Dtc P0420 Catalyst System Efficiency Below Threshold (Bank 1). Corolla Auris

Двигатель. COROLLA, AURIS. ZZE150 ZRE151,152 NDE150
Система Управления Двигателем 2Zr-Fe. COROLLA, AURIS. ZZE150 ZRE151,152 NDE150

DESCRIPTION

CONFIRMATION DRIVING PATTERN

CONDITIONING FOR SENSOR TESTING

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0420)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME CONTROL)

INSPECT FOR EXHAUST GAS LEAK

INSPECT FOR EXHAUST GAS LEAK

DTC P0420 Catalyst System Efficiency Below Threshold (Bank 1)


DESCRIPTION

The ECM uses sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency.
The first sensor, the Air Fuel Ratio (A/F) sensor, sends pre-catalyst information to the ECM. The second sensor, the Heated Oxygen (HO2) sensor, sends post-catalyst information to the ECM.
In order to detect any deterioration in the TWC, the ECM calculates the Oxygen Storage Capacity (OSC) of the TWC. This calculation is based on the voltage output of the HO2 sensor while performing active air fuel ratio control, rather than the conventional detecting method, which uses the locus ratio.
The OSC value is an indication of the oxygen storage capacity of the TWC. When the vehicle is being driven with a warm engine, active air fuel ratio control is performed for approximately 15 to 20 seconds. When it is performed, the ECM deliberately sets the air fuel ratio to lean or rich levels. If the rich-lean cycle of the HO2 sensor is long, the OSC becomes greater. There is a direct correlation between the OSCs of the HO2 sensor and the TWC.
The ECM uses the OSC value to determine the state of the TWC. If any deterioration has occurred, it illuminates the MIL and sets the DTC.

DTC No.
DTC Detection Condition
Trouble Area
P0420
Oxygen Storage Capacity (OSC) value smaller than standard value under active air fuel ratio control
(2 trip detection logic)
  1. Front exhaust pipe (with three-way catalytic converter)
  2. Gas leak from exhaust system
  3. Air fuel ratio sensor (sensor 1)
  4. Heated oxygen sensor (sensor 2)

CONFIRMATION DRIVING PATTERN

УКАЗАНИЕ:
Performing this confirmation pattern will activate the catalyst monitor. This is very useful for verifying the completion of a repair.

COROLLA, AURIS. ZZE150 ZRE151,152 NDE150.Система Управления Двигателем 2Zr-Fe.Система Sfi. Dtc P0420 Catalyst System Efficiency Below Threshold (Bank 1)

  1. (a) Connect the intelligent tester to the DLC3.
  2. (b) Turn the ignition switch on (IG).
  3. (c) Turn the tester on, and select the following menu items: Powertrain / Engine and ECT / DTC / Clear.
  4. (d) Clear DTCs (if set).
  5. (f) Select the following menu items: Powertrain / Engine and ECT / Data List / Catalyst Monitor.
  6. (g) Check that Catalyst Monitor is INCMPL (incomplete).
  7. (h) Start the engine and warm it up.
  8. (i) Drive the vehicle at between 90 km/h and 110 km/h (56 mph and 68 mph) for at least 10 minutes.
  9. (j) Those items will change to COMPL (Complete) as Catalyst Monitor operates.
  10. (k) On the tester, select the following menu items: Powertrain / Engine / DTC / Pending; then check if any DTCs (any pending DTCs) are set.
УКАЗАНИЕ:
If Catalyst Monitor does not change to COMPL (Complete), and any pending DTCs fail to set, extend the driving time.

CONDITIONING FOR SENSOR TESTING

УКАЗАНИЕ:
Perform the operation with the engine speeds and time durations described below prior to checking the waveforms of the Air Fuel Ratio (A/F) and Heated Oxygen (HO2) sensors. This is in order to activate the sensors sufficiently to obtain the appropriate inspection results.

COROLLA, AURIS. ZZE150 ZRE151,152 NDE150.Система Управления Двигателем 2Zr-Fe.Система Sfi. Dtc P0420 Catalyst System Efficiency Below Threshold (Bank 1)

  1. (a) Connect an intelligent tester to the DLC3.
  2. (b) Start the engine and warm it up with all the accessories switched OFF, until the engine coolant temperature stabilizes.
  3. (c) Run the engine at an engine speed of between 2,500 rpm and 3,000 rpm for at least 3 minutes.
  4. (d) While running the engine at 3,000 rpm and 2,000 rpm alternating at 2 second intervals, check the waveforms of the A/F and HO2 sensors using the tester.
УКАЗАНИЕ:
  1. If either voltage output of the A/F or HO2 sensor does not fluctuate, or there is a noise in the waveform of either sensor may be malfunctioning.
  2. If the voltage outputs of both the sensors remain lean or rich, the air-fuel ratio may be extremely lean or rich. In such cases, perform the following menu items: Powertrain / Engine / Active Test / Control the Injection Volume for A/F sensor.
  3. If the Three-Way Catalytic Converter (TWC) has deteriorated, the HO2 sensor (located behind the TWC) voltage output fluctuates up and down frequently, even under normal driving conditions (active air-fuel ratio control is not performed).

COROLLA, AURIS. ZZE150 ZRE151,152 NDE150.Система Управления Двигателем 2Zr-Fe.Система Sfi. Dtc P0420 Catalyst System Efficiency Below Threshold (Bank 1)


INSPECTION PROCEDURE

УКАЗАНИЕ:
Read freeze frame data using an intelligent tester. Freeze frame data record 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, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.
1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0420)

  1. Connect an intelligent tester to the DLC3.

  1. Turn the ignition switch on (IG) and turn the tester on.

  1. Select the following menu items: Powertrain / Engine and ECT / DTC.

  1. Read DTCs.

    Result:
    Result
    		Proceed to
    P0420
    		A
    P0420 and other DTCs
    		B
    УКАЗАНИЕ:
    If any DTCs other than P0420 are output, troubleshoot those DTCs first.


B
GO TO DTC CHART (Нажмите здесь)
A


2.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (INJECTION VOLUME CONTROL)

  1. Connect the intelligent tester to the DLC3.

  1. Start the engine and turn the tester on.

  1. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.

  1. Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F sensor.

  1. Perform the Control the Injection Volume for A/F sensor operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).

  1. Monitor the voltage outputs of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2) displayed on the tester.

    УКАЗАНИЕ:
    1. The Control the Injection Volume for A/F sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
    2. Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

      Standard:

      Tester Display
      (Sensor)
      		Injection Volume
      		Status
      		Voltage
      AFS B1 S1
      (A/F)
      		+25%
      		Rich
      		Less than 3.0 V
      AFS B1 S1
      (A/F)
      		-12.5%
      		Lean
      		More than 3.35 V
      O2S B1 S2
      (HO2)
      		+25%
      		Rich
      		More than 0.55 V
      O2S B1 S2
      (HO2)
      		-12.5%
      		Lean
      		Less than 0.4 V

      Result:

      Status
      AFS B1 S1
      		Status
      O2S B1 S2
      		A/F Condition and A/F and
      HO2 Sensors Conditions
      		Misfires
      		Main Suspected Trouble Area
      		Proceed to
      Lean/Rich
      		Lean/Rich
      		Normal
      		-
      1. Three-Way Catalytic Converter (TWC)
      2. Gas leak from exhaust system
      		A
      Lean
      		Lean/Rich
      		A/F sensor malfunction
      		-
      1. A/F sensor
      		B
      Rich
      		Lean/Rich
      		A/F sensor malfunction
      		-
      1. A/F sensor
      Lean/Rich
      		Lean
      		HO2 sensor malfunction
      		-
      1. HO2 sensor
      2. Gas leak from exhaust system
      		C
      Lean/Rich
      		Rich
      		HO2 sensor malfunction
      		-
      1. HO2 sensor
      2. Gas leak from exhaust system
      Lean
      		Lean
      		Actual air-fuel ratio lean
      		May occur
      1. Extremely rich or lean actual air fuel ratio
      2. Gas leak from exhaust system
      		D
      Rich
      		Rich
      		Actual air-fuel ratio rich
      		-
      1. Extremely rich or lean actual air fuel ratio
      2. Gas leak from exhaust system
      Lean: During Control the Injection Volume for A/F sensor, the air fuel ratio sensor output voltage (AFS) is consistently more than 3.35 V, and the heated oxygen sensor output voltage (O2S) is consistently less than 0.4 V.
      Rich: During Control the Injection Volume for A/F sensor, the AFS is consistently less than 3.0 V, and the O2S is consistently more than 0.55 V.
      Lean/Rich: During Control the Injection Volume for A/F sensor of the Active Test, the output voltage of the air fuel ratio sensor and heated oxygen sensor alternates correctly.


B
REPLACE AIR FUEL RATIO SENSOR (Нажмите здесь)

C
Перейдите к шагу 4

D
CHECK AND REPLACE EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO, AND GO TO STEP 3 (Нажмите здесь)
A


3.INSPECT FOR EXHAUST GAS LEAK

  1. Inspect for exhaust gas leakage (See page Нажмите здесь).

    OK:
    No gas leak.


NG
REPAIR OR REPLACE EXHAUST GAS LEAK POINT
OK

REPLACE FRONT EXHAUST PIPE ASSEMBLY (THREE-WAY CATALYTIC CONVERTER)

4.INSPECT FOR EXHAUST GAS LEAK

  1. Inspect for exhaust gas leakage (See page Нажмите здесь).

    OK:
    No gas leak.


NG
REPAIR OR REPLACE EXHAUST GAS LEAK POINT
OK

REPLACE HEATED OXYGEN SENSOR (Нажмите здесь)