ECM Terminals and Reference Value=NCEC0081Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
58 B Sensors' ground[Engine is running]
IWarm up condition
IIdle speedApproximately 0V
92 Y Throttle position sensor[Engine is running]
IAccelerator pedal fully released0.35 - 0.65V
[Ignition switch ªONº]
IAccelerator pedal fully depressedApproximately 4.0V
111 G Sensors' power supply[Ignition switch ªONº]Approximately 5V
On Board Diagnosis LogicNCEC0082
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0120
0120An excessively low or high voltage from the sensor is
sent to ECM while driving*.IHarness or connectors
(The throttle position sensor circuit is open or
shorted.)
IThrottle position sensor
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
Detected items Engine operating condition in fail-safe mode
Throttle position sensor
circuitThrottle position will be determined based on the injected fuel amount and the engine speed.
Therefore, acceleration will be poor.
Condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
DTC Confirmation ProcedureNCEC0083NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
IBefore performing the following procedure, confirm that
battery voltage is more than 10V at idle.
IThis test may be conducted with the drive wheels lifted in
the shop or by driving the vehicle. If a road test is
expected to be easier, it is unnecessary to lift the vehicle.
DTC P0120 THROTTLE POSITION SENSORSR20DE
ECM Terminals and Reference Value
EC-138
On Board Diagnosis LogicNCEC0188With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensor 1 (front).
The ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MI (2 trip detection logic).
Sensor Input Signal to ECMECM func-
tionActuator
Heated oxygen sensor 1 (front)Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion & mix-
ture ratio
controlInjectors
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0171
0171IFuel injection system does not operate properly.
IThe amount of mixture ratio compensation is too large.
(The mixture ratio is too lean.)IIntake air leaks
IHeated oxygen sensor 1 (front)
IInjectors
IExhaust gas leaks
IIncorrect fuel pressure
ILack of fuel
IMass air flow sensor
DTC Confirmation ProcedureNCEC0189NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
IAlways perform at a temperature above þ10ÉC (14ÉF).
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªSELF-LEARN CON-
TROLº in ªWORK SUPPORTº mode with CONSULT-II.
4) Clear the self-learning control coefficient by touching ªCLEARº.
5) Select ªDATA MONITORº mode with CONSULT-II.
6) Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 should be detected at this stage, if a
malfunction exists. If so, go to ªDiagnostic Procedureº, EC-SR-
214.
7) If it is difficult to start engine at step 6, the fuel injection sys-
tem has a malfunction.
8) Crank engine while depressing accelerator pedal. If engine
starts, go to ªDiagnostic Procedureº, EC-SR-214. If engine
does not start, visually check for exhaust and intake air leak.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF652Y
SEF058Y
SEF203X Mass air flow sensor
harness connector
Air cleaner
DTC P0171 FUEL INJECTION SYSTEM FUNCTION
(LEAN SIDE)SR20DE
On Board Diagnosis Logic
EC-212
On Board Diagnosis LogicNCEC0192With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensor 1 (front).
The ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as a fuel injection system malfunction and lights up the MI (2 trip detection logic).
Sensor Input Signal to ECMECM func-
tionActuator
Heated oxygen sensor 1 (front)Density of oxygen in exhaust gas
(Mixture ratio feedback signal)Fuel injec-
tion & mix-
ture ratio
controlInjectors
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0172
0172IFuel injection system does not operate properly.
IThe amount of mixture ratio compensation is too large.
(The mixture ratio is too rich.)IHeated oxygen sensor 1 (front)
IInjectors
IExhaust gas leaks
IIncorrect fuel pressure
IMass air flow sensor
DTC Confirmation ProcedureNCEC0193NOTE:
If ªDTC Confirmation Procedure º has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
IAlways perform at a temperature above þ10ÉC (14ÉF).
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds.
3) Turn ignition switch ªONº and select ªSELF-LEARN CON-
TROLº in ªWORK SUPPORTº mode with CONSULT-II.
4) Clear the self-learning control coefficient by touching ªCLEARº.
5) Select ªDATA MONITORº mode with CONSULT-II.
6) Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0172 should be detected at this stage, if a
malfunction exists. If so, go to ªDiagnostic Procedureº, EC-SR-
221.
7) If it is difficult to start engine at step 6, the fuel injection sys-
tem has a malfunction.
8) Crank engine while depressing accelerator pedal. If engine
starts, go to ªDiagnostic Procedureº, EC-SR-221. If engine
does not start, remove ignition plugs and check for fouling, etc.
SEF652Y
SEF058Y
DTC P0172 FUEL INJECTION SYSTEM FUNCTION
(RICH SIDE)SR20DE
On Board Diagnosis Logic
EC-218
On Board Diagnosis LogicNCEC0202If a misfire occurs, the engine speed will fluctuate. If the fluctuation is detected by the crankshaft position sen-
sor (OBD), the misfire is diagnosed.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (OBD) Engine speed On board diagnosis of misfire
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to
overheating, the MI will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MI will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MI will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MI will remain on.
If another misfire condition occurs that can damage the TWC, the MI will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect exhaust vehicle emissions), the MI will
only light when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP
sensor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0300
0300IMultiple cylinders misfire.IImproper spark plug
IInsufficient compression
IIncorrect fuel pressure
IThe injector circuit is open or shorted
IInjectors
IIntake air leak
IThe ignition secondary circuit is open or
shorted
ILack of fuel
IHeated oxygen sensor 1 (front)
IDrive plate/Flywheel
IIncorrect distributor rotor P0301
0301INo. 1 cylinder misfires.
P0302
0302INo. 2 cylinder misfires.
P0303
0303INo. 3 cylinder misfires.
P0304
0304INo. 4 cylinder misfires.
DTC Confirmation ProcedureNCEC0203CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
IAlways perform at a temperature above þ10ÉC (14ÉF).
With CONSULT-II
1) Turn ignition switch ªONº, and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and warm it up to normal operating temperature.
3) Turn ignition switch ªOFFº and wait at least 9 seconds.
4) Start engine again and drive at 1,500 - 3,000 rpm for at least
3 minutes.
Hold the accelerator pedal as steady as possible.
NOTE:
Refer to the freeze frame data for the test driving conditions.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-SR-225.
With GST
Follow the procedure ªWith CONSULT-IIº above.
NEF068A
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIRESR20DE
On Board Diagnosis Logic
EC-224
Component DescriptionNCEC0206The knock sensor is attached to the cylinder block. It senses
engine knocking using a piezoelectric element. A knocking vibration
from the cylinder block is sensed as vibrational pressure. This
pressure is converted into a voltage signal and sent to the ECM.
Freeze frame data will not be stored in the ECM for the knock
sensor. The MI will not light for knock sensor malfunction. The
knock sensor has one trip detection logic.
ECM Terminals and Reference ValueNCEC0207Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
81 W Knock sensor[Engine is running]
IIdle speed2.0 - 3.0V
On Board Diagnosis LogicNCEC0208
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0325
0325IAn excessively low or high voltage from the knock sen-
sor is sent to ECM.IHarness or connectors
(The knock sensor circuit is open or shorted.)
IKnock sensor
DTC Confirmation ProcedureNCEC0209NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 10V at idle.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and run it for at least 5 seconds at idle speed.
3) If DTC is detected, go to ªDiagnostic Procedureº, EC-SR-232.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF598K
NEF068A
DTC P0325 KNOCK SENSOR (KS)SR20DE
Component Description
EC-230
Component DescriptionNCEC0220The camshaft position sensor is a basic component of the engine
control system. It monitors engine speed and piston position.
These input signals to the engine control system are used to con-
trol fuel injection, ignition timing and other functions.
The camshaft position sensor has a rotor plate and a wave-form-
ing circuit. The rotor plate has 360 slits for a 1É (POS) signal and
4 slits for a 180É (REF) signal. The wave-forming circuit consists
of Light Emitting Diodes (LED) and photo diodes.
The rotor plate is positioned between the LED and the photo diode.
The LED transmits light to the photo diode. As the rotor plate turns,
the slits cut the light to generate rough-shaped pulses. These
pulses are converted into on-off signals by the wave-forming circuit
and sent to the ECM.
The distributor is not repairable and must be replaced as an
assembly except distributor cap and rotor head.
ECM Terminals and Reference ValueNCEC0221Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
66*1 L
Camshaft position sen-
sor (Reference signal)[Engine is running]
IWarm-up condition
IIdle speed0.1 - 0.4V
SEF006W
75 L[Engine is running]
IEngine speed is 2,000 rpm0.1 - 0.4V
SEF007W
*1: Models before VIN - P11U0548750
SEF998R Rotor head
Sealed
cover
Ignition coil
with power
transistor Light
emitting
diode
Photo diode
SEF853B 180É signal slit for No. 1 cylinder
1É signal slit
180É signal slit
Rotor plate
DTC P0340 CAMSHAFT POSITION SENSOR (CMPS)SR20DE
Component Description
EC-239
4 CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-I
1. Reconnect the ECM harness connector and IACV-AAC valve harness connector.
2. Disconnect vacuum hose connected to air control valve (Power steering) at intake air duct.
3. Start and let it idle.
4. Check vacuum hose for vacuum existence.
SEF969X
Vacuum slightly exists or does not exist.
OK or NG
OK©GO TO 5.
NG©Replace air control valve (Power steering).
5 CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-II
Check the vacuum hose for vacuum existence when steering wheel is turned.
SEF969X
Vacuum should exist.
OK or NG
OK©GO TO 8.
NG©GO TO 6.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Diagnostic Procedure (Cont'd)
EC-267
Component DescriptionNCEC0287A closed throttle position switch and wide open throttle position
switch are built into the throttle position sensor unit. The wide open
throttle position switch is used only for CVT control.
When the throttle valve is in the closed position, the closed throttle
position switch sends a voltage signal to the ECM. The ECM only
uses this signal to open or close the EVAP canister purge control
valve when the throttle position sensor is malfunctioning.
CONSULT-II Reference Value in Data Monitor
Mode
NFEC0257Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CLSD THL/P SEIEngine: IdleThrottle valve: Idle position ON
Throttle valve: Slightly open OFF
ECM Terminals and Reference ValueNCEC0288Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
40 YThrottle position switch
(Closed position)[Engine is running]
IAccelerator pedal releasedBATTERY VOLTAGE
(11 - 14V)
[Ignition switch ªONº]
IAccelerator pedal depressedApproximately 0V
On Board Diagnosis LogicNCEC0289
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0510
0510IBattery voltage from the closed throttle position switch is
sent to ECM with the throttle valve opened.IHarness or connectors
(The closed throttle position switch circuit is
shorted.)
IClosed throttle position switch
IThrottle position sensor
SEF505V
Throttle position switch
built into throttle
position sensor
Throttle position
switch connector
Throttle position
sensor connector
DTC P0510 CLOSED THROTTLE POSITION SWITCH
(IF SO EQUIPPED)SR20DE
Component Description
EC-271