
Description
SYSTEM DESCRIPTION
SensorInput signal to ECM ECM functionActuator
Engine coolant temperature
sensor Engine 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
0208 I
Cooling fan does not operate properly (Overheat).
I Cooling fan system does not operate properly (Over-
heat).
I Engine coolant was not added to the system using
the proper filling method. I
Harness or connectors
(The cooling fan circuit is open or shorted.)
I Cooling fan
I Radiator hose
I Radiator
I Radiator cap
I Water pump
I Thermostat
I Engine coolant temperature sensor
For more information, refer to ªMAIN 12 CAUSES OF
OVERHEATINGº, EC-448.
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-441
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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-444.
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-444.
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-444.
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-444.
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-444.
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 150W resistor 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-444.
AEC640
SEF111X
SEC163BA
MEC475B
DTC P1217 OVER HEATTD27Ti
EC-442
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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 (1.57 bar, 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
I Radiator
I Water pump
Refer to LC section (ªWater
Pumpº).
CHECK RADIATOR CAP.
Apply pressure to cap with a tester.
Radiator cap relief pressure: 78 - 98 kPa (0.78 - 0.98 bar, 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-449.
OK
ENGReplace engine coolant
temperature sensor.
If the cause can not be isolated, go to
ªMAIN 12 CAUSES OF OVERHEATINGº
on EC-448.
INSPECTION END
SLC754A
SLC755A
SLC343
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DTC P1217 OVER HEATTD27Ti
Diagnostic Procedure (Cont'd)
EC-447
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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
DTCMalfunction is detected when .... Check Items
(Possible Cause)
P1240
0304 I
An incorrect signal from the sensor is sent to ECM. IHarness or connectors
(The sensor circuit is open or short-circuited.)
I Needle 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-450
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Diagnostic Procedure
INSPECTION START
CHECK FOR AIR IN FUEL FILTER.
1. Move priming pump up and down topurge 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 terminal q
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 terminals q
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
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DTC P1240 NEEDLE LIFT SEN, DTC P1242 NEEDLE LIFT SE (RPM)TD27Ti
EC-452
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qA
CHECK COMPONENT.
(Needle lift sensor)
Refer to ªCOMPONENT INSPECTIONº on
EC-453.ENGReplace needle lift sensor.
Disconnect and reconnect harness con-
nectors in the circuit. Then retest.
Trouble is not fixed.
Check ECM pin terminals for damage and
check the connection of ECM harness
connector. Reconnect ECM harness con-
nector and retest.
INSPECTION END
Component Inspection
NEEDLE LIFT SENSOR
1. Disconnect needle lift sensor harness connector.
2. Check continuity between needle lift sensor terminals q
1and
q
2.
Resistance: Approximately 105W [at 25ÉC (77ÉF)]
If NG, replace needle lift sensor with injection nozzle holder.
MEC962D
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DTC P1240 NEEDLE LIFT SEN, DTC P1242 NEEDLE LIFT SE (RPM)TD27Ti
Diagnostic Procedure (Cont'd)
EC-453
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System Description
EGR CONTROL
Camshaft position sensor (TDC)EEngine speedECMEEGRC-solenoid valve A
Mass air flow sensorEMass air flowEEGRC-solenoid valve B
Engine coolant temperature sensorEEngine coolant temperatureEThrottle control solenoid valve
Ignition switchEStart signal
Atmospheric pressure sensor
EAtmospheric pressure
Air conditioner switch
EAir conditioner ªONº signal
The ECM receives signals sent from the engine coolant tempera-
ture sensor, crankshaft position sensor (TDC), ignition switch etc.
to determine engine speed and operating conditions. Based on
these signals, the ECM controls EGRC-solenoid valve (A and B)
operation and throttle solenoid valve operation.
The EGR control stops when engine coolant temperature is below
45ÉC (113ÉF), at idling, at starting and when the system compo-
nents and engine speed signals are disordered.
Engine coolant temperature ÉC (ÉF) Load
EGRC-solenoid valve
Throttle control
solenoid valve EGR valveThrottle control
valve Amount of EGR
gas
AB
Below 45 (113) Any OFF
(Closed) OFF
(Closed) OFF
(Closed) Fully closed Fully open Ð
Above 45 (113) Low load
ON
(Open) ON
(Open) ON
(Open) Fully open Closed Large
Medium load-1 ON
(Open) ON
(Open) OFF
(Closed) Fully open Fully open Medium
Medium load-2 ON
(Open) OFF
(Closed) OFF
(Closed) Half open Fully open Small
High load OFF
(Closed) OFF
(Closed) OFF
(Closed) Fully closed Fully open Ð
Component Description
The EGRC-solenoid valves A and B, control vacuum pressure act-
ing on the EGR valve. The EGR control valve will be fully opened,
half-opened or fully closed, as required.
The throttle control solenoid valve controls vacuum pressure acting
on the throttle control valve. Thus, intake air passages are opened
or closed in relation to exhaust gas and intake air. Utilizing the
relationship between exhaust gas pressure and intake air pressure
control, the amount of EGR (exhaust gas recirculated) is regulated
in three approximate measures Ð large, medium, small.
NEF513
DTC P1404 EGR SOL/V A, DTC P1405 EGR SOL/V B/P1407
THROTTLE SOLENOID VALVETD27Ti
EC-454
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Component Description
AIR CONDITIONER CUT CONTROL
Air conditioner is cut under the following conditions:
IStarting engine
I Quick acceleration from low speed
I Undershooting of idle speed
I High engine coolant temperature [above 107ÉC (225ÉF)]
I Malfunctioning of engine speed sensor, accelerator position sen-
sor or vehicle speed sensor when engine speed is below 2,100
rpm.
On Board Diagnosis Logic
DTC Malfunction is detected when .... Check Items
(Possible cause)
P1530
0805 I
Air conditioner relay signal circuit is shorted. IHarness or connectors
(The air conditioner relay signal circuit is shorted.)
I Air conditioner relay
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch and air conditioner switch to ªONº position.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 2 seconds.
WITHOUT CONSULT-II
1) Turn ignition switch and air conditioner switch to ªONº position.
Wait at least 2 seconds.
2) Turn ignition switch to ªLOCKº position, wait at least 5 seconds and then turn to ªONº position.
3) Perform ªDiagnostic Test Mode IIº (Self-diagnostic results).
DTC P1530 AIR CONDITIONER RLYTD27Ti
EC-463
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