Dtc P0420 Catalyst System Efficiency Below Threshold (Bank 1)

DESCRIPTION

MONITOR DESCRIPTION

INSPECTION PROCEDURE

READ OUTPUT DTC (RECORD STORED DTC AND FREEZE FRAME DATA)

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0420, P244A, P2458 AND P2463)

CHECK BLOCKAGE OF AIR HOSE AND VACUUM PIPE

REPAIR OR REPLACE NO. 1 VACUUM PIPE OR NO. 2 VACUUM PIPE

READ VALUE USING GTS (DPF DIFFERENTIAL PRESSURE)

CONNECT UPSTREAM AIR HOSE

REPLACE DIFFERENTIAL PRESSURE SENSOR

CONNECT DOWNSTREAM AIR HOSE (DOWNSTREAM)

REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY

GO TO DTC CHART

CHECK FOR BLACK SMOKE

REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY

CHECK FOR WHITE SMOKE (DURING PM FORCED REGENERATION)

REPLACE EXHAUST FUEL ADDITION INJECTOR ASSEMBLY

REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY

CHECK FUEL INJECTION SYSTEM

CHECK INTAKE / EXHAUST SYSTEM

CHECK AFTER TREATMENT CONTROL SYSTEM

REPAIR OR REPLACE MALFUNCTIONING PARTS

READ VALUE USING GTS (DPF DIFFERENTIAL PRESSURE)

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DESCRIPTION

HINT:

PM forced regeneration may be prohibited due to a fail-safe operation that is performed when another DTC is stored (including engine output limitation).

MONITOR DESCRIPTION

1. Abnormal DOC catalyst temperature increase:
   The ECM monitors exhaust gas temperature increase while the exhaust fuel addition injector assembly adds fuel during PM forced regeneration. Exhaust gas temperature increases up to approximately 300 to 500°C (572 to 932°F) during PM forced regeneration. If the temperature does not increase even after a certain amount of time has elapsed, the ECM determines that the DOC catalyst is abnormal and illuminates the MIL.
   

1. Catalytic converter differential pressure too low:
   The ECM monitors the DPF catalyst differential pressure when driving and illuminates the MIL when the difference in pressure before and after the catalyst is below the threshold
   

1. Catalytic converter Regeneration Duration:
   When PM forced regeneration is manually performed, PM forced generation does not finish even after 60 minutes or more elapse, the ECM determines that there is problem with the DPF catalyst and illuminates the MIL.
   

1. Excessive PM accumulation:
   The ECM monitors the PM Accumulation Ratio and when the accumulated PM volume in the DPF catalyst exceeds the limit, the ECM illuminates the MIL.
   

INSPECTION PROCEDURE

NOTICE:

1. After replacing the ECM, the new ECM needs registration (LandCruiser RM0000012XK0AUX.html) and initialization (LandCruiser RM000000TIN08HX.html).
   
2. After replacing an injector assembly, the ECM needs registration (LandCruiser RM0000012XK0AUX.html).
   

HINT:

1. If DTC P2458 or P2463 is stored, fail-safe controls engine power output and PM forced regeneration is prohibited. In this case, PM forced regeneration can be performed after disconnecting the EFI-MAIN NO. 1 fuse or battery terminal and waiting for 60 seconds or more before connecting it again.
   
2. Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
   

1. Connect the GTS to the DLC3.
   

2. Turn the engine switch on (IG) and turn the GTS on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
   

4. Record the stored DTC and freeze frame data.
   

5. Check Exhaust Fuel Addition FB and Catalyst Differential Press in the freeze frame data.
   

   HINT:

   1. When the Exhaust Fuel Addition FB value is 1.41 or more, it indicates a high possibility of insufficient temperature increase during PM regeneration control.
      
   2. When the Catalyst Differential Press value is 0.27 or more, it indicates a high possibility that DPF catalyst is clogged.
      

1. Connect the GTS to the DLC3.
   

2. Turn the engine switch on (IG) and turn the GTS on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
   

4. Read the DTCs.
   
   

   Result

   Result	Proceed to
   DTC P244A is output	A
   DTC P244B is output at the same time as P2463*	B
   DTC P0420, P2458 or P2463 is output	C
   Other relevant DTCs are output	D

   HINT:

   1. *: When P244B is output at the same time as P2463, perform troubleshooting for P244B.
      
   2. When DTC P1603, P1604 or P1608 is output in addition to P0420, perform troubleshooting for P1603, P1604 or P1608 first.
      

CAUTION:

Be careful of being burned by exhaust gases during the following inspection.

HINT:

Before checking the differential pressure sensor, perform a visual inspection of the differential pressure pipes and check that they are properly connected and no air is leaking from the pipes or hoses. If a malfunction is found, repair it before checking the sensor.

1. Disconnect the air hoses (both upstream and downstream) from the differential pressure sensor.
   

2. Start the engine.
   

3. Check if there are exhaust gas pulsations from both air hoses during idling.
   

   OK:

   Exhaust gas pulsation exists.
   

1. Repair or replace No. 1 vacuum pipe or No. 2 vacuum pipe.
   

1. Connect the GTS to the DLC3.
   

2. Turn the engine switch on (IG) and turn the GTS on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.
   

4. Check that the differential pressure is as specified below.
   
   

   Result

   Data List	Condition	Differential Pressure Output
   DPF Differential Pressure	Engine switch on (IG)	Approximately 0 kPa

1. Connect the upstream air hose to the differential pressure sensor.
   

2. Connect the GTS to the DLC3.
   

3. Turn the engine switch on (IG) and turn the GTS on.
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.
   

5. Start the engine.
   

6. Engine is running at 4000 rpm with no load for 10 seconds or more.
   

7. Check that the differential pressure is as specified below.
   
   

   Result

   DPF Differential Pressure	Proceed to
   1.5 kPa or higher	A
   below 1.5 kPa	B

   HINT:

   If the downstream differential pressure hose is disconnected, only the pressure of the upstream part of the differential pressure sensor changes. Therefore, the DPF differential pressure indicates the absolute value of the pressure before the DPF. If this occurs, as long as the characteristic of the differential pressure sensor is normal, the DPF differential pressure is equivalent to the back pressure (1.5 kPa or more).

1. Replace the differential pressure sensor (LandCruiser RM000005UKB000X.html).
   

1. Connect the downstream air hose to the differential pressure sensor.
   

   
   
   
   

2. Connect the GTS to the DLC3.
   

3. Turn the engine switch on (IG) and turn the GTS on.
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.
   

5. Start the engine.
   

6. Engine is running at 4000 rpm with no load for 10 seconds or more.
   

7. Check that the differential pressure is as specified below.
   
   

   Result

   DPF Differential Pressure	Proceed to
   -1.5 to 1.5 kPa	A
   Higher than 1.5 kPa	B

1. It has been determined that the exhaust manifold converter sub-assembly needs to be replaced. However, perform all the troubleshooting procedures before replacing the exhaust manifold converter sub-assembly.
   

   HINT:

   If the differential pressure before and after the DPF is low, it is very likely that there is no DPF or the material inside the DPF is missing due to erosion, etc. If the DPF catalyst is eroded, do not replace the DPF at this time, as troubleshooting the cause and other repairs are necessary.

1. Diagnose relevant DTCs (LandCruiser RM0000031HW07OX.html).
   

1. Start the engine and drive the vehicle until the engine coolant temperature reaches 75°C (167°F) or higher.
   

2. Stop the vehicle and allow the engine to idle.
   

3. Fully depress the accelerator pedal for 5 seconds, and then release it [A].
   

4. Repeat the above procedure [A] 10 times [B].
   

5. Check for black smoke emission during procedures [A] and [B].
   

   OK:

   Black smoke is emitted less than 5 times.
   

   HINT:

   Even if the black smoke is very thin, count the number of black smoke emissions if there is any visible smoke.

1. It has been determined that the exhaust manifold converter sub-assembly needs to be replaced. However, perform all the troubleshooting procedures before replacing the exhaust manifold converter sub-assembly.
   

   HINT:

   This DTC is stored because an excessive amount of PM has accumulated and resulted in abnormal combustion. It is necessary to diagnose the cause of abnormal PM accumulation and repair the problem. Therefore, do not perform replacement at this time.

1. Remove the EFI-MAIN NO.1 fuse or disconnect the cable from the battery terminal for 60 seconds or more, and then reinstall the EFI-MAIN NO.1 fuse or reconnect the cable to the battery terminal.
   

   HINT:

   1. The amount of built up particulate matter recorded by the ECM cannot be initialized by the GTS.
      
   2. If the amount of built up particulate matter recorded by the ECM is not initialized, PM forced regeneration cannot be performed using the GTS.
      

2. Turn the engine switch on (IG).
   

3. Turn the engine switch off and wait for 30 seconds or more.
   

4. Turn the engine switch on (IG) and wait for 10 seconds or more
   

5. Connect the GTS to the DLC3.
   

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

7. Maintain the maximum possible engine speed under no load for 10 seconds to blow out all soot from inside the exhaust pipe.
   

   HINT:

   1. If only a low engine speed is continuously maintained, soot may accumulate at the end of the catalyst.
      
   2. When soot accumulates at the end of the catalyst, it may not be possible to perform PM forced regeneration control normally.
      

8. Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the DPF Rejuvenate (PM) /Data List / Diesel Exhaust / Exhaust Temperature Sensor B1S2.
   

9. Perform the Active Test.
   

   CAUTION:

   Be careful of the exhaust pipes and surrounding areas, as they become extremely hot when performing PM forced regeneration.

   HINT:

   When PM Accumulation Ratio is too low, Activate the DPF Rejuvenate (PM) cannot be performed. Therefore, rev the engine with no load at 3400 rpm for 5 to 10 minutes to increase PM Accumulation Ratio to 12% or more.

10. Check for temperature increases and abnormal white smoke during PM forced regeneration.
    

    HINT:

    1. PM forced regeneration takes 15 to 40 minutes to finish.
       
    2. The time it takes to complete PM forced regeneration changes depending on "PM Accumulation Ratio" and the vehicle operating conditions.
       
    3. If the value of "Catalyst Differential Press" increases too much during the PM forced regeneration, the fail-safe function activates and PM forced regeneration is stopped.
       
    4. Perform PM forced regeneration control until the display on the multi-information display turns off.
       
    5. If actions such as depressing the accelerator pedal or clutch pedal, etc. are performed during PM forced regeneration, PM forced regeneration stops. If PM forced regeneration stops, it is necessary to perform it again.
       
    6. PM forced regeneration control is not complete until the display on the multi-information display turns off.
       
    
    

    Result

    Result	Proceed to
    During PM forced regeneration, temperature of Exhaust Temperature Sensor B1S2 is 300 to 500°C and no white smoke is generated	A
    During PM forced regeneration, temperature of Exhaust Temperature Sensor B1S2 is 300 to 500°C and abnormal white smoke is generated*1	B
    Other than above*2	C

    HINT:

    1. *1: If abnormal white smoke is only generated during PM forced regeneration, there may be uncombusted fuel due to deterioration of the DPF catalyst.
       
    2. *1: When there is a malfunction with combustion control, operation performance may be reduced and abnormalities may be felt even if PM forced regeneration is performed.
       
    3. *2: An excess of accumulated PM is the result of a malfunction in the control system causing poor combustion and an increase in black smoke.
       

1. It has been determined that the exhaust fuel addition injector assembly needs to be replaced. However, perform all the troubleshooting procedures before replacing the exhaust fuel addition injector assembly.
   

1. It has been determined that the exhaust manifold converter sub-assembly needs to be replaced. However, perform all the troubleshooting procedures before replacing the exhaust manifold converter sub-assembly.
   

   HINT:

   If abnormal white smoke is only generated during PM forced regeneration, there may be uncombusted fuel due to deterioration of the DPF catalyst. When there is a malfunction with combustion control, operation performance may be reduced and abnormalities may be felt even if PM forced regeneration is performed.

1. Check the fuel injection system (LandCruiser RM000004KNK022X.html).
   

1. Check the intake/exhaust system (LandCruiser RM000004KNL01SX.html).
   

1. Check the after treatment control system (LandCruiser RM000004KNM01IX.html).
   

HINT:

Replace the following items only when it has been determined necessary based on diagnosis for DTC P0420, P244A, P2458 and P2463.

1. Replace the exhaust fuel addition injector assembly (LandCruiser RM000005UK8000X.html).
   

2. Replace the exhaust manifold converter sub-assembly (LandCruiser RM000005UKF000X.html).
   

   NOTICE:

   Perform Initialization procedure for "DPF catalyst record clear" and "DPF Deterioration Record Clear" (LandCruiser RM000000TIN08HX.html).

3. Repair or replace the malfunctioning part confirmed in the diagnosis of the fuel injection system, intake/exhaust system and after treatment control system.
   

4. Check for DTCs output in step 1.
   
   

   Result:

   
   

   Result	Proceed to
   DTC P244A is output	A
   DTC other than P244A output	B

1. Connect the GTS to the DLC3.
   

2. Turn the engine switch on (IG) and turn the GTS on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Data List / DPF Differential Pressure.
   

4. Start the engine.
   

5. Engine is running at 4000 rpm with no load for 10 seconds or more.
   

6. Confirmation that the differential pressure is higher than 1.5 kPa.
   

1. Connect the GTS to the DLC3.
   

2. Turn the engine switch on (IG) and turn the GTS on.
   

3. Clear the DTCs (LandCruiser RM000000PDK1E5X.html).
   

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

5. Perform PM forced regeneration (LandCruiser RM000005UDV000X_01_0001.html).