Page 1137 of 2898
9 CHECK COOLING FAN MOTORS-1 AND -2
Refer to ªComponent Inspectionº, EC-416.
OK or NG
OK©GO TO 10.
NG©Replace cooling fan motors.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-177.
©INSPECTION END
11 CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the pressure drops.
Testing pressure: 157 kPa (1.57 bar, 1.6 kg/cm2, 23 psi)
CAUTION:
Higher than the specified pressure may cause radiator damage.
SLC754A
Pressure should not drop.
OK or NG
OK©GO TO 12.
NG©Check the following for leak
+Hose
+Radiator
+Water pump
Refer to LC-14, ªWater Pumpº.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-413
Page 1138 of 2898
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-206.
OK or NG
OK©GO TO 15.
NG©Replace engine coolant temperature sensor.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-414
Page 1139 of 2898
15 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-416.
©INSPECTION END
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Diagnostic Procedure (Cont'd)
EC-415
Page 1140 of 2898

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-16, ªRECOM-
MENDED FLUIDS AND
LUBRICANTSº.
3+Coolant level+Visual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee LC-18, 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-406).
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-18, ªChanging
Engine Coolantº.
OFF*
410+Coolant return from
reservoir tank to radia-
tor+Visual Should be initial level in
reservoir tankSee LC-19, ªRefilling
Engine Coolantº.
OFF 11+Cylinder head+Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See EM-37, ªInspectionº,
ªCYLINDER HEADº.
12+Cylinder block and
pistons+Visual No scuffing on cylinder
walls or pistonSee EM-56, 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-24, 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-416
Page 1141 of 2898
SEF610Y
COOLING FAN MOTORS-1 AND -2NJEC0493S021. Disconnect cooling fan motor harness connectors.
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Terminals
(+) (þ)
Cooling fan motor 2 1
Cooling fan motor should operate.
If NG, replace cooling fan motor.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG
Component Inspection (Cont'd)
EC-417
Page 1142 of 2898

SEF599K
Component DescriptionNJEC0342The EGR temperature sensor detects temperature changes in the
EGR passageway. When the EGR volume control valve opens, hot
exhaust gases flow, and the temperature in the passageway
changes. The EGR temperature sensor is a thermistor that modi-
fies a voltage signal sent from the ECM. This modified signal then
returns to the ECM as an input signal. As the temperature
increases, EGR temperature sensor resistance decreases. This
sensor is not used to control the engine system.
It is used only for the on board diagnosis.
SEF068X
EGR temperature
ÉC (ÉF)Voltage*
VResistance
MW
0 (32) 4.56 0.62 - 1.05
50 (122) 2.25 0.065 - 0.094
100 (212) 0.59 0.011 - 0.015
*: These data are reference values and are measured between ECM terminal 72
(EGR temperature sensor) and ground.
When EGR system is operating.
Voltage: 0 - 1.5V
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 LogicNJEC0343
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P1401
1401A) An excessively low voltage from the EGR tempera-
ture sensor is sent to ECM even when engine cool-
ant temperature is low.+Harness or connectors
(The EGR temperature sensor circuit is shorted.)
+EGR temperature sensor
+Malfunction of EGR function
B) An excessively high voltage from the EGR tempera-
ture sensor is sent to ECM even when engine cool-
ant temperature is high.+Harness or connectors
(The EGR temperature sensor circuit is open.)
+EGR temperature sensor
+Malfunction of EGR function
DTC Confirmation ProcedureNJEC0344Perform ªPROCEDURE FOR MALFUNCTION Aº first. If 1st trip
DTC cannot be confirmed, perform ªPROCEDURE FOR MAL-
FUNCTION Bº.
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.
DTC P1401 EGR TEMPERATURE SENSOR (WHERE FITTED)QG
Component Description
EC-418
Page 1143 of 2898

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-423.
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-423.
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-423.
DTC P1401 EGR TEMPERATURE SENSOR (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-419
Page 1144 of 2898
With GST
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº and wait at least 9 seconds, then
turn ªONº.
3) Select ªMODE 1º with GST and maintain the following condi-
tions for at least 5 consecutive seconds.
Engine speed Above 2,400 rpm
Vehicle speed Above 90 km/h (56 MPH)
Selector lever 4th or 5th
4) Select ªMODE 7º with GST
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-423.
DTC P1401 EGR TEMPERATURE SENSOR (WHERE FITTED)QG
DTC Confirmation Procedure (Cont'd)
EC-420