
On Board Diagnosis LogicNCEC0202When a misfire occurs, the engine speed will fluctuate. If the engine speed fluctuates enough to cause the
CKP sensor signal to vary, The ECM can determine that a misfire is occurring.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to
overheating, the MI will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MI will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MI will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MI will remain on.
If another misfire condition occurs that can damage the TWC, the MI will begin to blink again.
(After the first trip detection, the MI will light up from engine starting. If a misfire is detected that will cause
three way catalyst damage, the MI will start blinking.)
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect emissions), the MI will only light when
the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sensor signal
every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0300
0300IMultiple cylinders misfire.IImproper spark plug
IInsufficient compression
IIncorrect fuel pressure
IEGR volume control valve (If so equipped)
IThe injector circuit is open or shorted
IInjectors
IIntake air leak
IInsufficient ignition spark
ILack of fuel
IHeated oxygen sensor 1 (front) P0301
0301INo. 1 cylinder misfires.
P0302
0302INo. 2 cylinder misfires.
P0303
0303INo. 3 cylinder misfires.
P0304
0304INo. 4 cylinder misfires.
DTC Confirmation ProcedureNCEC0203CAUTION:
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, and select ªDATA MONITORº mode
with CONSULT-II.
NEF068A
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIREQG16I18DE
On Board Diagnosis Logic
EC-222

System DescriptionNCEC0433COOLING FAN CONTROLNCEC0433S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor or ABS actuator and
electric unit (control unit)Vehicle speed
Cooling fan
controlCooling fan relay(s) Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch Air conditioner ªONº signal
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refriger-
ant pressure, and air conditioner ON signal. The control system has ON-OFF control.
The refrigerant pressure sensor uses an electrostatic volume pressure transducer to convert refrigerant pres-
sure to voltage. The transducer is installed in the liquid tank of the air conditioner system.
OPERATIONNCEC0433S02Engine coolant temperatures at which the cooling fan turns ªONº are indicated in the Table below.
Vehicle speed km/h (MPH)
Air conditioner switchHigh pressure of
refrigerant
kPa (bar, kg/cm
2, psi)Less than 20 (12) 20 - 80 (12 - 50) More than 80 (50)
ONMore than 1,760
(17.6, 17.95, 255)Always Always More than 95ÉC (203ÉF)
Less than 1,760
(17.6, 17.95, 255)Always More than 95ÉC (203ÉF) More than 95ÉC (203ÉF)
OFFMore than 100ÉC
(212ÉF)More than 95ÉC (203ÉF) More than 95ÉC (203ÉF)
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0486Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIGIEngine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates)ON
COOLING FANIAfter warming up engine, idle
the engine.
IAir conditioner switch: OFFEngine coolant temperature is less
than 99ÉC (210ÉF)OFF
Engine coolant temperature is
100ÉC (212ÉF) or moreON
SEF099X
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
System Description
EC-289

ECM Terminals and Reference Value=NCEC0487Specification 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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
13 LG/R Cooling fan relay[Engine is running]
ICooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
ICooling fan is operatingApproximately 0V
23 L/W Air conditioner switch[Engine is running]
IBoth air conditioner switch and blower switch are
ªONº (Compressor operates)Approximately 0V
[Engine is running]
IAir conditioner switch is ªOFFºBATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNCE0488If 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.
Diagnostic
Trouble Code
No.Malfunction is detected when ...Check Items
(Possible Cause)
P1217
1217ICooling fan does not operate properly (Overheat).
ICooling fan system does not operate properly (Overheat).
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
For more information, refer to ªMAIN 12 CAUSES
OF OVERHEATINGº, EC-QG-298.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the MA
section (ªChanging Engine Coolantº, ªENGINE MAINTENANCEº). 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 (ªAnti-freeze Coolant Mixture Ratioº, ªRECOM-
MENDED FLUIDS AND LUBRICANTSº).
2) After refilling coolant, run engine to ensure that no water-flow noise is emitted.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
ECM Terminals and Reference Value
EC-290

Overall Function CheckNCEC0489Use 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 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-QG-294.
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-QG-294.
3) Turn ignition switch ªONº.
4) Perform ªCOOLING FANº in ªACTIVE TESTº mode with CON-
SULT-II.
5) If the results are NG, go to ªDiagnostic Procedureº, EC-QG-
294.
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-QG-294.
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-QG-294.
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 fan operates.
If NG, go to ªDiagnostic Procedureº, EC-QG-294.
SEF621WA
SEF111X
SEC163BA
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
Overall Function Check
EC-291

Diagnostic ProcedureNCEC0491
1 CHECK COOLING FAN OPERATION
1. Start engine and let it idle.
2. Set temperature lever at full cold position.
3. Turn air conditioner switch ªONº.
4. Turn blower fan switch ªONº.
5. Make sure that cooling fans-1 and -2 operate.
SEC163BA
OK or NG
OK©GO TO 11.
NG©GO TO 2.
2 CHECK AIR CONDITIONER OPERATION
Is air conditioner operating?
(Check operation of compressor and blower motor.)
OK or NG
OK©GO TO 3.
NG©Check for failure of air conditioner to operate. Refer to HA section.
3 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan relay.
3. Turn ignition switch ªONº.
4. Check voltage between terminals 2, 3 and ground with CONSULT-II or tester.
SEF112XVoltage: Battery voltage
OK or NG
OK©GO TO 5.
NG©GO TO 4.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
Diagnostic Procedure
EC-294

12 CHECK RADIATOR CAP
Apply pressure to cap with a tester.
SLC755ARadiator 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.
SLC343Valve opening temperature:
76.5ÉC (170ÉF) [standard]
Valve lift:
More than 8 mm/90ÉC (0.31 in/194ÉF)
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-QG-124.
OK or NG
OK©GO TO 15.
NG©Replace engine coolant temperature sensor.
15 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-QG-298.
©INSPECTION END
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
Diagnostic Procedure (Cont'd)
EC-297

Main 12 Causes of OverheatingNCEC0492
Engine Step Inspection item Equipment Standard Reference page
OFF 1IBlocked radiator
IBlocked condenser
IBlocked radiator grille
IBlocked bumperIVisual No blocking Ð
2ICoolant mixtureICoolant tester 50 - 50% coolant mixture See ªRECOMMENDED
FLUIDS AND LUBRI-
CANTSº in MA section.
3ICoolant levelIVisual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee ªChanging Engine
Coolantº, ªENGINE
MAINTENANCEº in MA
section.
4IRadiator capIPressure tester 59 - 98 kPa
(0.59 - 0.98 bar, 0.6 - 1.0
kg/cm
2,9-14psi) (Limit)See ªSystem Checkº,
ªENGINE COOLING
SYSTEMº in LC section.
ON*
25ICoolant leaksIVisual No leaks See ªSystem Checkº,
ªENGINE COOLING
SYSTEMº in LC section.
ON*
26IThermostatITouch the upper and
lower radiator hosesBoth hoses should be hot See ªThermostatº and
ªRadiatorº, ªENGINE
COOLING SYSTEMº in
LC section.
ON*
17ICooling fanICONSULT-II Operating See ªTROUBLE DIAG-
NOSIS FOR OVER-
HEATº (EC-QG-289).
OFF 8ICombustion gas leakIColor checker chemical
tester 4 Gas analyzerNegative Ð
ON*
39ICoolant temperature
gaugeIVisual Gauge less than 3/4
when drivingÐ
ICoolant overflow to
reservoir tankIVisual No overflow during driv-
ing and idlingSee ªChanging Engine
Coolantº, ªENGINE
MAINTENANCEº in MA
section.
OFF*
410ICoolant return from
reservoir tank to radia-
torIVisual Should be initial level in
reservoir tankSee ªENGINE MAINTE-
NANCEº in MA section.
OFF 11ICylinder headIStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See ªInspectionº, ªCYLIN-
DER HEADº in EM sec-
tion.
12ICylinder block and pis-
tonsIVisual No scuffing on cylinder
walls or pistonSee ªInspectionº, ªCYLIN-
DER BLOCKº in EM sec-
tion.
*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 ªOVERHEATING CAUSE ANALYSISº in LC section.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
Main 12 Causes of Overheating
EC-298

Component InspectionNCEC0493COOLING FAN RELAYSNCEC0493S01Check continuity between terminals 3 and 5.
Conditions Continuity
12V direct current supply between terminals 1 and
2Ye s
No current supply No
If NG, replace relay.
COOLING FAN MOTORS-1 AND -2NCEC0493S021. Disconnect cooling fan motor harness connectors.
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Terminals
(+) (þ)
Cooling fan motor 1 2
Cooling fan motor should operate.
If NG, replace cooling fan motor.
REFRIGERANT PRESSURE SENSORNCEC0493S03With the refrigerant pressure sensor installed on the vehicle, start
the engine and while idling, read the voltage at refrigerant pressure
sensor terminals 1 and 2. (Refer to wiring diagram.)
Air conditioner condition Voltage V
OFF More than approx. 0.3V
ON More than approx. 1.5V
ON to OFF Decreasing gradually
If results are NG, check for 5V between refrigerant sensor termi-
nal 3 and ground. If there is 5V, replace sensor.
SEF511P
SEF721Q
DTC P1217 OVERHEAT (COOLING SYSTEM)QG16I18DE
Component Inspection
EC-299