DTC P0301:00, P0302:00, P0303:00, P0304:00 [ZJ, ZY]

DTC P0301:00	Cylinder No.1 misfire detected
DETECTION CONDITION	• The PCM monitors the CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, the PCM detects a misfire in the corresponding cylinder. While the engine is running, the PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the 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 above malfunction condition 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 the 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. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Erratic signal to PCM ― Brake switch signal malfunction ― ECT sensor signal malfunction ― IAT sensor signal malfunction ― MAF sensor signal malfunction ― CKP sensor signal malfunction ― TP sensor signal malfunction ― VSS signal malfunction • Ignition system malfunction ― Spark plug malfunction ― Ignition coil and related wiring harness malfunction • Air suction in intake air system (between dynamic chamber and cylinder head) • Fuel injector related wiring harness malfunction • Engine malfunction ― Engine coolant leakage ― Insufficient compression • Improper operation of fuel injector • PCM malfunction

DTC P0301:00

Cylinder No.1 misfire detected

DTC P0302:00

Cylinder No.2 misfire detected

DTC P0303:00

Cylinder No.3 misfire detected

DTC P0304:00

Cylinder No.4 misfire detected

DETECTION CONDITION

• The PCM monitors the CKP sensor input signal interval time. The PCM calculates the change of interval time for each cylinder. If the change of interval time exceeds the preprogrammed criteria, the PCM detects a misfire in the corresponding cylinder. While the engine is running, the PCM counts the number of misfires that occurred at 200 crankshaft revolutions and 1,000 crankshaft revolutions and calculates the misfire ratio for each crankshaft revolution. If the ratio exceeds the preprogrammed criteria, the 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 above malfunction condition 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 the 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.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Erratic signal to PCM

― Brake switch signal malfunction

― ECT sensor signal malfunction

― IAT sensor signal malfunction

― MAF sensor signal malfunction

― CKP sensor signal malfunction

― TP sensor signal malfunction

― VSS signal malfunction

• Ignition system malfunction

― Spark plug malfunction

― Ignition coil and related wiring harness malfunction

• Air suction in intake air system (between dynamic chamber and cylinder head)

• Fuel injector related wiring harness malfunction

• Engine malfunction

― Engine coolant leakage

― Insufficient compression

• Improper operation of fuel injector

• PCM malfunction

STEP	INSPECTION	ACTION
1	VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED • Have the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (misfire related) been recorded?	Yes	Go to the next step.
No	Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND STORED DTC • Turn the ignition switch off, then to the ON position (engine off). • Verify the related PENDING CODE and stored DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [ZJ, ZY].) • Are any other DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [ZJ, ZY].)
No	Go to the next step.
4	VERIFY CURRENT INPUT SIGNAL STATUS (IGNITION SWITCH TO ON/IDLE) • Perform the PID/DATA Monitor and Record Procedure and access the following PIDs: (See ON-BOARD DIAGNOSTIC TEST [ZJ, ZY].) ― BOO ― ECT ― IAT ― MAF ― RPM ― TP REL ― VSS • Is there any signal that is far out of specification when ignition switch is the ON position and the engine runs at idle? (See PCM INSPECTION [ZJ, ZY].)	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.
No	Go to the next step.
5	VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA CONDITION • Perform the PID/DATA Monitor and Record Procedure and access the same PIDs as in Step 4 under the FREEZE FRAME DATA. (See ON-BOARD DIAGNOSTIC TEST [ZJ, ZY].) • Is there any signal which causes drastic changes?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.
No	Go to the next step.
6	INSPECT SPARK PLUG CONDITION • Turn the ignition switch off. • Remove the spark plug from suspected cylinder. (See SPARK PLUG REMOVAL/INSTALLATION [ZJ, ZY].) • Inspect the spark plug condition: ― Cracks ― Excess wear ― Gap ― Wet • Is there any malfunction?	Yes	Go to the next step.
No	If the spark plug is wet: • Fuel flooding is suspected. ― Go to Step 13. If the spark plug has a cracks, excessive wear or improper gap: • Replace the suspected spark plug, then go to Step 13. (See SPARK PLUG REMOVAL/INSTALLATION [ZJ, ZY].)
7	INSPECT IGNITION COIL AND RELATED WIRING HARNESS • Inspect the ignition coil and related wiring harness condition (intermittent open or short circuit) for all cylinders. (See IGNITION COIL INSPECTION [ZJ, ZY].) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 13. (See IGNITION COIL REMOVAL/INSTALLATION [ZJ, ZY].)
No	Go to the next step.
8	INSPECT FOR AIR SUCTION AT INTAKE-AIR SYSTEM • Inspect for air leakage at the following: ― Around connection of dynamic chamber and intake manifold ― Around connection of intake manifold and cylinder head Note • Engine speed may change when rust penetrating agent is sprayed on the air suction area. • Is there air leakage?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.
No	Go to the next step.
9	INSPECT FUEL INJECTOR RELATED WIRING HARNESS • Remove the intake air system parts. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [ZJ, ZY].) • Disconnect the fuel injector connector on suspected cylinder. • Connect the noid light to the fuel injector connector terminals. • Inspect dim of light during cranking. • Does the noid light illuminate?	Yes	Go to the next step.
No	Inspect the fuel injector related wiring harness. Repair or replace the suspected wiring harness, if necessary. Go to Step 13.
10	INSPECT SEALING OF ENGINE COOLANT PASSAGE • Perform the “ENGINE COOLANT LEAKAGE INSPECTION”. (See ENGINE COOLANT LEVEL INSPECTION [ZJ, ZY].) • Is there any malfunction?	Yes	Repair or replace malfunctioning part according to inspection result, then go to Step 13.
No	Go to the next step.
11	INSPECT ENGINE COMPRESSION • Inspect the engine compression. (See COMPRESSION INSPECTION [ZJ, ZY].) • Is there any malfunction?	Yes	Perform the engine overhaul for repairs, then go to Step 13.
No	Go to the next step.
12	INSPECT FUEL INJECTOR OPERATION • Remove the fuel injector from suspected cylinder. (See FUEL INJECTOR REMOVAL/INSTALLATION [ZJ, ZY].) • Switch the injector with injector on other cylinder. • Start the engine and run it at idle. • Is the misfire DTC for cylinder which has a suspected fuel injector?	Yes	Replace the fuel injector, then go to the next step. (See FUEL INJECTOR REMOVAL/INSTALLATION [ZJ, ZY].)
No	Go to the next step.
13	VERIFY DTC TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See AFTER REPAIR PROCEDURE [ZJ, ZY].) • Perform the Drive Mode 01 (PCM Adaptive Memory Produce Drive Mode). (See OBD DRIVE MODE [ZJ, ZY].) • Is the same PENDING CODE or DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [ZJ, ZY].)
No	Go to the next step.
14	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [ZJ, ZY].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [ZJ, ZY].)
No	DTC troubleshooting completed.

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED

• Have the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (misfire related) been recorded?

Yes

Go to the next step.

Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.

VERIFY RELATED SERVICE INFORMATION AVAILABILITY

• Verify related Service Information availability.

• Is any related Service Information available?

Yes

Perform repair or diagnosis according to the available Service Information.

• If the vehicle is not repaired, go to the next step.

Go to the next step.

VERIFY RELATED PENDING CODE AND STORED DTC

• Turn the ignition switch off, then to the ON position (engine off).

• Verify the related PENDING CODE and stored DTCs using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [ZJ, ZY].)

• Are any other DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [ZJ, ZY].)

Go to the next step.

VERIFY CURRENT INPUT SIGNAL STATUS (IGNITION SWITCH TO ON/IDLE)

• Perform the PID/DATA Monitor and Record Procedure and access the following PIDs:

(See ON-BOARD DIAGNOSTIC TEST [ZJ, ZY].)

― BOO

― ECT

― IAT

― MAF

― RPM

― TP REL

― VSS

• Is there any signal that is far out of specification when ignition switch is the ON position and the engine runs at idle?

(See PCM INSPECTION [ZJ, ZY].)

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.

Go to the next step.

VERIFY CURRENT INPUT SIGNAL STATUS UNDER FREEZE FRAME DATA CONDITION

• Perform the PID/DATA Monitor and Record Procedure and access the same PIDs as in Step 4 under the FREEZE FRAME DATA.

(See ON-BOARD DIAGNOSTIC TEST [ZJ, ZY].)

• Is there any signal which causes drastic changes?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.

Go to the next step.

INSPECT SPARK PLUG CONDITION

• Turn the ignition switch off.

• Remove the spark plug from suspected cylinder.

(See SPARK PLUG REMOVAL/INSTALLATION [ZJ, ZY].)

• Inspect the spark plug condition:

― Cracks

― Excess wear

― Gap

― Wet

• Is there any malfunction?

Yes

Go to the next step.

If the spark plug is wet:

• Fuel flooding is suspected.

― Go to Step 13.

If the spark plug has a cracks, excessive wear or improper gap:

• Replace the suspected spark plug, then go to Step 13.

(See SPARK PLUG REMOVAL/INSTALLATION [ZJ, ZY].)

INSPECT IGNITION COIL AND RELATED WIRING HARNESS

• Inspect the ignition coil and related wiring harness condition (intermittent open or short circuit) for all cylinders.

(See IGNITION COIL INSPECTION [ZJ, ZY].)

• Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.

(See IGNITION COIL REMOVAL/INSTALLATION [ZJ, ZY].)

Go to the next step.

INSPECT FOR AIR SUCTION AT INTAKE-AIR SYSTEM

• Inspect for air leakage at the following:

― Around connection of dynamic chamber and intake manifold

― Around connection of intake manifold and cylinder head

Note

• Engine speed may change when rust penetrating agent is sprayed on the air suction area.

• Is there air leakage?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 13.

Go to the next step.

INSPECT FUEL INJECTOR RELATED WIRING HARNESS

• Remove the intake air system parts.

(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [ZJ, ZY].)

• Disconnect the fuel injector connector on suspected cylinder.

• Connect the noid light to the fuel injector connector terminals.

• Inspect dim of light during cranking.

• Does the noid light illuminate?

Yes

Go to the next step.

Inspect the fuel injector related wiring harness.

Repair or replace the suspected wiring harness, if necessary.

Go to Step 13.

INSPECT SEALING OF ENGINE COOLANT PASSAGE

• Perform the “ENGINE COOLANT LEAKAGE INSPECTION”.

(See ENGINE COOLANT LEVEL INSPECTION [ZJ, ZY].)

• Is there any malfunction?

Yes

Repair or replace malfunctioning part according to inspection result, then go to Step 13.

Go to the next step.

INSPECT ENGINE COMPRESSION

• Inspect the engine compression.

(See COMPRESSION INSPECTION [ZJ, ZY].)

• Is there any malfunction?

Yes

Perform the engine overhaul for repairs, then go to Step 13.

Go to the next step.

INSPECT FUEL INJECTOR OPERATION

• Remove the fuel injector from suspected cylinder.

(See FUEL INJECTOR REMOVAL/INSTALLATION [ZJ, ZY].)

• Switch the injector with injector on other cylinder.

• Start the engine and run it at idle.

• Is the misfire DTC for cylinder which has a suspected fuel injector?

Yes

Replace the fuel injector, then go to the next step.

(See FUEL INJECTOR REMOVAL/INSTALLATION [ZJ, ZY].)

Go to the next step.

VERIFY DTC TROUBLESHOOTING COMPLETED

• Make sure to reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

(See AFTER REPAIR PROCEDURE [ZJ, ZY].)

• Perform the Drive Mode 01 (PCM Adaptive Memory Produce Drive Mode).

(See OBD DRIVE MODE [ZJ, ZY].)

• Is the same PENDING CODE or DTC present?

Yes

Replace the PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [ZJ, ZY].)

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform the “AFTER REPAIR PROCEDURE”.

(See AFTER REPAIR PROCEDURE [ZJ, ZY].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [ZJ, ZY].)

DTC troubleshooting completed.