EC
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DTC P0300 - P0304 MULTIPLE CYLINDER
MISFIRE, NO. 1 - 4 CYLINDER
MISFIRE
On Board Diagnosis Logic INFOID:0000000004537254
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary , ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage) On the 1st trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor (POS) signal every 200 engine revo-
lutions for a change.
When the misfire condition decreases to a level t hat will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level t hat will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration) For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
light when the misfire is detected on a second trip. Du ring this condition, the ECM monitors the CKP sen-
sor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC Confirmation Procedure INFOID:0000000004537255
CAUTION:
Always drive vehicle in safe manner according to traf fic conditions and obey all traffic laws when driv-
ing.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Restart engine and let it idle for about 15 minutes.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-766, " Diagnosis Procedure " .
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditi ons to (1st trip) Freeze Frame Data for a certain
time. Refer to table below. Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300 Multiple cylinder misfire
detected Multiple cylinder misfire.
• Improper spark plug
• Insufficient compression
• Incorrect fuel pressure
• Fuel injector circuit is open or shorted
• Fuel injector
• Intake air leak
• The ignition signal circuit is open or shorted
• Lack of fuel
• Drive plate or flywheel
• Air fuel ratio (A/F) sensor 1
• Incorrect PCV hose connection
P0301
0301 No.1 cylinder misfire de-
tected No. 1 cylinder misfires.
P0302
0302 No. 2 cylinder misfire
detected No. 2 cylinder misfires.
P0303
0303 No. 3 cylinder misfire
detected No. 3 cylinder misfires.
P0304
0304 No. 4 cylinder misfire
detected No. 4 cylinder misfires.
DTC P0300 - P0304 MULTIPLE CYLINDER
MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
EC-767
< SERVICE INFOMATION >
[MR TYPE 1] C
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No >> GO TO 9. 4.
CHECK FUEL INJECTOR
Does each fuel injector make an operating sound at idle?
Yes or No Yes >> GO TO 5.
No >> Check fuel injector(s) and circuit(s). Refer to EC-986 .
5.
CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pres-
sure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
- : Vehicle front
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri- cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spar k plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the el ectrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG OK >> GO TO 9.
NG >> GO TO 6. 6.
CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion. PBIB3332E
Spark should be generated. PBIB2958E
PBIB2325E
EC-768< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0300 - P0304 MULTIPLE CYLINDER
MISFIRE, NO. 1 - 4 CYLINDER MIS-
FIRE
OK or NG OK >> GO TO 7.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-996 .
7.
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG OK >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to EM-227, " Standard and Limit " .
NG >> 1. Repair or clean spark plug.
2. GO TO 8. 8.
CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug
and the grounded portion.
OK or NG OK >>
INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-227, " Standard
and Limit " .
9.
CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-185, " On-Vehicle Service " .
OK or NG OK >> GO TO 10.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets. 10.
CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-574, " Fuel Pressure Check " .
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-574, " Fuel Pressure Check " .
OK or NG OK >> GO TO 12.
NG >> GO TO 11. 11.
DETECT MALFUNCTIONING PART
Check the following.
• Fuel pump and circuit (Refer to EC-991 .)
• Fuel pressure regulator (Refer to EC-574, " Fuel Pressure Check " .)
• Fuel lines (Refer to EM-156 .)
• Fuel filter for clogging
>> Repair or replace. 12.
CHECK IGNITION TIMING
Check the following items. Refer to EC-566, " Basic Inspection " .
Spark should be generated.
SEF156I
Spark should be generated.
At idling: Approximately 350 kPa (3.57 kg/cm 2
, 51 psi)
DTC P0420 THREE WAY CATALYST FUNCTION
EC-787
< SERVICE INFOMATION >
[MR TYPE 1] C
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DTC P0420 THREE WAY CATALYST FUNCTION
On Board Diagnosis Logic INFOID:0000000004537280
The ECM monitors the switching frequency ratio of air fuel ratio (A/F)
sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decr eases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation Procedure INFOID:0000000004537281
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches to 70°C (158 °F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecutive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.
10. Wait 5 seconds at idle.
11. Rev engine up to 2,000 to 3,000 rpm and maintain it unt il “INCMP” of “CATALYST” changes to “CMPLT” (It
will take approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70 °C (158 °F) and then retest from step 1.
12. Check 1st trip DTC. If 1st trip DTC is detected, go to EC-788, " Diagnosis Procedure " .
Overall Function Check INFOID:0000000004537282
Use this procedure to check the overall function of the th ree way catalyst (manifold). During this check, a 1st
trip DTC might not be confirmed. SEF484YB
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420 Catalyst system efficiency
below threshold • Three way catalyst (manifold) does not operate
properly.
• Three way catalyst (manifold) does not have enough oxygen storage capacity. • Three way catalyst (manifold)
• Exhaust tube
• Intake air leaks
• Fuel injector
• Fuel injector leaks
• Spark plug
• Improper ignition timing
DTC P0420 THREE WAY CATALYST FUNCTION
EC-789
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OK or NG OK >> GO TO 5.
NG >> Follow the EC-566, " Basic Inspection " .
5.
CHECK FUEL INJECTOR
1. Stop engine and turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
4. Check voltage between ECM terminals 25, 29, 30, 31 and ground with CONSULT-III or tester.
Refer to Wiring Diagram for fuel injectors, EC-987, " Wiring Diagram " .
OK or NG OK >> GO TO 6.
NG >> Perform EC-988, " Diagnosis Procedure " .
6.
CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump (1) fuse in IPDM E/R (2) to release fuel pres-
sure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
- : Vehicle front
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri- cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spar k plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the el ectrical discharge voltage
becomes 20kV or more. Items Specifications
Target idle speed A/T: 700
± 50 rpm (in P or N position)
CVT: 700 ± 50 rpm (in P or N position)
M/T: 700 ± 50 rpm (in Neutral position)
Ignition timing A/T: 13
± 5 ° BTDC (in P or N position)
CVT: 13 ± 5 ° BTDC (in P or N position)
M/T: 13 ± 5 ° BTDC (in Neutral position) Voltage: Battery voltage
Spark should be generated. PBIB2958E
PBIB2325E
EC-790< SERVICE INFOMATION >
[MR TYPE 1]
DTC P0420 THREE WAY CATALYST FUNCTION
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG OK >> GO TO 10.
NG >> GO TO 7. 7.
CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.
OK or NG OK >> GO TO 8.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-996 .
8.
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG OK >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to EM-227, " Standard and Limit " .
NG >> 1. Repair or clean spark plug. 2. GO TO 9. 9.
CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded portion.
OK or NG OK >>
INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-227, " Standard
and Limit " .
10.
CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly. Refer to EM-156 .
Keep fuel hose and all fuel injectors connected to fuel tube.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON.
Make sure fuel does not drip from fuel injector.
OK or NG OK (Does not drip.)>>GO TO 11.
NG (Drips.)>>Replace the fuel injector(s) from which fuel is dripping. 11.
CHECK INTERMITTENT INCIDENT
Refer to EC-626 .
Spark should be generated.
SEF156I
Spark should be generated.
EC-1004< SERVICE INFOMATION >
[MR TYPE 1]
IGNITION SIGNAL
7. Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pres- sure.
NOTE:
Do not use CONSULT-III to releas e fuel pressure, or fuel pres-
sure applies again during the following procedure.
- : Vehicle front
8. Start engine.
9. After engine stalls, crank it two or three times to release all fuel
pressure.
10. Turn ignition switch OFF.
11. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
12. Remove ignition coil and spark plug of the cylinder to be checked.
13. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
14. Connect spark plug and harness connector to ignition coil.
15. Fix ignition coil using a rope etc. with gap of 13 - 17 mm between the edge of the spark plug and grounded metal portion
as shown in the figure.
16. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spar k plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the el ectrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
17. If NG, replace ignition coil with power transistor.
CONDENSER-2
1. Turn ignition switch OFF.
2. Disconnect condenser-2 harness connector.
3. Check resistance between condenser-2 terminals 1 and 2.
4. If NG, replace condenser-2.
Removal and Installation INFOID:0000000004537539
IGNITION COIL WITH POWER TRANSISTOR
Refer to EM-153 .
Spark should be generated. PBIB2958E
PBIB2325E
Resistance: Above 1 M
Ω [at 25 °C (77 °F)] PBIB0794E
BASIC SERVICE PROCEDURE
EC-1083
< SERVICE INFOMATION >
[MR TYPE 2] C
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• : Vehicle front
2. Connect No. 4 ignition coil (1) and No. 4 spark plug with suitable high-tension wire (A) as shown, and attach timing light clamp (B) to this wire.
• : Vehicle front
3. Check ignition timing. • Timing indicator (1)
Procedure After Replacing ECM INFOID:0000000004499931
When replacing ECM, the following procedure must be performed.
1. Perform initialization of NVIS (NATS) system and registration of all NVIS (NATS) ignition key IDs.
Refer to BL-249, " ECM Re-communicating Function " .
2. Perform EC-1084, " VIN Registration " .
3. Perform EC-1084, " Accelerator Pedal Released Position Learning " .
4. Perform EC-1084, " Throttle Valve Closed Position Learning " . PBIB3321E
PBIB3322E
PBIB3334E
PBIB3263E