Dtc P0300 Random / Multiple Cylinder Misfire Detected

DESCRIPTION

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE DTCS)

READ VALUE USING INTELLIGENT TESTER (MISFIRE RPM AND MISFIRE LOAD)

CHECK PCV HOSE (HOSE CONNECTIONS)

CHECK MISFIRE COUNT (CYLINDER #1, #2, #3, #4, #5 AND #6)

CHECK SPARK PLUG

CHECK FOR SPARKS AND IGNITION

CHECK CYLINDER COMPRESSION PRESSURE (MALFUNCTION CYLINDER)

CHANGE SPARK PLUG WITH NORMAL ONE AND CHECK FOR SPARKS OF MISFIRING CYLINDER

INSPECT ECM (#10, #20, #30, #40, #50 AND/OR #60 VOLTAGE))

CHECK HARNESS AND CONNECTOR (INJECTOR - ECM)

CHECK FUEL INJECTOR ASSEMBLY (MISFIRING CYLINDER)

CHECK AIR INDUCTION SYSTEM

CHECK VALVE TIMING

CHECK FUEL PRESSURE

READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

READ VALUE USING INTELLIGENT TESTER (MAF)

CHECK MISFIRE COUNT (CYLINDER #1, #2, #3, #4, #5 AND #6)

DESCRIPTION

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

1. Connect the intelligent tester to the DLC3.
   
2. Turn the ignition switch to the ON position.
   
3. Turn the tester on.
   
4. Record the DTC(s) and freeze frame data.
   
5. Using the tester, switch the ECM from normal mode to check mode (RAV4_ACA30 RM000000PDL09GX.html).
   
6. Read the misfire counts of each cylinder (CYL #10 to #60) with the engine in an idling condition. If any misfire count is displayed, skip the following confirmation driving pattern.
   
7. Drive the vehicle several times with the conditions, such as engine rpm and engine load, shown in Misfire PRM and Misfire Load in the Data List.
   
   

   HINT:

   In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below, using the Misfire PRM and Misfire Load in the Data List.

   
   

   Engine RPM	Duration
   Idling	3.5 minutes or more
   1000	3 minutes or more
   2000	1.5 minutes or more
   3000	1 minute or more

8. Check whether misfires have occurred by checking DTCs and freeze frame data.
   

   HINT:

   Do not turn the ignition switch off until the stored DTC(s) and freeze frame data have been recorded. When the ECM returns to normal mode (default), the stored DTC(s), freeze frame data and other data will be erased.

9. Record the DTC(s), freeze frame data and misfire counts.
   
10. Turn the ignition switch off and wait for at least 5 seconds.
    

INSPECTION PROCEDURE

HINT:

1. If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
   
2. Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (RAV4_ACA30 RM000000PDS09FX.html).
   
3. If the misfire does not recur when the vehicle is brought to the workshop, reproduce the conditions stored in the ECM as freeze frame data.
   
4. If the misfire still cannot be reproduced even though the conditions stored in the ECM as freeze frame data have been reproduced, one of the following factors is considered to be a possible cause of the problem:
   
1. There was insufficient fuel in the tank.
   
2. Improper fuel is used.
   
3. The spark plugs have been contaminated.
   
4. The problem requires further diagnosis.
   
5. After finishing repairs, check the misfire counts of the cylinders (Cylinder #1, #2, #3, #4, #5 and #6).
   
6. Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern after finishing repairs.
   
7. For 6 and 8 cylinder engines, the ECM intentionally does not set the specific misfiring cylinder DTCs at high engine RPM. If misfires occur only in high engine RPM areas, only DTC P0300 is set.
   In the event of DTC P0300 being present, perform the following operations:
   
1. Clear the DTC (RAV4_ACA30 RM000000PDK0AIX.html).
   
2. Start the engine and conduct the confirmation driving pattern.
   
3. Read the misfiring rates of each cylinder or DTC(s) using the tester.
   
4. Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
   
5. After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC P0300 is not set.
   
8. When one of Short FT #1, Long FT #1, Short FT #2 or Long FT #2 in the freeze frame data is outside the range of +/-20 %, the air-fuel ratio may be RICH (-20 % or less) or LEAN (+20 % or more).
   
9. When the Coolant Temp in the freeze frame data is less than 75°C (167°F), the misfire have occurred only while warming up the engine.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position.
   

3. Turn the tester on.
   

4. Enter the following menus: Powertrain / Engine and ECT / DTC.
   

5. Read the DTCs.
   
   

   Result:

   
   

   Display (DTC output)	Proceed to
   P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306	A
   P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 and other DTCs	B

HINT:

If any DTCs other than P0300, P0301, P0302, P0303, P0304, P0305 and P0306 are output, troubleshoot those DTCs first.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position and turn the tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Data List / Misfire RPM and Misfire Load.
   

4. Read and note the Misfire RPM and Misfire Load (engine load) values.
   

   HINT:

   The Misfire RPM and Misfire Load values indicate the vehicle conditions under which the misfire occurred.

OK:

PCV hose is connected correctly and is not damaged.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position.
   

3. Turn the tester on.
   

4. Clear the DTCs.
   

5. Enter the following menus: Powertrain / Engine and ECT / Data List / Cylinder #1, #2, #3, #4, #5 and #6 Misfire rate (Step "A").
   

6. Allow the engine to idle (Step "B").
   

7. Read the value of Cylinder #1 to #6 displayed on the tester. If no misfire counts occur in any cylinders, perform the following operations (Step "C"):
   

   1. Shift the gear selector lever to the D position.
      

   2. Repeat steps "A" to "C" above.
      

   3. Check the Cylinder #1 to #6.
      

   4. If misfire counts are still not displayed, perform steps "D" and "E" and then check the misfire counts again.
      

8. Drive the vehicle with the Misfire RPM and Misfire Load noted in step 2 (Step "D").
   

9. Read the Cylinder #1 to #6 or DTCs displayed on the tester (Step "E").
   
   

   Result:

   
   

   Misfire count	Proceed to
   1 or 2 cylinders have misfire counts	A
   3 cylinders or more have misfire counts	B

1. Remove the ignition coil and the spark plug of the misfiring cylinder.
   

2. Measure the spark plug electrode gap.
   

   Standard:

   Between 1.0 mm and 1.4 mm (0.039 in. and 0.055 in.)
   

3. Check the electrode for carbon deposits.
   

   Recommended spark plug:

   Manufacturer	Product
   DENSO	FK20HR11

   NOTICE:

   If the electrode gap is larger than the standard, replace the spark plug. Do not adjust the electrode gap.

1. Disconnect the injector connectors, in order to prevent the engine from starting.
   

2. Install the spark plug to the ignition coil.
   

3. Attach the spark plug assembly to the cylinder head cover.
   

4. Crank the engine for less than 2 seconds and check the sparks.
   

   OK:

   Sparks jump across the electrode gap.
   

5. Reconnect the injector connectors.
   

1. Measure the cylinder compression pressure of the misfiring cylinder.
   

1. Change the installed spark plug with a spark plug that functions normally.
   

2. Perform a spark test.
   

   CAUTION:

   Always disconnect each injector connector.

   NOTICE:

   Do not crank the engine for more than 2 seconds.

   1. Install the spark plug to the ignition coil and connect the ignition coil connector.
      

   2. Disconnect the injector connector.
      

   3. Ground the spark plug.
      

   4. Check if sparks occur while the engine is being cranked.
      

      OK:

      Sparks jump across the electrode gap.
      

1. Disconnect the ECM connector.
   

2. Turn the ignition switch to the ON position.
   

3. Measure the voltage between the terminals.
   

   Standard voltage:

   Tester Connection	Specified Condition
   #10 (B96-45) - E01 (B96-22)	9 to 14 V
   #20 (B96-85) - E01 (B96-22)	9 to 14 V
   #30 (B96-44) - E01 (B96-22)	9 to 14 V
   #40 (B96-84) - E01 (B96-22)	9 to 14 V
   #50 (B96-43) - E01 (B96-22)	9 to 14 V
   #60 (B96-83) - E01 (B96-22)	9 to 14 V

4. Reconnect the ECM connector.
   

1. Disconnect the injector connector (misfire cylinder).
   

2. Disconnect the ECM connector.
   

3. Measure the resistance between the terminals.
   

   Standard resistance (Check for open):

   Tester Connection	Specified Condition
   #10 (B96-45) - B87-1	Below 1 Ω
   #20 (B96-85) - B71-1	Below 1 Ω
   #30 (B96-44) - B86-1	Below 1 Ω
   #40 (B96-84) - B70-1	Below 1 Ω
   #50 (B96-43) - B85-1	Below 1 Ω
   #60 (B96-83) - B69-1	Below 1 Ω

   Standard resistance (Check for short):

   Tester Connection	Specified Condition
   #10 (B96-45) or B87-1 - Body ground	10 kΩ or higher
   #20 (B96-85) or B71-1 - Body ground	10 kΩ or higher
   #30 (B96-44) or B86-1 - Body ground	10 kΩ or higher
   #40 (B96-84) or B70-1 - Body ground	10 kΩ or higher
   #50 (B96-43) or B85-1 - Body ground	10 kΩ or higher
   #60 (B96-83) or B69-1 - Body ground	10 kΩ or higher

4. Reconnect the injector connector.
   

5. Reconnect the ECM connector.
   

1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).
   

1. Check the air induction system for vacuum leakage.
   

   OK:

   No leakage from air induction system.
   

1. Remove the cylinder head covers.
   

2. Turn the crankshaft pulley, and align its groove with the timing mark "0" of the timing chain cover.
   

3. Check that the timing marks of the camshaft timing gears are aligned with the timing marks of the bearing cap as shown in the illustration.
   If not, turn the crankshaft 1 revolution (360°) and align the marks as above.
   

   OK:

   Timing marks on the camshaft timing gears are aligned as shown in illustration.
   

4. Reinstall the cylinder head covers.
   

1. Check the fuel pressure.
   

   Standard:

   Item	Standard Condition
   Fuel pressure	304 to 343 kPa (3.1 to 3.5 kgf/cm2, 44 to 50 psi)

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position.
   

3. Turn the tester on.
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
   

5. Read the Coolant Temp twice, when the engine is both cold and warmed up.
   

   Standard:

   With cold engine:

   Same as ambient air temperature.
   

   With warm engine:

   Between 75°C and 95°C (167°F and 203°F).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to the ON position.
   

3. Turn the tester on.
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / Coolant Temp.
   

5. Allow the engine to idle until the Coolant Temp reaches 75°C (167°F) or more.
   

6. Read the MAF with the engine in an idling condition and at an engine speed of 2500 rpm.
   

   Standard:

   MAF when engine is stopped:

   Below 0.7 g/s
   

   MAF while engine is idling:

   Between 2.0 g/s and 5.0 g/s (shift position: N, A/C: OFF).
   

   MAF at an engine speed of 2500 rpm:

   Between 8.0 g/s and 19.0 g/s (shift position: N, A/C: OFF).
   

HINT:

1. If the result of step 4 is "1 or 2 cylinders", proceed to A.
   
2. If the result of step 4 is "more than 3 cylinders", proceed to B.