On Board Diagnosis LogicNJEC0202If a misfire occurs, the engine speed will fluctuate. If the fluctuation is detected by the crankshaft position sen-
sor (POS), the misfire is diagnosed.
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)
When a misfire is detected which will overheat and damage the three way catalyst, the MI will start blink-
ing; even during the first trip. In this condition, ECM monitors the misfire every 200 revolutions.
If the misfire frequency decreases to a level that will not damage the three way catalyst, the MI will change
from blinking to lighting up. (After the first trip detection, the MI will light up from engine starting. If a mis-
fire is detected that will cause three way catalyst damage, the MI will start blinking.)
2. Two Trip Detection Logic (Exhaust quality deterioration)
When a misfire that will not damage the three way catalyst (but will affect exhaust emission) occurs, the
MI will light up based on two trip detection logic. In this condition, ECM monitors the misfire for every 1,000
revolutions of the engine.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0300
0300+Multiple cylinders misfire.+Improper spark plug
+Insufficient compression
+Incorrect fuel pressure
+EGR volume control valve
+The injector circuit is open or shorted
+Injectors
+Intake air leak
+Insufficient ignition spark
+Lack of fuel
+Heated oxygen sensor 1 (front) P0301
0301+No. 1 cylinder misfires.
P0302
0302+No. 2 cylinder misfires.
P0303
0303+No. 3 cylinder misfires.
P0304
0304+No. 4 cylinder misfires.
SEF058Y
DTC Confirmation ProcedureNJEC0203CAUTION:
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.
2) Start engine and warm it up to normal operating temperature.
3) Turn ignition switch ªOFFº and wait at least 9 seconds.
4) Start engine again and drive at 1,500 - 3,000 rpm for at least
3 minutes.
Hold the accelerator pedal as steady as possible.
NOTE:
Refer to the freeze frame data for the test driving conditions.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-319.
With GST
Follow the procedure ªWith CONSULT-IIº above.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
QG
On Board Diagnosis Logic
EC-318
9 CHECK FUEL PRESSURE
1. Install any parts removed.
2. Release fuel pressure to zero. Refer to EC-40.
3. Install fuel pressure gauge and check fuel pressure.
JEF087Y
At idle: Approx. 235 kPa (2.35 bar, 2.4 kg/cm2, 34 psi)OK or NG
OK ©GO TO 11.
NG ©GO TO 10.
10 DETECT MALFUNCTIONING PART
Check the following.
+Fuel pump and circuit (Refer to EC-561.)
+ Fuel pressure regulator (Refer to EC-41.)
+ Fuel lines
+ Fuel filter for clogging
©Repair or replace.
11 CHECK IGNITION TIMING
Perform ªBasic Inspectionº.
Referto EC- 100.
OK or NG
OK ©GO TO 12.
NG ©1. Perform ªIdle Air Volume Learningº. Refer to EC-57.
2. Check camshaft position sensor (PHASE) (EC-335) and crankshaft position sensor
(POS) (EC-328).
12 CHECK HEATED OXYGEN SENSOR 1 (FRONT)
Refer to ªComponent Inspectionº, EC-222.
OK or NG
OK ©GO TO 13.
NG ©Replace heated oxygen sensor 1 (front).
DTC P0300 - P0304 NO .4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
QG
Diagnostic Procedure(Cont'd)
EC-322
SEF095X
Component DescriptionNJEC0513The valve timing control system is utilized to control intake valve
opening and closing timing. Engine coolant temperature signals,
engine speed and throttle position are used to determine intake
valve timing.
The intake camshaft sprocket position is regulated by oil pressure
controlled by the intake valve timing control.
When ECM sends ON signal to intake valve timing control solenoid
valve, oil pressure is transmitted to camshaft sprocket. Then, intake
side camshaft is advanced.
OperationNJEC0514
Engine operating condition
Intake valve tim-
ing control sole-
noid valveIntake valve
opening and
closing timeValve overlap
Engine coolant
temperatureEngine speed B/FUEL SCHDL Neutral switch
20ÉC (68ÉF) -
70ÉC (158ÉF)
1,150 - 4,600
rpmAbove 3 msec
OFF ON Advance Increased
Above 70ÉC
(158ÉF)Above 7 msec
Conditions other than those above OFF Normal Normal
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0515
MONITOR ITEM CONDITION SPECIFICATION
INT/V SOL-B1+Engine: After warming up
+Lift up drive wheels and suitable
gear positionIdle OFF
Revving engine from 2,000 to
3,000 rpmON
ECM Terminals and Reference ValueNJEC0516Specification 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)
1 Y/RIntake valve timing control
solenoid valve[Engine is running]
+Idle speedBATTERY VOLTAGE
(11 - 14V)
On Board Diagnosis LogicNJEC0517
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P 1111
1111+An improper voltage signal is entered to ECM through
intake valve timing control solenoid valve.+Harness or connectors
(The intake valve timing control solenoid valve
circuit is open or shorted.)
+Intake valve timing control solenoid valve
D T C P 1111INTAKE VALVE TIMING CONTROL SOLENOID VALVEQG
Component Description
EC-393
SEF095X
Component DescriptionNJEC1769The valve timing control system is utilized to control intake valve
opening and closing timing. Engine coolant temperature signals,
engine speed and throttle position are used to determine intake
valve timing.
The intake camshaft sprocket position is regulated by oil pressure
controlled by the intake valve timing control.
When ECM sends ON signal to intake valve timing control solenoid
valve, oil pressure is transmitted to camshaft sprocket. Then, intake
side camshaft is advanced.
OperationNJEC1770
Engine operating condition
Intake valve tim-
ing control sole-
noid valveIntake valve
opening and
closing timeValve overlap
Engine coolant
temperatureEngine speed B/FUEL SCHDL Neutral switch
20ÉC (68ÉF) -
70ÉC (158ÉF)
1,150 - 4,600
rpmAbove 3 msec
OFF ON Advance Increased
Above 70ÉC
(158ÉF)Above 7 msec
Conditions other than those above OFF Normal Normal
CONSULT-II Reference Value in Data Monitor
Mode
NJEC1771
MONITOR ITEM CONDITION SPECIFICATION
INT/V SOL-B1+Engine: After warming up
+Lift up vehicle and suitable gear
positionIdle OFF
Revving engine from 2,000 to
3,000 rpmON
ECM Terminals and Reference ValueNJEC1772Specification 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)
1 Y/RIntake valve timing control
solenoid valve[Engine is running]
+Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Warm-up condition
+Lift up vehicle and suitable gear position
+Rev engine from 2,000 to 3,000 rpmApproximately 0V
INTAKE VALVE TIMING CONTROL SOLENOID VALVEQG
Component Description
EC-526
Diagnostic ProcedureNJEC0448
1 CHECK OVERALL FUNCTION
1. Turn ignition switch ªONº.
2. Pinch fuel feed hose with fingers.
JEF133Y
Fuel pressure pulsation should be felt on the fuel feed hose for 1 second after ignition switch is turned ªONº.
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect fuel pump relay.
JEF134Y
3. Turn ignition switch ªONº.
4. Check voltage between terminals 1, 5 and ground with CONSULT-II or tester.
SEF607X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
FUEL PUMPQG
Diagnostic Procedure
EC-564
Fuel Pressure RegulatorNJEC0467
Fuel pressure at idling
kPa (bar, kg/cm2, psi)Vacuum hose is connected Approximately 235 (2.35, 2.4, 34)
Vacuum hose is disconnected Approximately 294 (2.94, 3.0, 43)
Idle Speed and Ignition TimingNJEC0468
Target idle speed* rpmM/T: 700±50
A/T: 800±50
Air conditioner: ON rpm825 or more
Ignition timingM/T: 8±5É BTDC
A/T: 10±5É BTDC
Throttle position sensor idle position V 0.15 - 0.85
*: Under the following conditions:
+Air conditioner switch: OFF
+Electrical load: OFF (Lights, heater fan & rear window defogger)
+Steering wheel: Kept in straight-ahead position
Mass Air Flow SensorNJEC0470
Supply voltage (Heater) VBattery voltage (11 - 14)
Supply voltage (Sensor) VApproximately 5
Output voltage V1.0 - 1.7*
Mass air flow
(Using CONSULT-II or GST) g´m/sec1.0 - 4.0 at idle*
5.0 - 10.0 at 2,500 rpm*
*: Engine is warmed up to normal operating temperature and idling under no-load.
Intake Air Temperature SensorNJEC0480
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
80 (176) 0.27 - 0.38
Engine Coolant Temperature SensorNJEC0471
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Throttle Position SensorNJEC0477
Throttle valve conditions Voltage (V)
Completely closed0.15 - 0.85
Completely open3.5 - 4.7
Heated Oxygen Sensor 1 Heater (Front)NJEC0478
Resistance [at 25ÉC (77ÉF)]W2.3 - 4.3
Heated Oxygen Sensor 2 Heater (Rear)NJEC0483
Resistance [at 25ÉC (77ÉF)]W2.3 - 4.3
SERVICE DATA AND SPECIFICATIONS (SDS)QG
Fuel Pressure Regulator
EC-593
JEF344Y
Spill TubeNJEC0618S03RemovalNJEC0618S0301Loosen and remove the mounting bolts and flare nuts in the
reverse order of the numbers in the figure.
+When the flare nuts are loosened, hold the head of hexagonal
retaining bolts (head inside) using a wrench.
Installation
NJEC0618S03021. Tighten the flare nuts and mounting bolts in the numerical
order shown in the figure.
+When the flare nuts are tightened, hold the head of the hex-
agonal retaining bolts (head inside) using a wrench.
2. To prevent interference with the rocker cover, place the spill
gasket joint within the range shown by the arrow, then tighten
the mounting bolts. (Be especially careful about No. 2 and 4
cylinders.)
+After the spill tube is installed, check the airtightness of
the spill tube.
+After the bolts are tightened, the joint of the spill tube gasket
might be broken. However, this will not affect function.
JEF345Y
High Pressure Injection Nozzle AssemblyNJEC0618S04RemovalNJEC0618S04011. Remove the nozzle support, then pull out the high-pressure
injection nozzle assembly by turning it clockwise/
counterclockwise.
2. Using a tool such as a flat-head screwdriver, remove the cop-
per washer inside the cylinder head.
CAUTION:
Do not disassemble the high-pressure injection nozzle.
Installation
NJEC0618S04021. Insert the nozzle gasket to the cylinder head hole.
2. Attach the O-ring to the mounting groove of the nozzle side,
then insert it in the cylinder head.
TEST AND ADJUSTMENTNJEC0619WARNING:
When using nozzle tester, be careful not to allow diesel fuel
sprayed from nozzle to contact your hands or body, and make
sure your eyes are properly protected with goggles.
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont'd)
EC-616
JEF346Y
Inspection for Spill Tube AirtightnessNJEC0619S01Before the rocker cover is installed, perform the inspection as fol-
lows.
1. Connect the handy vacuum pump to the spill hose.
2. Check that the airtightness is maintained after the negative
pressure shown below is applied.
Standard:
±53.3 to ±66.7 kPa (±533 to ±667 mbar, ±400 to ±500
mmHg, ±15.75 to ±19.69 inHg)
JEF347Y
Air Bleeding of Fuel PipingNJEC0619S02After the repair, bleed air in the piping by pumping the priming
pump up and down until it becomes heavy.
JEF348Y
Injection Pressure TestNJEC0619S031. Install injection nozzle assembly to injection nozzle tester and
bleed air from flare nut.
2. Pump the tester handle slowly (one time per second) and
watch the pressure gauge.
3. Read the pressure gauge when the injection pressure just
starts dropping.
Initial injection pressure:
New
21,476 - 22,457 kPa (214.7 - 224.5 bar, 219 - 229
kg/cm
2, 3,114 - 3,256 psi)
Limit
18,275 kPa (182.7 bar, 186 kg/cm
2, 2,650 psi)
+The injection nozzle assembly has a 2-stage pressure injection
function. However, the judgement should be made at the first
stage of the valve opening pressure.
Always check initial injection pressure using a new nozzle.
BASIC SERVICE PROCEDUREYD
Injection Tube and Injection Nozzle (Cont'd)
EC-617