DescriptionNJEC1265The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
+B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
+A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)
+MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNJEC1266+Vehicle driven distance: More than 5,000 km (3,017 miles)
+Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2, 14.25 - 15.12 psi)
+Atmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
+Engine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
+Transmission: Warmed-up*1
+Electrical load: Not applied*2
+Engine speed: Idle
*1: For A/T or CVT models, after the engine is warmed up to normal operating temperature, drive vehicle until
ªFLUID TEMP SEº (A/T or CVT fluid temperature sensor signal) indicates less than 0.9V. For M/T models, drive
vehicle for 5 minutes after the engine is warmed up to normal operating temperature.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNJEC1267NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-98.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-141.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUEQG
Description
EC-140
DescriptionNJEC0045Intermittent incidents (I/I) may occur. In many cases, the problem resolves itself (the part or circuit function
returns to normal without intervention). It is important to realize that the symptoms described in the custom-
er's complaint often do not recur on DTC (1st trip) visits. Realize also that the most frequent cause of I/I
occurrences is poor electrical connections. Because of this, the conditions under which the incident occurred
may not be clear. Therefore, circuit checks made as part of the standard diagnostic procedure may not indi-
cate the specific problem area.
COMMON I/I REPORT SITUATIONSNJEC0045S01
STEP in Work Flow Situation
IIThe CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than ª0º or
ª1tº.
III The symptom described by the customer does not recur.
IV (1st trip) DTC data does not appear during the DTC Confirmation Procedure.
VI The Diagnostic Procedure for PXXXX does not indicate the problem area.
Diagnostic ProcedureNJEC0046
1 INSPECTION START
Erase (1st trip) DTCs. Refer to ªHow to Erase Emission-related Diagnostic Informationº, EC-68, EC-71.
©GO TO 2.
2 CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection. Refer to GI-27, ªGROUND INSPECTIONº.
OK or NG
OK©GO TO 3.
NG©Repair or replace.
3 SEARCH FOR ELECTRICAL INCIDENT
Perform GI-22, ªIncident Simulation Testsº.
OK or NG
OK©INSPECTION END
NG©Repair or replace.
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTQG
Description
EC-144
SEC500C
Component DescriptionNJEC0066The intake air temperature sensor is built into the mass air flow
sensor. The sensor detects intake air temperature and transmits a
signal to the ECM.
The temperature sensing unit uses a thermistor which is sensitive
to the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.
Intake air temperature
ÉC (ÉF)Voltage*
VResistance
kW
25 (77) 3.3 1.9 - 2.1
80 (176) 1.28 0.31 - 0.37
*: These data are reference values and are measured between ECM terminal 64
(Intake air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
On Board Diagnosis LogicNJEC0067
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0110
0110An excessively low or high voltage from the sensor is sent
to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Intake air temperature sensor
DTC Confirmation ProcedureNJEC0068NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
DTC P0110 INTAKE AIR TEMPERATURE SENSORQG
Component Description
EC-158
SEF594K
Component DescriptionNJEC0072The engine coolant temperature sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the
engine coolant temperature input. The sensor uses a thermistor
which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
SEF012P
Engine coolant temperature
ÉC (ÉF)Voltage*
VResistance
kW
þ10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
*: These data are reference values and are measured between ECM terminal 70
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0073
MONITOR ITEM CONDITION SPECIFICATION
COOLAN TEMP/S+Engine: After warming up More than 70ÉC (158ÉF)
On Board Diagnosis LogicNJEC0074
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0115
0115+An excessively high or low voltage from the sensor is
sent to ECM.*+Harness or connectors
(The sensor circuit is open or shorted.)
+Engine coolant temperature sensor
*: When this malfunction is detected, the ECM enters fail-safe mode and the MI lights up.
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
(CIRCUIT)
QG
Component Description
EC-163
DescriptionNJEC0227SYSTEM DESCRIPTIONNJEC0227S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
EGR vol-
ume controlEGR volume control valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Vehicle speed sensor Vehicle speed
Battery Battery voltage
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Electrical load Electrical load signal
PNP switch Park/Neutral position signal
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in the
EGR volume control valve changes to control the flow rate. A
built-in step motor moves the valve in steps corresponding to the
ECM output pulses. The opening of the valve varies for optimum
engine control. The optimum value stored in the ECM is determined
by considering various engine conditions. The EGR volume control
valve remains close under the following conditions.
+Low engine coolant temperature
+Engine starting
+High-speed engine operation
+Extremely light load engine operation
+Engine idling
+Excessively high engine coolant temperature
+Wide open throttle
+Mass air flow sensor malfunction
+Low battery voltage
SEF551W
DTC P0400 EGR FUNCTION (CLOSED) (WHERE FITTED)QG
Description
EC-285
DescriptionNJEC0504SYSTEM DESCRIPTIONNJEC0504S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
EGR vol-
ume controlEGR volume control valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Vehicle speed sensor Vehicle speed
Battery Battery voltage
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Electrical load Electrical load signal
PNP switch Park/Neutral position signal
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in the
EGR volume control valve changes to control the flow rate. A
built-in step motor moves the valve in steps corresponding to the
ECM output pulses. The opening of the valve varies for optimum
engine control. The optimum value stored in the ECM is determined
by considering various engine conditions. The EGR volume control
valve remains close under the following conditions.
+Low engine coolant temperature
+Engine starting
+High-speed engine operation
+Extremely light load engine operation
+Engine idling
+Excessively high engine coolant temperature
+Wide open throttle
+Mass air flow sensor malfunction
+Low battery voltage
SEF551W
DTC P0403 EGR VOLUME CONTROL VALVE (CIRCUIT)
(WHERE FITTED)
QG
Description
EC-293
DescriptionNJEC0279SYSTEM DESCRIPTIONNJEC0279S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed
Idle air
controlIACV-AAC valve Camshaft position sensor (PHASE) Engine speed and cylinder number
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
PNP switch Park/Neutral position
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Battery Battery voltage
Vehicle speed sensor Vehicle speed
Cooling fan Cooling fan operation
Electrical load Electrical load signal
This system automatically controls engine idle speed to a specified
level. Idle speed is controlled through fine adjustment of the
amount of air which by-passes the throttle valve via IACV-AAC
valve. The IACV-AAC valve changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actu-
ated by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output sig-
nals. One step of IACV-AAC valve movement causes the respec-
tive opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the valve is
varied to allow for optimum control of the engine idling speed. The
crankshaft position sensor (POS) detects the actual engine speed
and sends a signal to the ECM. The ECM then controls the step
position of the IACV-AAC valve so that engine speed coincides with
the target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The opti-
mum value stored in the ECM is determined by taking into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering, cool-
ing fan operation and electrical load).
SEF937W
COMPONENT DESCRIPTIONNJEC0279S02IACV-AAC ValveNJEC0279S0202The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in sequence. Each time the IACV-AAC
valve opens or closes to change the auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
QG
Description
EC-313
SEC500C
Component DescriptionNJEC1737The intake air temperature sensor is built into the mass air flow
sensor. The sensor detects intake air temperature and transmits a
signal to the ECM.
The temperature sensing unit uses a thermistor which is sensitive
to the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.
Intake air temperature
ÉC (ÉF)Voltage*
VResistance
kW
25 (77) 3.3 1.9 - 2.1
80 (176) 1.28 0.31 - 0.37
*: These data are reference values and are measured between ECM terminal 64
(Intake air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
INTAKE AIR TEMPERATURE SENSORQG
Component Description
EC-369