
Description
SYSTEM DESCRIPTION
Sensor Input signal to ECM ECM function Actuator
Engine coolant temperature
sensorEngine coolant temperature
Cooling fan control Cooling fan relay
Air conditioner switch Air conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, air condi-
tioner ON signal.
On Board Diagnosis Logic
This diagnosis continuously monitors the engine coolant temperature.
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
DTC Malfunction is detected when ... Check Items (Possible Cause)
P1217
0208ICooling fan does not operate properly (Overheat).
ICooling fan system does not operate properly (Over-
heat).
IEngine coolant was not added to the system using
the proper filling method.IHarness or connectors
(The cooling fan circuit is open or shorted.)
ICooling fan
IRadiator hose
IRadiator
IRadiator cap
IWater pump
IThermostat
IEngine coolant temperature sensor
For more information, refer to ªMAIN 12 CAUSES OF
OVERHEATINGº, EC-425.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the LC
section, ªChanging Engine Coolantº. Also, replace the engine oil.
1) Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to
use coolant with the proper mixture ratio. Refer to MA section, ªEngine Coolant Mixture Ratioº.
2) After refilling coolant, run engine to ensure that no water-flow noise is emitted.
DTC P1217 OVER HEATTD27Ti
EC-418

Overall Function Check
Use this procedure to check the overall function of the cooling fan.
During this check, a DTC might not be confirmed.
WARNING:
Never remove the radiator cap when the engine is hot. Serious
burns could be caused by high pressure fluid escaping from
the radiator.
Wrap a thick cloth around the cap. Carefully remove the cap
by turning it a quarter turn to allow built-up pressure to
escape. Then turn the cap all the way off.
WITH CONSULT-II
1) Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-421.
2) Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-421.
3) Turn ignition switch ªONº.
4) Perform ªCOOLING FANº in ªACTIVE TESTº mode with CON-
SULT-II and make sure that cooling fans operate.
If NG, go to ªDiagnostic Procedureº, EC-421.
WITHOUT CONSULT-II
1) Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-421.
2) Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-421.
3) Start engine.
Be careful not to overheat engine.
4) Set temperature control lever to full cold position.
5) Turn air conditioner switch ªONº.
6) Turn blower fan switch ªONº.
7) Run engine at idle for a few minutes with air conditioner oper-
ating.
Be careful not to overheat engine.
8) Make sure that cooling fans operate at low speed.
9) Turn ignition switch ªOFFº.
10) Turn air conditioner switch and blower fan switch ªOFFº.
11) Disconnect engine coolant temperature sensor harness con-
nector.
12) Connect 150Wresistor to engine coolant temperature sensor
harness connector.
13) Start engine and make sure that cooling fans operate at higher
speed than low speed.
Be careful not to overheat engine.
14) If NG, go to ªDiagnostic Procedureº, EC-421.
AEC640
SEF111X
SEC163BA
MEC475B
DTC P1217 OVER HEATTD27Ti
EC-419

Diagnostic Procedure
INSPECTION START
CHECK OVERALL FUNCTION.
With CONSULT-II
1. Turn ignition switch ªONº.
2. Perform ªCOOLING FANº in ªACTIVE
TESTº mode with CONSULT-II.
3. Make sure that cooling fan operate.
Without CONSULT-II
1. Start engine and let it idle.
2. Set temperature lever at full cold posi-
tion.
3. Turn air conditioner switch ªONº.
4. Turn blower fan switch ªONº.
5. Make sure that cooling fan operate.
NG
EOK
Go to ªqCº, EC-424.
CHECK COOLING FAN RELAY POWER
SUPPLY CIRCUIT.
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan relay.
3. Check voltage between cooling fan
relay terminalq
3and ground with
CONSULT-II or tester.
Voltage: Battery voltage
OK
ENG
Check the following.
I30A fuse
IHarness for open or
short between cooling
fan relay and battery
If NG, repair or replace
harness or fuse.
CHECK COOLING FAN MOTOR AND
CONDENSER CIRCUIT.
1. Disconnect cooling fan relay harness
connector, cooling fan motor harness
connector and condenser harness con-
nector.
2. Check continuity as follows. Refer to
wiring diagram.
OK
ENG
Check the following.
IHarness connectors
M785,F67
IHarness for open or
short between cooling
fan relay and cooling fan
motor
IHarness for open or
short between cooling
fan relay and condenser
If NG, repair harness or
connectors.
qA
Cooling fan relay terminalq5and cooling fan motor terminal
q1Continuity
should
exist.
Cooling fan relay terminalq
5and condenser terminalq1
SEF646X
SEC163BA
MEC940D
H
H
H
H
DTC P1217 OVER HEATTD27Ti
EC-421

qc
CHECK COOLING SYSTEM FOR LEAK.
Apply pressure to the cooling system with
a tester, and check if the pressure drops.
Testing pressure:
157 kPa (1.6 kg/cm
2, 23 psi)
Pressure should not drop.
CAUTION:
Higher than the specified pressure may
cause radiator damage.
OK
ENG
Check the following for
leak.
IHose
IRadiator
IWater pump
Refer to LC section (ªWater
Pumpº).
CHECK RADIATOR CAP.
Apply pressure to cap with a tester.
Radiator cap relief pressure:
78 - 98 kPa (0.8 - 1.0 kg/cm
2,11-14
psi)
OK
ENG
Replace radiator cap.
CHECK THERMOSTAT.
1. Check valve seating condition at normal
room temperatures.
It should seat tightly.
2. Check valve opening temperature and
valve lift.
Valve opening temperature:
76.5ÉC (170ÉF) [standard]
Valve lift:
More than 10 mm/90ÉC
(0.39 in/194ÉF)
3. Check if valve is closed at 5ÉC (9ÉF)
below valve opening temperature.
For details, refer to LC section (ªThermo-
statº).
OK
ENG
Replace thermostat
Check engine coolant temperature sensor.
Refer to ªCOMPONENT INSPECTIONº,
EC-426.
OK
ENG
Replace engine coolant
temperature sensor.
If the cause can not be isolated, go to
ªMAIN 12 CAUSES OF OVERHEATINGº
on EC-425.
INSPECTION END
SLC754A
SLC755A
SLC343
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DTC P1217 OVER HEATTD27Ti
Diagnostic Procedure (Cont'd)
EC-424

Main 12 Causes of Overheating
Engine Step Inspection item Equipment Condition Reference page
OFF1IBlocked radiator
IBlocked radiator grille
IBlocked bumperIVisual No blocking Ð
2ICoolant mixtureICoolant tester 50 - 50% coolant mixtureSee MA section, ªRECOM-
MENDED FLUIDS AND
LUBRICANTSº.
3ICoolant levelIVisualCoolant up to MAX level in
reservoir tank and radiator
filler neckSee LC section, ªChanging
Engine Coolantº.
4IRadiator capIPressure tester78 - 98 kPa (0.78 - 0.98
bar, 0.8 - 1.0 kg/cm
2,11-14
psi)See LC section, ªSystem
Checkº.
ON*
25ICoolant leaksIVisual No leaksSee LC section, ªSystem
Checkº.
ON*
26IThermostatITouch the upper and
lower radiator hosesBoth hoses should be hotSee LC section, ªThermo-
statº and ªRadiatorº.
ON*
17ICooling fanICONSULT-II OperatingSee Trouble Diagnosis for
DTC P1217, EC-418.
OFF 8ICombustion gas leakIColor checker chemical
tester 4 Gas analyzerNegative Ð
ON*
39ICoolant temperature
gaugeIVisualGauge less than 3/4 when
drivingÐ
ICoolant overflow to res-
ervoir tankIVisualNo overflow during driving
and idlingSee LC section, ªChanging
Engine Coolantº.
OFF*
410ICoolant return from res-
ervoir tank to radiatorIVisualShould be initial level in
reservoir tankSee LC section, ªREFILL-
ING ENGINE COOLANTº.
OFF11ICylinder headIStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See EM section, ªInspec-
tionº.
12ICylinder block and pis-
tonsIVisualNo scuffing on cylinder
walls or pistonSee EM section, ªInspec-
tionº.
*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 section, ªOVERHEATING CAUSE ANALYSISº.
DTC P1217 OVER HEATTD27Ti
EC-425

Component Description
NEEDLE LIFT SENSOR (NLS)
The needle lift sensor is built into the No. 1 nozzle. Its inductive
pickup element senses fuel injection timing. It is sent as a pulse
signal to the ECM for feed-back the actual fuel injection timing and
calculating the secondary engine speed.
On Board Diagnosis Logic
DTC Malfunction is detected when ....Check Items
(Possible Cause)
P1240
0304IAn incorrect signal from the sensor is sent to ECM.IHarness or connectors
(The sensor circuit is open or short-circuited.)
INeedle lift sensor
P1242
0906
DTC Confirmation Procedure
NOTE:
Before DTC confirmation, be sure to check battery voltage is
above 9V.
WITH CONSULT-II
1) Turn ignition switch to ªONº position and select ªDATA MONI-
TORº mode with CONSULT-II.
2) Start engine.
3) Run it for 2 seconds at above 1,200 rpm.
WITHOUT CONSULT-II
1) Start engine.
2) Run it for 2 seconds at above 1,200 rpm.
3) Turn ignition switch to ªLOCKº position, wait at least 5 seconds
and then turn to ªONº position.
4) Perform ªDiagnostic Test Mode IIº (Self-diagnostic results).
NEF689
DTC P1240 NEEDLE LIFT SEN, DTC P1242 NEEDLE LIFT SE
(RPM)TD27Ti
EC-427

Diagnostic Procedure
INSPECTION START
CHECK FOR AIR IN FUEL FILTER.
1. Move priming pump up and down to
purge air from fuel filter.
2. Perform ªDIAGNOSTIC TROUBLE
CODE CONFIRMATION PROCE-
DUREº.
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch to ªLOCKº position.
2. Disconnect ECM harness connector
and needle lift sensor harness connec-
tor.
3. Check harness continuity between
needle lift sensor connector terminalq
1and ECM connector terminal345.
Refer to wiring diagram.
Continuity should exist.
If OK, check harness for short-circuit.
OK
ENG
Check the following:
IHarness for open circuit
between needle lift sen-
sor and ECM
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT-I.
Check harness continuity between needle
lift sensor connector terminalsq
2and ECM
connector terminals333. Refer to wiring
diagram.
Continuity should exist.
If OK, check harness for short-circuit.
OK
ENG
Check the following:
IHarness for open or
short-circuit between
ECM and needle lift sen-
sor.
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT-II.
Check resistance between ECM connector
terminal
346and engine ground. Refer to
wiring diagram.
Continuity should exist.
If OK, check harness for short-circuit.
OK
ENG
Check the following:
IHarness for open-circuit
between ECM and
engine ground
If NG, repair harness or
connectors.
CHECK NO. 1 INJECTION NOZZLE FOR
CLOGGING.
Refer to spray pattern test of ªINJECTION
NOZZLEº.
If NG, replace No. 1 injection nozzle.
qA
NEF591
NEF690
NEF463
H
H
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H
H
H
DTC P1240 NEEDLE LIFT SEN, DTC P1242 NEEDLE LIFT SE
(RPM)TD27Ti
EC-429

Diagnostic Procedure
EGR CONTROL
INSPECTION START
CHECK OVERALL FUNCTION.
1. Start engine and warm it up sufficiently.
2. Perform diagnostic test mode II (Self-
diagnostic results).
Make sure that diagnostic trouble code
P0000 (0505) is displayed.
3. Make sure that EGR valve spring
moves up and down (Use your finger)
under the following conditions.
At idle:
Spring does not move.
Racing engine from idle to 3,000
rpm:
Spring moves up and down.
4. Make sure that throttle control valve rod
moves up and down under the following
conditions.
At idle:
Rod does not move.
Racing engine from idle to 3,000
rpm:
Rod moves up and down.
NG
EOK
INSPECTION END
CHECK VACUUM SOURCES TO EGR
VALVE AND THROTTLE CONTROL
VA LV E .
1. Disconnect vacuum hoses to EGR
valve and throttle control valve.
2. Make sure that vacuum exists under
the following conditions.
At idle:
Vacuum should exist.
Racing engine from idle to 3,000
rpm:
Vacuum should not exist.
NG
EOK
CHECK COMPONENTS
(EGR valve and throttle
control valve).
(See page EC-439.)
NG
Replace malfunctioning
component(s).
qA
YEC243A
NEF509
YEC244A
NEF511
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DTC P1404 EGR SOL/V A, DTC P1405 EGR SOL/V B/P1407
THROTTLE SOLENOID VALVETD27Ti
EC-436