Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Random/Multiple Cylinder Misfire Detected (P030000,P030027,P030085-P030600)

DESCRIPTION

When the engine misfires, high concentrations of hydrocarbons (HC) enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause an increase in exhaust emission levels. Extremely high concentrations of hydrocarbons can also cause increases in the three-way catalytic converter temperature, which may cause damage to the three-way catalytic converter. To prevent this increase in emissions and to limit the possibility of thermal damage, the ECM monitors the misfire count. When the temperature of the three-way catalytic converter reaches the point of thermal degradation, the ECM blinks the MIL. To monitor misfires, the ECM uses both the VVT sensor and the crankshaft position sensor. The VVT sensor is used to identify any misfiring cylinders and the crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted when the crankshaft rotation speed variations exceed predetermined thresholds. If the misfire count exceeds the threshold levels, and could cause emission control system performance deterioration, the ECM illuminates the MIL and stores a DTC.

When DTCs for misfiring cylinders are randomly stored, but DTC P030000 is not stored, it indicates that misfires have been detected in different cylinders at different times. DTC P030000 is only stored when several misfiring cylinders are detected at the same time.

MONITOR DESCRIPTION

The ECM illuminates the MIL and stores a DTC when either one of the following conditions, which could cause emission deterioration, is detected (2 trip detection logic).

• Within the first 1000 crankshaft revolutions after the engine starts, an excessive number of misfires (approximately 50 to 100 misfires per 1000 crankshaft revolutions) occurs once.
• An excessive number of misfires (approximately 50 to 100 misfires per 1000 crankshaft revolutions) occurs a total of 4 times.

The ECM flashes the MIL (immediate detection logic) and stores a DTC (2 trip detection logic) when either one of the following conditions, which could cause damage to the three-way catalytic converter, is detected.

• At a high engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected once.
• At a normal engine speed, a sufficient amount of misfires to damage the catalyst occurring within 200 crankshaft revolutions is detected 3 times.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

MONITOR RESULT

Refer to detailed information in Checking Monitor Status.

Click here

HINT:

*: EWMA (Exponential Weighted Moving Average) misfire counts for last 10 driving cycles (calculated) Calculation: 0.1 x (current counts) + 0.9 x (previous average)

Initial value for (previous average) = 0

CONFIRMATION DRIVING PATTERN

HINT:

• When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

  Click here

• Permanent misfire and fuel system DTCs can only be cleared when performing the universal trip driving pattern when no malfunction is detected.

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Record the DTC(s) and Freeze Frame Data.
5. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
6. Using the Techstream, switch the ECM from normal mode to check mode.

   Click here

7. Start the engine.
8. Read the misfire counts of each cylinder, Misfire Count Cylinder #1 to Misfire Count Cylinder #6, with the engine idling. If any misfire count is displayed, skip the following confirmation driving pattern.
9. Drive the vehicle so that the vehicle conditions displayed in Misfire RPM and Misfire Load of the Data List are the same as the freeze frame data. Perform this step several times.

   HINT:

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

   Engine speed	Duration
   Idling	8.0 minutes or more
   1000	4.5 minutes or more
   2000	2.5 minutes or more
   3000	1.5 minutes or more

10. Check whether misfires have occurred by checking DTCs and Freeze Frame Data.

    HINT:

    Do not turn the engine switch off until the output 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 are cleared.

11. Record the DTC(s), freeze frame data and misfire counts.
12. Turn the engine switch off and wait for at least 30 seconds.
13. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

WIRING DIAGRAM

Refer to DTC P010012 for the mass air flow meter sub-assembly circuit.

Click here

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

• If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
• Check the "Fuel Cut Elapsed Time" in the Data List or the Freeze Frame Data.

  If the elapsed time is over 0 seconds, then the engine speed is high (engine speed at which fuel cut occurs + 500 rpm).

  When this has happened, there is the possibility that the No. 1 valve rocker arm sub-assembly will become loose and a fire could start, so check that the No. 1 valve rocker arm sub-assembly is properly attached.

• By clearing the DTCs, "Fuel Cut Elapsed Time" will be cleared.
• 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.
• 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 was used.
  3. The spark plugs have been contaminated.
  4. The problem requires further diagnosis.
• After finishing repairs, check the misfire counts of the cylinders (Misfire Count Cylinder #1 to Misfire Count Cylinder #6).
• Be sure to confirm that no misfiring cylinder DTCs are stored again by performing the confirmation driving pattern after finishing repairs.
• For 6 cylinder engine, the ECM intentionally does not set the specific misfiring cylinder DTCs at high engine speed. If misfires occur only in high engine speed areas, only DTC P030000 is set.

  In the event of DTC P030000 being present, perform the following operations:

  1. Clear the DTCs.

     Click here

  2. Start the engine and conduct the confirmation driving pattern.
  3. Read the misfire count of each cylinder or DTC(s) using the Techstream.
  4. Repair the cylinder(s) that has a high misfiring count or is indicated by the DTC.
  5. After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC P030000 is not set.
• When one of Short FT B1S1, Long FT B1S1, Short FT B2S1 or Long FT B2S1 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 higher).
• When Coolant Temperature in the freeze frame data is less than 75°C (167°F), the misfires have occurred only while warming up the engine.
• Vehicle body vibration caused by an extremely imbalanced drive wheel may cause misfire DTCs to be stored.
• Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read the DTCs.

HINT:

If any DTCs other than P030000, P030027, P030085, P030100, P030200, P030300, P030400, P030500 and/or P030600 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART

A

(a) Check the PCV hose connections.

Click here

OK:

PCV valve and hose are correctly connected and are not damaged.

NG

REPAIR OR REPLACE PCV HOSE

OK

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Misfire RPM and Misfire Load.

(e) Read and note the Misfire RPM and Misfire Load values.

HINT:

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

NEXT

(a) Enter the following menus: Powertrain / Engine / Data List / Catalyst OT Misfire Fuel Cut.

(b) Read the value displayed on the Techstream.

B

GO TO STEP 6

A

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Active Test / Prohibit the Catalyst OT Misfire Prevent Fuel Cut.

(e) Perform the Active Test.

NOTICE:

When performing the Active Test, make sure the vehicle is stopped and the engine is either idling or being revved within 3000 rpm.

NEXT

(a) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

(b) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Mode / Port / Data List / Coolant Temperature, Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6.

(c) According to the display on the Techstream, read the Data List with the Active Test "Control the Injection Mode" set to Port. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

(1) Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using Techstream (Misfire RPM and Misfire Load)" procedures above [A].

(2) Read the Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6 or DTCs displayed on the Techstream [B].

B

GO TO STEP 10

A

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Mode / Direct / Data List / Coolant Temperature, Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6.

(f) According to the display on the Techstream, read the Data List with the Active Test "Control the Injection Mode" set to Direct. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

(1) Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using Techstream (Misfire RPM and Misfire Load)" procedures above [A].

(2) Read the Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6 or DTCs displayed on the Techstream [B].

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly (for port injection).

Click here

A

GO TO STEP 13

B

GO TO STEP 16

C

REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION (MISFIRING CYLINDER))

D

(a) Check the fuel pressure (for low pressure side).

Click here

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly (for port injection).

Click here

OK

REPLACE FUEL INJECTOR ASSEMBLY (FOR PORT INJECTION (MISFIRING CYLINDER))

NG

(a) Check the fuel pump operation (for low pressure side).

Click here

OK

CHECK AND REPLACE FUEL SYSTEM

NG

GO TO FUEL PUMP CONTROL CIRCUIT

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Mode / Direct / Data List / Coolant Temperature, Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6.

(f) According to the display on the Techstream, read the Data List with the Active Test "Control the Injection Mode" set to Direct. If no misfire counts occur in any cylinders, perform procedure [A] and [B] and then check the misfire counts again.

(1) Drive the vehicle with the Misfire RPM and Misfire Load noted in the "Read Value Using Techstream (Misfire RPM and Misfire Load)" procedures above [A].

(2) Read the Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6 or DTCs displayed on the Techstream [B].

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly (for direct injection).

Click here

A

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION)

B

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

(e) Turn the engine switch off and wait for at least 30 seconds.

NEXT

(a) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

(b) Turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature, Injection Mode, Misfire Count Cylinder #1 to Misfire Count Cylinder #6, Misfire RPM and Misfire Load.

(d) Drive the vehicle with Misfire RPM and Misfire Load.

(e) Monitor all of the misfire count values or DTCs and Injection Mode displayed on the Techstream.

HINT:

Perform "Inspection After Repair" after replacing the fuel injector assembly (for direct injection).

Click here

A

CHECK FOR INTERMITTENT PROBLEMS

C

GO TO STEP 16

D

REPLACE FUEL INJECTOR ASSEMBLY (FOR DIRECT INJECTION)

B

(a) Inspect the spark plug of the misfiring cylinder.

Click here

HINT:

Perform "Inspection After Repair" after replacing the spark plug.

Click here

NG

REPLACE SPARK PLUG

OK

(a) Perform a spark test.

Click here

HINT:

• If the result of the spark test is normal, proceed to the next step.
• Perform "Inspection After Repair" after replacing the spark plug or ignition coil assembly.

  Click here

NEXT

(a) Measure the cylinder compression pressure of the misfiring cylinder.

Click here

HINT:

Perform "Inspection After Repair" after repairing or replacing the engine assembly.

Click here

OK

REPLACE ECM

NG

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

(a) Check the intake system for vacuum leaks.

Click here

OK:

No leaks in intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

Click here

NG

REPAIR OR REPLACE INTAKE SYSTEM

OK

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Coolant Temperature.

(e) Read the Data List twice, when the engine is both cold and warmed up.

Standard:

HINT:

Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.

Click here

NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR

OK

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Mass Air Flow Sensor and Coolant Temperature.

(e) Allow the engine to idle until Coolant Temperature reaches 75°C (167°F) or higher.

(f) Read Mass Air Flow Sensor while maintaining an engine speed of 3000 rpm.

Standard:

NG

GO TO STEP 23

OK

(a) Remove the cylinder head cover sub-assembly and cylinder head cover sub-assembly LH.

(b) Turn the crankshaft pulley and align its groove with the TDC timing mark of the timing chain cover.

(c) Check that the timing marks of the camshaft timing gear assemblies and camshaft timing exhaust gear assemblies are aligned with the timing marks of the bearing cap as shown in the illustration.

HINT:

If the timing marks are not as shown, turn the crankshaft one revolution clockwise.

OK:

Timing marks on camshaft timing gear assemblies and camshaft timing exhaust gear assemblies are aligned as shown in the illustration.

HINT:

If the result is not as specified, check for mechanical malfunctions that may have affected the valve timing, such as a jumped tooth or stretching of the timing chain.

OK

GO TO STEP 23

NG

(a) Check for mechanical malfunctions that affect the valve timing, such as a jumped tooth or stretching of the timing chain.

HINT:

Perform "Inspection After Repair" after repairing or replacing the engine mechanical system.

Click here

NG

REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

OK

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

(e) Turn the engine switch off and wait for at least 30 seconds.

NEXT

(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(b) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(c) Input the DTC: P030000, P030027, P030085, P030100, P030200, P030300, P030400, P030500 or P030600.

(d) Check the DTC judgment result.

A

CHECK FOR INTERMITTENT PROBLEMS

B

GO TO STEP 23

(a) Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

Click here

HINT:

Repair any problems.

NEXT

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

(e) Turn the engine switch off and wait for at least 30 seconds.

NEXT

(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(b) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(c) Input the DTC: P030000, P030027, P030085, P030100, P030200, P030300, P030400, P030500 or P030600.

(d) Check the DTC judgment result.

A

END

B

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Replace the mass air flow meter sub-assembly.

Click here

HINT:

• If the results of the inspections performed in step 17 (READ VALUE USING TECHSTREAM (MASS AIR FLOW SENSOR)) indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
• Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

  Click here

NEXT

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Clear the DTCs.

(e) Turn the engine switch off and wait for at least 30 seconds.

NEXT

(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(b) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(c) Input the DTC: P030000, P030027, P030085, P030100, P030200, P030300, P030400, P030500 or P030600.

(d) Check the DTC judgment result.

A

END

B

REPLACE ECM