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
DescriptionNJEC0349SYSTEM DESCRIPTIONNJEC0349S01
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
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.
+Extremely light load engine operation
+Mass air flow sensor malfunction
+Engine idling
+Low engine coolant temperature
+Excessively high engine coolant temperature
+High-speed engine operation
+Wide open throttle
+Low battery voltage
+Engine starting
SEF551W
DTC P1402 EGR FUNCTION (OPEN) (WHERE FITTED)QG
Description
EC-353
SEF552W
COMPONENT DESCRIPTIONNJEC0349S02EGR Volume Control ValveNJEC0349S0201The EGR volume control valve uses a step motor to control the flow
rate of EGR from exhaust manifold. This motor has four winding
phases. It operates according to the output pulse signal of the
ECM. Two windings are turned ON and OFF in sequence. Each
time an ON pulse is issued, the valve opens or closes, changing
the flow rate. When no change in the flow rate 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.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0539Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
EGR TEMP SEN+Engine: After warming up Less than 4.5V
EGR VOL CON/V+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: ªNº
+No-loadIdle 0 step
Revving engine up to 3,000 rpm
quickly10 - 55 step
ECM Terminals and Reference ValueNJEC0540Specification data are reference values, and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
8
9
17
18SB
W/B
R/Y
BR/REGR volume control valve[Engine is running.]
+Warm-up condition
+Idle speed0 - 14V
58 B Sensor's ground[Engine is running.]
+Warm-up condition
+Idle speed0V
72 P/B EGR temperature sensor[Engine is running.]
+Warm-up condition
+Idle speedLess than 4.5V
[Engine is running.]
+Warm-up condition
+EGR system is operating.0 - 1.0V
SEF073P
On Board Diagnosis LogicNJEC0350If EGR temperature sensor detects EGR flow under the condition
that does not call for EGR, a high-flow malfunction is diagnosed.
NOTE:
Diagnosis for this DTC will occur when engine coolant temperature
is below 50 to 60ÉC (122 to 140ÉF). Therefore, it will be better to
turn ignition switch ªONº (start engine) at the engine coolant tem-
perature below 30ÉC (86ÉF) when starting DTC confirmation pro-
cedure.
DTC P1402 EGR FUNCTION (OPEN) (WHERE FITTED)QG
Description (Cont'd)
EC-354
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P1402
1402+EGR flow is detected under conditions that do not call for
EGR.+Harness or connectors
(The valve circuit is open or shorted.)
+EGR volume control valve leaking or stuck open
+EGR temperature sensor
SEF202Y
SEF851Y
SEF852Y
SEF236Y
DTC Confirmation ProcedureNJEC0351NOTE:
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:
+Always perform at a temperature above þ10ÉC (14ÉF).
+Engine coolant temperature and EGR temperature must
be verified in ªDATA MONITORº mode with CONSULT-II
before starting DTC WORK SUPPORT test. If it is out of
range below, the test cannot be conducted.
COOLAN TEMP/S: þ10 to 40ÉC (14 to 104ÉF)*
EGR TEMP SEN: Less than 4.8V
If the values are out of the ranges indicated above, park
the vehicle in a cool place and allow the engine tempera-
ture to stabilize. Do not attempt to reduce the engine cool-
ant or EGR temperature with a fan or means other than
ambient air. Doing so may produce an inaccurate diagnos-
tic result.
*: Although CONSULT-II screen displays ªþ10 to 40ÉC (14 to
104ÉF)º as a range of engine coolant temperature, ignore it.
With CONSULT-II
1) Turn ignition switch ªOFFº and wait at least 9 seconds, then
turn ignition switch ªONº.
2) Select ªEGR SYSTEM P1402º of ªEGR SYSTEMº in ªDTC
WORK SUPPORTº mode with CONSULT-II.
3) Touch ªSTARTº. Follow instruction of CONSULT-II.
4) Start engine and let it idle until ªTESTINGº on CONSULT-II
screen is turned to ªCOMPLETEDº. (It will take 45 seconds or
more.)
If ªTESTINGº is not displayed after 5 minutes, turn ignition
ªOFFº and cool the engine coolant temperature to the
range of þ10 to 40ÉC (14 to 104ÉF). Retry from step 1.
5) Make sure that ªOKº is displayed after touching ªSELF-DIAG
RESULTSº. If ªNGº is displayed, refer to ªDiagnostic
Procedureº, EC-358.
DTC P1402 EGR FUNCTION (OPEN) (WHERE FITTED)QG
On Board Diagnosis Logic (Cont'd)
EC-355
SEF740W
Component DescriptionNJEC0424When the gear position is ªPº (A/T models only) or ªNº, park/neutral
position (PNP) switch is ªONº.
ECM detects the park/neutral position when continuity with ground
exists.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0425Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
P/N POSI SW+Ignition switch: ONShift lever: ªPº or ªNº ON
Except above OFF
ECM Terminals and Reference ValueNJEC0426Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
42 G/OR PNP switch[Ignition switch ªONº]
+Gear position is ªNeutral positionº (M/T models)
+Gear position is ªNº or ªPº (A/T models)Approximately 0V
[Ignition switch ªONº]
+Except the above gear positionA/T models
BATTERY VOLTAGE
(11 - 14V)
M/T models
Approximately 5V
On Board Diagnosis LogicNJEC0427
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P1706
1706+The signal of the PNP switch is not changed in the pro-
cess of engine starting and driving.+Harness or connectors
(The PNP switch circuit is open or shorted.)
+PNP switch
DTC Confirmation ProcedureNJEC0428CAUTION:
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.
With CONSULT-II
1) Turn ignition switch ªONº.
DTC P1706 PARK/NEUTRAL POSITION (PNP) SWITCHQG
Component Description
EC-364
DescriptionNJEC1746SYSTEM DESCRIPTIONNJEC1746S01
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
EGR VOLUME CONTROL SYSTEM (WHERE FITTED)QG
Description
EC-400
Fuel Injection Control System
DESCRIPTIONNJEC0612System DescriptionNJEC0612S01Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control,
the amount of fuel injected is compensated to improve engine performance.
Pulse signals are exchanged between ECM and electronic control fuel injection pump (control unit is built-in).
The fuel injection pump control unit performs duty control on the spill valve (built into the fuel injection pump)
according to the input signals to compensate the amount of fuel injected to the preset value.
Start ControlNJEC0612S02Input/Output Signal ChartNJEC0612S0201
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (start
control)Electronic control fuel
injection pump Crankshaft position sensor (TDC) Engine speed
Ignition switch Start signal
SEF648S
When the ECM receives a start signal from the ignition switch, the ECM adapts the fuel injection system for
the start control. The amount of fuel injected at engine starting is a preset program value in the ECM. The
program is determined by the engine speed and engine coolant temperature.
For better startability under cool engine conditions, the lower the coolant temperature becomes, the greater
the amount of fuel injected. The ECM ends the start control when the engine speed reaches the specific value,
and shifts the control to the normal or idle control.
Idle ControlNJEC0612S03Input/Output Signal ChartNJEC0612S0301
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (Idle con-
trol)Electronic control fuel
injection pump Crankshaft position sensor (TDC) Engine speed
Battery Battery voltage
Accelerator position switch Idle position
Vehicle speed sensor Vehicle speed
Air conditioner switch Air conditioner signal
When the ECM determines that the engine speed is at idle, the fuel injection system is adapted for the idle
control. The ECM regulates the amount of fuel injected corresponding to changes in load applied to the engine
to keep engine speed constant. The ECM also provides the system with a fast idle control in response to the
engine coolant temperature signal.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONYD
Fuel Injection Control System
EC-505