P0306
The content of this article reflects the changes identified in TSB - 10-13-007.DTC P0306 Cylinder 6 Misfire Detected
Misfire Detected Circuit
- Refer to DTC P0201, P0203, P0205 - Injector Circuit.
- Refer to DTC P0202, P0204, P0206 - Injector Circuit.
CIRCUIT OPERATION
- Refer to DTC P0201, P0203, P0205 - Injector Circuit.
- Refer to DTC P0202, P0204, P0206 - Injector Circuit.
TECHNICAL DESCRIPTION
- If a misfire occurs while the engine is running, the engine speed changes for an instant.
- The ECM
DESCRIPTIONS OF MONITOR METHODS
Monitor angular acceleration of crankshaft and detect malfunction when negative variation of the angular acceleration is large.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored )
- Not applicable
Sensor (The sensor below is determined to be normal)
- Camshaft position sensor
- Volume airflow sensor
- Engine coolant temperature sensor
- Intake air temperature sensor
- Barometric pressure sensor
- Throttle position sensor
DTC SET CONDITIONS
Logic Flow Chart:
Logic Flow Chart
Check Conditions
- Engine speed is between 440 and 6,000 r/min.
- Engine coolant temperature is higher than -10 °C (14 °F).
- Intake air temperature is higher than -10 °C (14 °F).
- Barometric pressure is higher than 76 kPa (11 psi).
- Volumetric efficiency is at between 30 and 60 percent.
- Adaptive learning is complete for the vane which generates a crankshaft position signal.
- While the engine is running, excluding gear shifting, deceleration, sudden acceleration/deceleration and A/C compressor switching.
- The throttle deviation is -0.059 v/10 ms to +0.059 v/10 ms.
Judgement Criteria (change in the angular acceleration of the crankshaft is used for misfire detection).
- Misfire has occurred more frequently than allowed during the last 200 revolutions [when the catalyst temperature is higher than 950 °C (1,742 °F)].
or
- Misfire has occurred in 20 or more of the last 1,000 revolutions (corresponding to 1.5 times the limit of emission standard).
OBD-II DRIVE CYCLE PATTERN
Refer to, Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Fuel aeration due to low fuel level.
- Ignition system related part (s) failed.
- Low compression pressure.
- Injector failed.
- ECM failed.
- PCM failed.
- Spark plug failed.
- Harness damage in injector circuit, or connector damage.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
Check whether fuel may be aerated due to low fuel level.
^ Check whether users have experienced the lack of fuel or not.
Q: Has the user ever experienced the lack of fuel?
YES: Ensure fuel level is not low, erase the DTC, and re-evaluate for misfire condition using the appropiate OBD-II Drive Cycle Procedure.
NO: Go to Step 1.
STEP 1. Check the spark plugs.
CAUTION: Do not attempt to adjust the gap of the platinum plug. Cleaning of the platinum plug may result in damage to the platinum tips. Therefore, if carbon deposits must be removed, use a plug cleaner and complete cleaning within 20 seconds to protect the electrode. Do not use a wire brush.
1. For the right bank cylinder, remove the intake manifold.
2. Check the plug gap and replace if the limit is exceeded.
Standard value: 1.0 - 1.1 mm (0.039 - 0.043 inch)
Limit: 1.3 mm (0.051 inch)
Q: Is the plug gap at the standard value?
YES: Go to Step 2.
NO: Replace the spark plug. Then go to Step 9.
STEP 2. Check the spark plug cable.
1. Check the cap and coating for cracks.
2. Measure the resistance.
Limit: maximum 22 kOhms
Q: Is the measured resistance less than 22 kOhms?
YES: Go to Step 3.
NO: Replace the spark plug cable. Then go to Step 9.
STEP 3. Check the injector.
1. Disconnect the injector connector B-01
2. Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]
Q: Is the resistance between 13 and 16 Ohms ?
YES: Go to Step 4.
NO: Replace the injector. Then go to Step 9.
STEP 4. Check connector at injector and injector intermediate connector for damage.
a. Check the connector B-01 at injector and connector B-48 at injector intermediate connector when checking No. 1 cylinder.
b. Check the connector B-02 at injector when checking No. 2 cylinder.
c. Check the connector B-05 at injector and connector B-48 at injector intermediate connector when checking No. 3 cylinder.
d. Check the connector B-06 at injector when checking No. 4 cylinder.
e. Check the connector B-26 at injector and connector B-48 at injector intermediate connector when checking No. 5 cylinder.
f. Check the connector B-25 at injector when checking No. 6 cylinder.
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace the injector. Refer to Harness Connector Inspection. Then go to Step 9.
STEP 5. Check connector C-51 at ECM
Q: Is the connector in good condition?
YES: Go to Step 6.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 9.
STEP 6. Check for harness damage between injector connector and ECM connector
a. Check the harness wire between injector connector B-01 (terminal No. 2) and ECM connector C-51 (terminal No. 1)
b. Check the harness wire between injector connector B-02 (terminal No. 2) and ECM connector C-51 (terminal No. 9)
c. Check the harness wire between injector connector B-05 (terminal No. 2) and ECM connector C-51 (terminal No. 24)
d. Check the harness wire between injector connector B-06 (terminal No. 2) and ECM connector C-51 (terminal No. 2)
e. Check the harness wire between injector connector B-26 (terminal No. 2) and ECM connector C-51 (terminal No. 10)
f. Check the harness wire between injector connector B-25 (terminal No. 2) and ECM connector C-51 (terminal No. 25)
Q: Is the harness wire in good condition?
YES: Go to Step 7.
NO: Repair it. Then go to Step 9.
STEP 7. Check the compression.
Refer to On-Vehicle Service - Compression Pressure Check.
Q: Are there any abnormalities?
YES: Go to Step 8.
NO: Repair or replace it. Then go to Step 9.
STEP 8. Replace the injector.
1. Replace the injector.
2. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
3. Check the diagnostic trouble code (DTC).
Q: Are DTC P0301, P0302, P0303, P0304, P0305 and P0306 sets?
YES: Replace the ECM or PCM. Then go to Step 9.
NO: The inspection is complete.
STEP 9. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor. OBD-II Drive Cycle Pattern Lists
2. Check the diagnostic trouble code (DTC).
Q: Are DTC P0301, P0302, P0303, P0304, P0305 and P0306 sets?
YES: Retry the troubleshooting.
NO: The inspection is complete.