Page 665 of 2267

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-
QG-223.
With GST
Follow the procedure ªWith CONSULT-IIº above.
Diagnostic ProcedureNCEC0204
1 CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
OK or NG
OK©GO TO 2.
NG©Discover air leak location and repair.
2 CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG
OK©GO TO 3.
NG©Repair or replace it.
3 CHECK EGR FUNCTION (If so equipped)
Perform DTC Confirmation Procedure for DTC P1402 EGR FUNCTION (OPEN).
Refer to EC-QG-305.
OK or NG
OK©GO TO 4.
NG©Repair EGR system.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIREQG16I18DE
DTC Confirmation Procedure (Cont'd)
EC-223
Page 666 of 2267
4 PERFORM POWER BALANCE TEST
With CONSULT-II
1. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode.
NEF105A
2. Is there any cylinder which does not produce a momentary engine speed drop?
Without CONSULT-II
When disconnecting each injector harness connector one at a time, is there any cylinder which does not produce a
momentary engine speed drop?
SEF055X
YesorNo
Ye s©GO TO 5.
No©GO TO 7.
5 CHECK INJECTOR
Does each injector make an operating sound at idle?
MEC703B
YesorNo
Ye s©GO TO 6.
No©Check injector(s) and circuit(s). Refer to EC-QG-319.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIREQG16I18DE
Diagnostic Procedure (Cont'd)
EC-224
Page 667 of 2267

6 CHECK IGNITION SPARK
1. Turn Ignition switch ªOFFº.
2. Disconnect ignition coil assembly from rocker cover.
3. Connect a known good spark plug to the ignition coil assembly.
4. Place end of spark plug against a suitable ground and crank engine.
5. Check for spark.
SEF575Q
OK or NG
OK©GO TO 7.
NG©Check ignition coil, power transistor and their circuits. Refer to EC-QG-323.
7 CHECK SPARK PLUGS
Remove the spark plugs and check for fouling, etc.
SEF156I
OK or NG
OK©GO TO 8.
NG©Repair or replace spark plug(s) with standard type one(s). For spark plug type, refer to
ªENGINE MAINTENANCEº in MA section.
8 CHECK COMPRESSION PRESSURE
Refer to EM section.
ICheck compression pressure.
Standard:
1,324 kPa (13.24 bar, 13.5 kg/cm
2, 192 psi)/350 rpm
Minimum:
1,128 kPa (11.28 bar, 11.5 kg/cm
2, 164 psi)/350 rpm
Difference between each cylinder:
98 kPa (0.98 bar, 1.0 kg/cm
2, 14 psi)/350 rpm
OK or NG
OK©GO TO 9.
NG©Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIREQG16I18DE
Diagnostic Procedure (Cont'd)
EC-225
Page 668 of 2267

9 CHECK FUEL PRESSURE
1. Install any parts removed.
2. Release fuel pressure to zero. Refer to EC-QG-29.
3. Install fuel pressure gauge and check fuel pressure.
SEF925W
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.
IFuel pump and circuit Refer to EC-QG-336.
IFuel pressure regulator Refer to EC-QG-30.
IFuel lines Refer to ªENGINE MAINTENANCEº in MA section.
IFuel filter for clogging
©Repair or replace.
11 CHECK IGNITION TIMING
Perform ªBasic Inspectionº.
Refer to EC-QG-72.
OK or NG
OK©GO TO 12.
NG©1. Perform ªIdle Air Volume Learningº. Refer to EC-QG-33.
2. Check camshaft position sensor (PHASE) (EC-QG-238) and crankshaft position sen-
sor (POS) (EC-QG-232).
12 CHECK HEATED OXYGEN SENSOR 1 (FRONT)
Refer to ªComponent Inspectionº, EC-QG-231.
OK or NG
OK©GO TO 13.
NG©Replace Heated oxygen sensor 1 (front).
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIREQG16I18DE
Diagnostic Procedure (Cont'd)
EC-226
Page 669 of 2267

13 CHECK MASS AIR FLOW SENSOR
With CONSULT-II
Check ªMASS AIR FLOWº in ªDATA MONITORº mode with CONSULT-II.
at idling: 1.0 - 4.0 g×m/sec
at 2,500 rpm: 5.0 - 10.0 g×m/sec
With GST
Check mass air flow sensor signal in MODE 1 with GST.
at idling: 1.0 - 4.0 g×m/sec
at 2,500 rpm: 5.0 - 10.0 g×m/sec
OK or NG
OK©GO TO 15.
NG©GO TO 14.
14 CHECK CONNECTORS
Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or engine grounds.
Refer to EC-QG-110.
OK or NG
NG©Repair or replace it.
15 CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in ªSymptom Matrix Chartº, EC-QG-82.
OK or NG
OK©GO TO 16.
NG©Repair or replace.
16 ERASE THE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.
Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to EC-QG-44.
©GO TO 17.
17 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-QG-102.
©INSPECTION END
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE,
MULTIPLE CYLINDER MISFIREQG16I18DE
Diagnostic Procedure (Cont'd)
EC-227
Page 670 of 2267

Component DescriptionNCEC0206The knock sensor is attached to the cylinder block. It senses
engine knocking using a piezoelectric element. A knocking vibration
from the cylinder block is sensed as vibrational pressure. This
pressure is converted into a voltage signal and sent to the ECM.
Freeze frame data will not be stored in the ECM for the knock
sensor. The MI will not light for knock sensor malfunction. The
knock sensor has one trip detection logic.
ECM Terminals and Reference ValueNCEC0207Specification 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)
81 W Knock sensor[Engine is running]
IIdle speed1.0 - 4.0V
On Board Diagnosis LogicNCEC0208
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0325
0325IAn excessively low or high voltage from the knock sen-
sor is sent to ECM.IHarness or connectors
(The knock sensor circuit is open or shorted.)
IKnock sensor
DTC Confirmation ProcedureNCEC0209NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 10V at idle.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and run it for at least 5 seconds at idle speed.
3) If DTC is detected, go to ªDiagnostic Procedureº, EC-QG-230.
With GST
Follow the procedure ªWith CONSULT-IIº above.
SEF598K
NEF068A
DTC P0325 KNOCK SENSOR (KS)QG16I18DE
Component Description
EC-228
Page 671 of 2267
Wiring DiagramNCEC0210
YEC269
Detectable line for DTC
Non-detectable line for DTC ECM
KNOCK
SENSOR
DTC P0325 KNOCK SENSOR (KS)QG16I18DE
Wiring Diagram
EC-229
Page 672 of 2267
Diagnostic ProcedureNCEC0211
1 RETIGHTEN GROUND SCREWS
Loosen and retighten engine ground screws.
SEF994W
©GO TO 2.
2 CHECK INPUT SIGNAL CIRCUIT-1
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector and knock sensor harness connector.
SEF056X3. Check harness continuity between knock sensor signal terminal 2 and ECM terminal 81.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the harness for open or short between knock sensor and ECM.
©Repair open circuit or short to ground or short to power in harness or connectors.
4 CHECK KNOCK SENSOR
Knock sensor
Refer to ªComponent Inspectionº, EC-QG-231.
OK or NG
OK©GO TO 5.
NG©Replace knock sensor.
View from the underside of the vehicle
Knock sensor
harness
connector
Oil filter
DTC P0325 KNOCK SENSOR (KS)QG16I18DE
Diagnostic Procedure
EC-230