12 CHECK RADIATOR CAP
Apply pressure to cap with a tester.
SLC755A
Radiator cap relief pressure:
59 - 98 kPa (0.59 - 0.98 bar, 0.6 - 1.0 kg/cm2,9-14psi)
OK or NG
OK©GO TO 13.
NG©Replace radiator cap.
13 CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve lift.
SLC343
Valve opening temperature:
82ÉC (180ÉF) [standard]
Valve lift:
More than 8 mm/95ÉC (0.31 in/203ÉF)
3. Check if valve is closed at 5ÉC (9ÉF) below valve opening temperature.
For details, refer to LC section (ªThermostatº).
OK or NG
OK©GO TO 14.
NG©Replace thermostat
14 CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to ªCOMPONENT INSPECTIONº, EC-167.
OK or NG
OK©GO TO 15.
NG©Replace engine coolant temperature sensor.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-343
Main 12 Causes of Overheating=NJEC0492
Engine Step Inspection item Equipment Standard Reference page
OFF 1+Blocked radiator
+Blocked condenser
+Blocked radiator grille
+Blocked bumper+Visual No blocking Ð
2+Coolant mixture+Coolant tester 50 - 50% coolant mixture See MA-20, ªRECOM-
MENDED FLUIDS AND
LUBRICANTSº.
3+Coolant level+Visual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee LC-17, ªChanging
Engine Coolantº.
4+Radiator cap+Pressure tester 59 - 98 kPa
(0.59 - 0.98 bar, 0.6 - 1.0
kg/cm
2,9-14psi) (Limit)See LC-10, ªSystem
Checkº.
ON*
25+Coolant leaks+Visual No leaks See LC-10, ªSystem
Checkº.
ON*
26+Thermostat+Touch the upper and
lower radiator hosesBoth hoses should be
hotSee LC-15, ªThermostatº
and LC-16, ªRadiatorº.
ON*
17+Cooling fan+CONSULT-II Operating See ªTROUBLE DIAG-
NOSIS FOR OVER-
HEATº (EC-334).
OFF 8+Combustion gas leak+Color checker chemi-
cal tester 4 Gas ana-
lyzerNegative Ð
ON*
39+Coolant temperature
gauge+Visual Gauge less than 3/4
when drivingÐ
+Coolant overflow to
reservoir tank+Visual No overflow during driv-
ing and idlingSee LC-17, ªChanging
Engine Coolantº.
OFF*
410+Coolant return from
reservoir tank to radia-
tor+Visual Should be initial level in
reservoir tankSee LC-18, ªRefilling
Engine Coolantº.
OFF 11+Cylinder head+Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See EM-36, ªInspectionº,
ªCYLINDER HEADº.
12+Cylinder block and
pistons+Visual No scuffing on cylinder
walls or pistonSee EM-54, ªInspectionº,
ªCYLINDER BLOCKº.
*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to LC-23, ª OVERHEATING CAUSE ANALYSISº.
SEF745U
Component InspectionNJEC0493COOLING FAN RELAYNJEC0493S01Check continuity between terminals 3 and 5, 6 and 7.
Conditions Continuity
12V direct current supply between terminals 1 and
2Ye s
No current supply No
If NG, replace relay.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Main 12 Causes of Overheating
EC-345
SEF174Y
PROCEDURE FOR MALFUNCTION A=NJEC0344S01With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Verify that ªCOOLAN TEMP/Sº is less than 50ÉC (122ÉF).
If the engine coolant temperature is above the range, cool
the engine down.
4) Start engine and let it idle for at least 5 seconds.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-351.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF200Y
PROCEDURE FOR MALFUNCTION BNJEC0344S02CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
Always perform the test at a temperature above þ10ÉC (14ÉF).
With CONSULT-II
1) Start engine and warm it up to above 80ÉC (176ÉF).
2) Select ªEGR VOL CONT/Vº in ªACTIVE TESTº mode with
CONSULT.
3) Hold engine speed at 1,500 rpm.
4) Touch ªQuº and set the EGR volume control valve opening to
50 step and check EGR TEMP SEN.
EGR TEMP SEN should decrease to less than 1.0V.
If the check result is NG, go to ªDIAGNOSTIC PROCEDUREº,
EC-351.
If the check result is OK, go to the following step.
SEF201Y
5) Turn ignition switch ªOFFº and wait at least 9 seconds.
6) Start engine and maintain the following conditions for at least
5 consecutive seconds.
ENG SPEED Above 2,400 rpm
VHCL SPEED SE Above 90 km/h (56 MPH) or more
B/FUEL SCHDL 4.0 - 4.8 msec
Selector lever Suitable position
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-351.
DTC P1401 EGR TEMPERATURE SENSOR (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-348
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
SEF947X
With GST
1) Turn ignition switch ªONº and select ªMODE 1º with GST.
2) Check that engine coolant temperature is within the range of
þ10 to 40ÉC (14 to 104ÉF).
3) Check that voltage between ECM terminal 72 (EGR tempera-
ture sensor signal) and ground is less than 4.8V.
4) Start engine and let it idle for at least 45 seconds.
5) Stop engine.
6) Perform from step 1 to 4.
7) Select ªMODE 3º with GST.
8) If DTC is detected, go to ªDiagnostic Procedureº, EC-358.
+When using GST, ªDTC Confirmation Procedureº should
be performed twice as much as when using CONSULT-II
because GST cannot display MODE 7 (1st trip DTC) con-
cerning this diagnosis. Therefore, using CONSULT-II is
recommended.
DTC P1402 EGR FUNCTION (OPEN) (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-356
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