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DTC P0301, P0302, P0303, P0304, P0305, P0306 [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))

BME010200100W09

DTC P0301 DTC P0302 DTC P0303 DTC P0304 DTC P0305

DTC P0306

Cylinder No.1 misfire detection

Cylinder No.2 misfire detection

Cylinder No.3 misfire detection

Cylinder No.4 misfire detection

Cylinder No.5 misfire detection

Cylinder No.6 misfire detection
DETECTION CONDITION | • PCM monitors crankshaft position sensor input signal interval time. PCM calculates the change of the interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, PCM detects a misfire in the corresponding cylinder. While the engine is running, PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, PCM determines that a misfire, which can damage the catalytic converter or affect emission performance, has occurred. Diagnostic support note
• This is a continuous monitor (MISFIRE).
• The MIL illuminates if the PCM detects the misfire which affects emission performance in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• The MIL flashes if the PCM detects misfire which can damage the catalytic converter during first drive cycle.
• PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
• FREEZE FRAME DATA is available.
• DTC is stored in the PCM memory.
POSSIBLE CAUSE | • Spark plug malfunction • Ignition system malfunction • Fuel injector malfunction • Air suction in intake air system (between dynamic chamber and cylinder head) • Inadequate engine compression due to engine internal malfunction
• Related connector or terminal malfunction
• Related wiring harness malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (Misfire related) been recorded? | Yes | Go to the next step.
No | Record FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on repair order, then go to the next step.
2 | VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Check for related Service Information availability. • Is any related Service Information available? | Yes | Perform repair or diagnosis according to available Service Information. • If vehicle is not repaired, go to next step.
No | Go to next step.
3 | VERIFY RELATED PENDING CODE OR STORED DTCS • Turn the ignition switch off then ON (Engine OFF). • Verify related pending code or stored DTCs. • Is other DTCs present? | Yes | Go to appropriate DTC troubleshooting. (See DTC TABLE [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed)).)
No | Go to next step.
4 | VERIFY CURRENT INPUT SIGNAL STATUS (IGNITION SWITCH TO ON /IDLE) • Access ECT, IAT, MAF, RPM, TP and VSS PIDs using WDS or equivalent. (See PCM INSPECTION [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed)).)
• Is there any signal that is far out of specification when ignition switch is ON and engine runs at idle?
Yes
Inspect suspected circuit and/or part according to inspection results. Then go to Step 12.
(See PCM INSPECTION [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed)).)
No | Go to next step.
5 | VERIFY CURRENT INPUT SIGNAL STATUS UNDER TROUBLE CONDITION • Inspect PID while simulating FREEZE FRAME DATA condition. • Is there any signal which causes drastic changes? | Yes | Inspect suspected circuit and/or part according to inspection results. Then go to Step 12. (See PCM INSPECTION [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed)).)
No | Go to next step.
6 | INSPECT SPARK PLUG CONDITION • Turn the ignition switch off. • Remove spark plug from suspected cylinder. • Check spark plug condition:

  - Cracks
  - Excess wear
  - Gap
  - Wet

• Is any problem found on spark plug?
Yes
• If spark plug is wet, fuel flooding is suspected. Go to step 8.
• If spark plug has a cracks, excess wear or improper gap, replace faulty spark plug. Then go to Step 12.
No | Go to next step.
7 | INSPECT FUEL INJECTOR HARNESS • Remove intake air system parts. • Disconnect fuel injector connector on suspected cylinder. • Connect NOID LIGHT to fuel injector connector terminals. • Check dim of light during cranking? | Yes | Go to next step.
No | Check for fuel injector harnesses. Repair or replace it if necessary, then go to Step 12.
8 | INSPECT FUEL INJECTOR OPERATION • Remove fuel injector from suspected cylinder. • Swap injector with injector on other cylinder. • Start engine and run it at idle. • Is misfire DTC for cylinder which has a suspected fuel injector? | Yes | Replace injector, then go to step 12.
No | Go to next step.
9 | INSPECT FOR AIR SUCTION AT INTAKE AIR SYSTEM • Inspect for air leakage at following:

  - Around connection of dynamic chamber and intake manifold
  - Around connection of intake manifold and cylinder head

• Is air leakage found?
Yes
Repair or replace suspected part, then go to Step 12.
No | Go to next step.
10 | INSPECT SEALING OF ENGINE COOLANT PASSAGE

  Warning

  • Removing radiator cap when radiator is hot is dangerous, Scalding coolant and steam may shoot out and cause serious injury.
  • When removing radiator cap, wrap thick cloth around and turn it slowly.

• Remove radiator cap.
• Implement procedure to bleed air from engine coolant, then run engine at idle.
• Is there any small bubble which makes engine coolant white at filling opening?

  Note

  • Large bubbles are normal since they are remaining air coming out from engine coolant passage.

Yes
Air gets in from poor sealing on head gasket or other areas between combustion chamber and engine coolant passage. Repair or replace faulty parts, then go to Step 12.
No | Go to next step.
11 | INSPECT ENGINE COMPRESSION • Inspect engine compression. • Is engine compression normal? | Yes | Go to next step.
No | Overhaul the engine, then go to next step.
12 | VERIFY TROUBLESHOOTING OF MISFIRE DTC COMPLETED • Make sure to reconnect all disconnected connectors. • Start engine. • Clear DTC from PCM memory using WDS or equivalent. • Run PCM adaptive memory procedure drive mode.
(See OBD DRIVE MODE [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed)).)
• Is same PENDING CODE or stored code of same DTC present?
Yes
Replace PCM, then go to next step.
No | Go to next step.
13 | VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [AJ].) • Is there any DTC present? | Yes | Go to applicable DTC inspection. (See DTC TABLE [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed)).)
No | Troubleshooting completed.