DTC P0300 [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)

BME010200300201

European (L.H.D.) Specs.

DTC P0300

Random misfire detection

DETECTION CONDITION

• PCM monitors CKP 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).
• MIL illuminates if PCM detects the misfire which affects emission performance in two consecutive drive cycles.
• PENDING CODE is available if PCM detects the misfire which affects emission performance during first drive cycle.
• MIL flashes if PCM detects the misfire which can damage the catalytic converter during first drive cycle. Therefore, PENDING CODE is not available while MIL flashes.
• FREEZE FRAME DATA is available.
• DTC is stored in the PCM memory.

POSSIBLE CAUSE

• CKP sensor malfunction
• CMP sensor malfunction
• Ignition coil malfunction
• Mass airflow sensor contamination
• Excess air suction in intake air system (between mass air flow sensor and dynamic chamber)
• Fuel pump malfunction
• Fuel pressure regulator malfunction
• Fuel line clogged
• Fuel filter clogged
• Fuel leakage in fuel line
• Purge control solenoid valve malfunction
• PCV valve malfunction
• EGR valve malfunction
• Vacuum hoses damages or improper connection
• Related connector and terminal malfunction
• Related wiring harness malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to the next step.
No
Record FREEZE FRAME DATA 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 the next step.
No
Go to the next step.
3
VERIFY RELATED PENDING CODE OR STORED DTCs
• Turn the ignition switch off, then to the ON position (Engine off).
• Verify related pending code or stored DTCs.
• Is other DTCs present?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS (KEY TO ON/IDLE)
• Access ECT, IAT, MAF, RPM, TP, and VSS PIDs using WDS or equivalent.
• Is there any signal that is far out of specification when the ignition switch is at the ON position and the engine runs at idle?
Yes
Inspect the circuit and/or part according to inspection results.
Then go to Step 21.
No
Go to the 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 the circuit and/or part according to inspection results.
Then go to Step 21.
No
Go to the next step.
6
INSPECT CMP SENSOR
• Inspect the CMP sensor.
• Is CMP sensor normal?
Yes
Go to the next step.
No
Inspect installation condition and damages on timing belt and gears, repair faulty parts.
• If it is normal, replace the CMP sensor.
Then go to Step 21.
7
VERIFY CKP SENSOR INSTALLATION CONDITION
• Inspect for the CKP sensor looseness.
• Is the CKP sensor loosen?
Yes
Retighten the CKP sensor, then go to Step 21.
No
Go to the next step.
8
CHECK IGNITION COIL OPERATION
• Perform spark test.
(See Spark Test.)
• Do all cylinders show blinking condition?
Yes
Go to step 11.
No
Go to the next step.
9
INSPECT POWER SUPPLY TERMINAL AT IGNITION COIL CONNECTOR
• Disconnect ignition coil connector.
• Turn the ignition switch to the ON position (Engine off).
• Measure the voltage between ignition coil terminal D (wiring harness-side) and body ground.
• Is the voltage B+?
Yes
Go to the next step.
No
Check for open circuit between the ignition coil connector and ignition switch. Repair or replace the wiring harness, then go to Step 21.
10
INSPECT IGNITION COIL RESISTANCE
• Inspect ignition coil resistance.
• Is the coil resistance normal?
Yes
Go to step 21.
No
Replace the ignition coil, then go to Step 21.
11
INSPECT MAF PID
• Start the engine.
• Access MAF PID using WDS or equivalent.
• Verify that MAF PID changes quickly according to race engine RPM.
• Is MAF PID response normal?
Yes
Go to the next step.
No
Replace the MAF sensor, then go to Step 21.
12
INSPECT EXCESSIVE AIR SUCTION IN INTAKE AIR SYSTEM
• Inspect for air leakage at following:
- Between mass air flow sensor and throttle body
- Between throttle body and dynamic chamber
• Is there any malfunction?
Yes
Repair or replace the part, then go to Step 21.
No
Go to the next step.
13
INSPECT FUEL LINE PRESSURE
• Inspect fuel line pressure.
• Is fuel line pressure normal?
Yes
Go to step 17.
No
If fuel line pressure is too low, go to the next step.
If fuel line pressure is excess high, check as follows:
• Fuel pump maximum pressure
• Fuel return line for clogged
- If all above are normal, replace the pressure regulator.
Then go to Step 21.
14
INSPECT FUEL PUMP MAXIMUM PRESSURE
• Inspect fuel pump maximum pressure.
• Is fuel pump maximum pressure normal?
Yes
Go to the next step.
No
Inspect fuel pump circuit for open or poor connection. Repair or replace the circuit, then go to Step 21.
• If normal, replace the fuel pump, then go to Step 21.
15
INSPECT FUEL LINE FROM FUEL PUMP TO FUEL DELIVERY PIPE
• Visually inspect for fuel leakage in fuel line for any leakage.
• Is any fuel leakage found?
Yes
Replace the fuel line, then go to Step 21.
No
Inspect fuel filters for the following:
• Restriction or clogging at the fuel filter (high-pressure side).
• Foreign materials or stain inside the fuel filter (low-pressure side)
Perform the following actions as result.
• If restriction or clogging is found at the fuel filter (high-pressure side), replace fuel filter.
• If foreign materials or the stain is found inside the fuel filter (low-pressure side), clean off the fuel tank and filter.
• If all items above are normal, replace the pressure regulator.
Then, go to Step 21.
16
INSPECT ENGINE COMPRESSION
• Inspect engine compression.
• Is it normal?
Yes
Go to the next step.
No
Implement engine overhaul for repairs, then go to Step 21.
17
INSPECT OPERATION OF PURGE CONTROL SOLENOID VALVE
• Perform purge solenoid valve inspection.
• Is the purge control solenoid valve normal?
Yes
Go to the next step.
No
Replace the purge control solenoid valve, then go to Step 21.
18
INSPECT PCV VALVE OPERATION
• Turn the ignition switch off.
• Remove the PCV valve and check valve operation.
• Is the PCV valve operation normal?
Yes
Replace the PCV valve, then go to Step 21.
No
Go to the next step.
19
INSPECT OPERATION OF EGR VALVE
• Remove the EGR valve.
• Visually inspect for stuck to open.
• Does the EGR valve stuck to open?
Yes
Go to the next step.
No
Repair or replace the EGR valve, then go to Step 21.
20
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 the 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 the malfunctioning parts, then go to the next step.
No
Go to the next step.
21
VERIFY TROUBLESHOOTING OF MISFIRE DTC COMPLETED
• Make sure to reconnect all disconnected connectors.
• Turn the ignition switch to the ON position (Engine off).
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Run PCM adaptive memory procedure drive mode.
• Is the PENDING CODE of same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
22
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.