position sensor idle posi-
tion memory will not be reset correctly.
1. Confirm that proper vacuum is applied. Refer to Test No. 10.
2. Attach blind cap to vacuum port from which vacuum hose to throttle opener was disconnected.
3. Start engine.
4. Warm up engine to normal operating temperature.
5. Select ªTP SW/TP SEN IDLE POSI ADJº in ªWORK SUPPORTº mode.
6. Stop engine. (Turn ignition switch ªOFFº.)
7. Turn ignition switch ªONº and wait at least 5 seconds.
SEF864V
8. Turn ignition switch ªOFFº and wait at least 9 seconds.
9. Repeat steps 7 and 8 until ªCLSD THL POSº signal changes to ªONº.
SEF715Y
©GO TO 19.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection (Cont'd)
EC-105
17 ADJUSTMENT THROTTLE POSITION SWITCH CLOSED POSITION-II
Without CONSULT-II
1. Temporarily tighten sensor body fixing bolts as follows.
+Gradually move the sensor body clockwise and stop it when the continuity comes to exist, then temporarily
tighten sensor body fixing bolts.
SEF964W
2. Make sure two or three times that the continuity exists when the throttle valve is closed and continuity does not exist
when it is opened.
3. Remove 0.05 mm (0.0020 in) feeler gauge then insert 0.15 mm (0.0059 in) feeler gauge.
4. Make sure two or three times that the continuity does not exist when the throttle valve is closed.
5. Tighten throttle position sensor.
6. Check the continuity again.
Continuity does not exist while closing the throttle valve.
OK or NG
OK©GO TO 18.
NG©GO TO 16.
18 RESET THROTTLE POSITION SENSOR IDLE POSITION MEMORY
Without CONSULT-II
NOTE:
Always warm up engine to normal operating temperature. If engine is cool, the throttle position sensor idle posi-
tion memory will not be reset correctly.
1. Confirm that proper vacuum is applied. Refer to Test No. 10.
2. Attach blind cap to vacuum port from which vacuum hose to throttle opener was disconnected.
3. Start engine.
4. Warm up engine to normal operating temperature.
5. Stop engine. (Turn ignition switch ªOFFº.)
6. Turn ignition switch ªONº and wait at least 5 seconds.
SEF864V
7. Turn ignition switch ªOFFº and wait at least 9 seconds.
8. Repeat steps 6 and 7, 20 times.
©GO TO 19.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection (Cont'd)
EC-108
6 ADJUST THROTTLE POSITION SENSOR IDLE POSITION
With CONSULT-II
1. Loosen throttle position sensor fixing bolts.
2. Turn throttle position sensor body clockwise or counterclockwise until ªTHRTL POS SENº indication becomes 0.35 to
0.65V.
SEF964W
3. Tighten the throttle position sensor fixing bolts.
©GO TO 7.
7 RESET THROTTLE POSITION SENSOR IDLE POSITION MEMORY
With CONSULT-II
NOTE:
Always warm up engine to normal operating temperature. If engine is cool, the throttle position sensor idle posi-
tion memory will not be reset correctly.
1. Start engine and warm it up to normal operating temperature.
2. Select ªCLSD THL POSº in ªDATA MONITORº mode with CONSULT-II.
3. Stop engine. (Turn ignition switch ªOFFº.)
4. Turn ignition switch ªONº and wait at least 5 seconds.
SEF864V
5. Turn ignition switch ªOFFº and wait at least 9 seconds.
6. Repeat steps 4 and 6 until ªCLSD THL POSº indication changes to ªONº.
SEF061Y
©GO TO 11.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection (Cont'd)
EC-115