Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM10000000255V1
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [09/2022 -           ]
Title: G16E-GTS (ENGINE CONTROL): SFI SYSTEM: P042000; Catalyst System Efficiency Below Threshold Bank 1; 2023 - 2025 MY GR Corolla [09/2022 -        ]

DTC

P042000

Catalyst System Efficiency Below Threshold Bank 1

MONITOR DESCRIPTION

The ECM uses air fuel ratio sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency.

The first sensor, the air fuel ratio sensor (sensor 1), sends pre-catalyst information to the ECM. The second sensor, the air fuel ratio sensor (sensor 2), sends post-catalyst information to the ECM.

In order to detect any deterioration in the three-way catalytic converter, the ECM calculates the oxygen storage capacity of the three-way catalytic converter. This calculation is based on the output current of the air fuel ratio sensor (sensor 2) while performing active air fuel ratio control.

The oxygen storage capacity value is an indication of the oxygen storage capacity of the three-way catalytic converter. When the vehicle is being driven with a warm engine, active air fuel ratio control is performed for approximately 30 seconds. When it is performed, the ECM deliberately sets the air fuel ratio to lean or rich levels. If the cycle of the waveform for the air fuel ratio sensor (sensor 2) is long, the oxygen storage capacity is great. There is a direct correlation between the air fuel ratio sensor (sensor 2) and the oxygen storage capacity of the three-way catalytic converter.

The ECM uses the oxygen storage capacity value to determine the state of the three-way catalytic converter. If any deterioration has occurred, the ECM will illuminate the MIL and store a DTC.

This system determines the deterioration of the entire catalyst system (including the front and rear catalysts), by using the oxygen storage capacity value of the front catalyst, that is more sensitive than the rear catalyst, as the representative value. Therefore, be sure to replace the front and rear catalysts together when catalyst replacement is necessary.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Note

P042000

Catalyst System Efficiency Below Threshold Bank 1

The oxygen storage capacity value is less than the standard value under active air fuel ratio control (1 trip detection logic).

  • Gas leak from exhaust system
  • Air fuel ratio sensor (sensor 1)
  • Air fuel ratio sensor (sensor 2)
  • Exhaust manifold (TWC: Front catalyst)
  • Front exhaust pipe assembly (TWC: Rear catalyst)

Comes on

SAE Code: P0420

CATALYST LOCATION

*1

Exhaust Manifold (TWC: Front Catalyst)

*2

Front Exhaust Pipe Assembly (TWC: Rear Catalyst)

*3

Tail Exhaust Pipe Assembly

*4

Air Fuel Ratio Sensor (Sensor 1)

*5

Air Fuel Ratio Sensor (Sensor 2)

-

-

NOTICE:

When replacing the exhaust manifold (*1) and the front exhaust pipe assembly (*2) in order to replace the three-way catalytic converter, it is not necessary to replace the air fuel ratio sensor (sensor 1) (*4) and the air fuel ratio sensor (sensor 2) (*5).

MONITOR STRATEGY

Related DTCs

P0420: Catalyst deterioration

Required Sensors/Components (Main)

Air fuel ratio sensor (sensor 1)

Air fuel ratio sensor (sensor 2)

Required Sensors/Components (Related)

Intake air temperature sensor

Mass air flow meter sub-assembly

Crankshaft position sensor

Engine coolant temperature sensor

Frequency of Operation

Once per driving cycle

Duration

Approximately 30 seconds

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

P0010 (VVT oil control solenoid)

P0011 (VVT system - advance)

P0012 (VVT system - retard)

P0013 (Exhaust VVT oil control solenoid)

P0014 (Exhaust VVT system - advance)

P0015 (Exhaust VVT system - retard)

P0016 (VVT system - misalignment)

P0017 (Exhaust VVT system - misalignment)

P0031, P0032, P101D (Air fuel ratio sensor (sensor 1) heater)

P0037, P0038, P102D (Air fuel ratio sensor (sensor 2) heater)

P005D, P014C, P014D, P015A, P015B, P2195, P2196, P2237, P2238, P2239, P2252, P2253 (Air fuel ratio sensor (sensor 1))

P0087, P0088, P0191, P0192, P0193 (Fuel pressure sensor (for high pressure side))

P00CF, P0237, P0238 (Turbocharger)

P0101, P0102, P0103 (Mass air flow meter)

P0106, P0107, P0108 (Manifold absolute pressure)

P0111, P0112, P0113 (Intake air temperature sensor)

P0116, P0117, P0118 (Engine coolant temperature sensor)

P0121, P0122, P0123, P0222, P0223, P2135 (Throttle position sensor)

P0125 (Insufficient coolant temperature for closed loop fuel control)

P0128 (Thermostat)

P0136, P013A, P2270, P2271, P22AB, P22AC, P22AD, P22B3, P22B4 (Air fuel ratio sensor (sensor 2))

P0171, P0172 (Fuel system)

P0201, P0202, P0203, P062D, P21CF, P21D0, P21D1 (Fuel injector)

P0300 - P0303 (Misfire)

P0327, P0328 (Knock control sensor)

P0335, P0337, P0338 (Crankshaft position sensor)

P0340, P0342, P0343 (Camshaft position sensor)

P0365, P0367, P0368 (Exhaust camshaft position sensor)

P0500 (Vehicle speed sensor)

P0657, P0658, P2102, P2103, P2111, P2112, P2119 (Throttle actuator)

P107B, P107C, P107D (Fuel pressure sensor (for low pressure side))

P11EA, P11EC, P11ED, P11EE, P219A, P219C, P219D, P219E (Air-fuel ratio imbalance)

P1235 (High pressure fuel pump circuit)

P2228, P2229 (Atmospheric pressure sensor)

Response rate during fuel cut from rich condition

Completed

Battery voltage

11 V or higher

Intake air temperature

-10°C (14°F) or higher

Engine coolant temperature

75°C (167°F) or higher

Atmospheric pressure

76 kPa(abs) [11 psi(abs)] or higher

Idling

Off

Engine speed

Less than 4000 rpm

Sub feedback control

Executing

Air fuel ratio sensor (sensor 1) status

Activated

Fuel system status

Closed loop

Engine load

10% or higher, and less than 160%

All of the following conditions are met

1, 2 and 3

1. Mass air flow

2.9 gm/sec or more, and less than 60 gm/sec

2. Front catalyst temperature (estimated)

500°C (932°F) or higher, and below 820°C (1508°F)

3. Rear catalyst temperature (estimated)

270°C (518°F) or higher, and below 700°C (1292°F)

Shift position

3rd or higher

TYPICAL MALFUNCTION THRESHOLDS

Oxygen Storage Capacity (OSC) of catalyst (Normalized)

Less than 1

MONITOR RESULT

Refer to detailed information in Checking Monitor Status.

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: CHECKING MONITOR STATUS

P0420: Catalyst Efficiency / O2 STORAGE B1

Monitor ID

Test ID

Scaling

Unit

Description

$21

$AF

Multiply by 0.001

No dimension

Oxygen storage capacity of catalyst bank 1 (Normalization)

CONFIRMATION DRIVING PATTERN

HINT:

  • It is necessary for the response of the air fuel ratio sensor (sensor 2) to be normal in order to confirm DTC P042000. Therefore, perform the confirmation driving pattern for the air fuel ratio sensor (sensor 2) monitor before performing the confirmation driving pattern for the catalyst efficiency monitor.
  • Performing this confirmation driving pattern will activate the catalyst efficiency monitor. This is very useful for verifying the completion of a repair.
  • After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

    Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

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

    Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR

  1. Connect the GTS to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the GTS on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the ignition switch off and wait for at least 30 seconds.
  6. Turn the ignition switch to ON.
  7. Turn the GTS on.
  8. Enter the following menus: Powertrain / Engine / Monitor / Current Monitor.
  9. Check that Catalyst Efficiency / Current is Incomplete.
  10. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with the shift lever in P [A].

    HINT:

    In order to keep the idle stable, turn the A/C and all other electric loads off and do not perform any shift operations.

  11. Drive the vehicle at approximately 60 km/h (37 mph) for 10 minutes or more [B].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    HINT:

    Drive the vehicle while keeping the engine load as constant as possible.

  12. With the shift lever in S, drive the vehicle at 60 km/h (37 mph), and then decelerate the vehicle by releasing the accelerator pedal for 5 seconds or more to perform the fuel-cut [C].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  13. Enter the following menus: Powertrain / Engine / Monitor / Current Monitor / O2 Sensor / Details / SLOW RESPONSE B1S2 [D].
  14. Check the Test Value for SLOW RESPONSE B1S2.

    HINT:

    • If Test Value displays a value larger than 0, perform the following procedure, as the O2 Sensor monitor is finished.
    • If Test Value displays 0, perform step [C] until it displays a value larger than 0, as the O2 Sensor monitor is not finished.
  15. Turn the ignition switch off and wait for at least 30 seconds [F].
  16. Turn the ignition switch to ON.
  17. Turn the GTS on.
  18. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [G].
  19. Drive the vehicle at approximately 60 km/h (37 mph) for 10 minutes or more [H].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    HINT:

    • Drive the vehicle while keeping the engine load as constant as possible.
    • The monitor item will change to Complete as the Catalyst Efficiency monitor operates.
  20. Enter the following menus: Powertrain / Engine / Trouble Codes [I].
  21. Check if any DTCs are stored.

    HINT:

    • If the monitor item does not change to Complete, and no DTCs are stored, perform the following procedure.
    • [A] to [I]: Normal judgment procedure.

      The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

    • When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.
  22. Drive the vehicle at a speed between 75 and 100 km/h (47 and 62 mph) for 10 minutes or more [J].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

    HINT:

    • Drive the vehicle while keeping the engine load as constant as possible.
    • The monitor item will change to Complete as the Catalyst Efficiency monitor operates.
  23. Enter the following menus: Powertrain / Engine / Trouble Codes [K].
  24. Check if any DTCs are stored.

    HINT:

    If the monitor item does not change to Complete, and no DTCs are stored, extend the driving time.

  25. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
  26. Input the DTC: P042000.
  27. Check the DTC judgment result.

    GTS Display

    Description

    NORMAL

    • DTC judgment completed
    • System normal

    ABNORMAL

    • DTC judgment completed
    • System abnormal

    INCOMPLETE

    • DTC judgment not completed
    • Perform driving pattern after confirming DTC enabling conditions

    HINT:

    • If the judgment result is NORMAL, the system is normal.
    • If the judgment result is ABNORMAL, the system has a malfunction.
    • [A] to [K]: Normal judgment procedure.

      The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

    • When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

CAUTION / NOTICE / HINT

HINT:

  • If a malfunction cannot be found when troubleshooting DTC P042000, a lean or rich abnormality may be the cause. Perform troubleshooting by following the inspection procedure for P017100 (System Too Lean) and P017200 (System Too Rich).
  • Sensor 1 refers to the sensor closest to the engine assembly.
  • Sensor 2 refers to the sensor farthest away from the engine assembly.
  • Read Freeze Frame Data using the GTS. 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

1.

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P042000)

(a) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Proceed to

P042000 and other DTCs are output

A

P042000 is output

B

HINT:

If any DTCs other than P042000 are output, troubleshoot those DTCs first.

A

GO TO DTC CHART

B

2.

PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

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

(b) Warm up the air fuel ratio sensors at an engine speed of 2500 rpm for 90 seconds.

(c) Enter the following menus.

Powertrain > Engine > Active Test

Active Test Display

Control the Injection Volume for A/F Sensor

Data List Display

Coolant Temperature

Injection Volume

A/F (O2) Sensor Current B1S1

A/F (O2) Sensor Current B1S2

HINT:

  • The Active Test "Control the Injection Volume for A/F Sensor" can be used to lower the fuel injection volume by 12.5% or increase the injection volume by 12.5%.
  • The air fuel ratio sensor (sensor 1) is displayed as A/F (O2) Sensor Current B1S1, and the air fuel ratio sensor (sensor 2) is displayed as A/F (O2) Sensor Current B1S2 on the GTS.
  • The air fuel ratio sensor (sensor 1) has an output delay of a few seconds and the air fuel ratio sensor (sensor 2) has a maximum output delay of approximately 20 seconds.
  • If the sensor output current does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

Standard:

GTS Display

(Sensor)

Injection Volume

Status

Current

A/F (O2) Sensor Current B1S1

(Air fuel ratio (sensor 1))

12.5%

Rich

Below -0.075 mA

-12.5%

Lean

Higher than 0.037 mA

A/F (O2) Sensor Current B1S2

(Air fuel ratio (sensor 2))

12.5%

Rich

Below -0.86 mA

-12.5%

Lean

Higher than 0.33 mA

Status A/F (O2) Sensor Current B1S1

Status A/F (O2) Sensor Current B1S2

Actual air fuel ratio, air fuel ratio sensor (sensor 1) and air fuel ratio sensor (sensor 2) condition

Main Suspected Trouble Area

Proceed to

Lean/Rich

Lean/Rich

Normal

  • Three-way catalytic converter
  • Gas leak from exhaust system

A

Lean

Lean/Rich

Air fuel ratio sensor (sensor 1) malfunction

  • Air fuel ratio sensor (sensor 1)

B

Rich

Lean/Rich

Air fuel ratio sensor (sensor 1) malfunction

  • Air fuel ratio sensor (sensor 1)

B

Lean/Rich

Lean

Air fuel ratio sensor (sensor 2) malfunction

  • Air fuel ratio sensor (sensor 2)
  • Gas leak from exhaust system

C

Lean/Rich

Rich

Air fuel ratio sensor (sensor 2) malfunction

  • Air fuel ratio sensor (sensor 2)
  • Gas leak from exhaust system

C

Lean

Lean

Actual air fuel ratio lean

  • Extremely lean actual air fuel ratio
  • Gas leak from exhaust system

D

Rich

Rich

Actual air fuel ratio rich

  • Extremely rich actual air fuel ratio
  • Gas leak from exhaust system

D

  • Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently higher than 0.037 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently higher than 0.33 mA.
  • Rich: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently below -0.075 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently below -0.86 mA.
  • Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output current of the air fuel ratio sensor (sensor 1) or air fuel ratio sensor (sensor 2) alternate correctly.

HINT:

Refer to "Data List / Active Test" [A/F (O2) Sensor Current B1S1, A/F (O2) Sensor Current B1S2].

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: DATA LIST / ACTIVE TEST

B

GO TO STEP 4

C

GO TO STEP 5

D

GO TO STEP 7

A

3.

CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks in exhaust system.

OK

GO TO STEP 28

NG

GO TO STEP 25

4.

REPLACE AIR FUEL RATIO SENSOR (SENSOR 1)

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HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NEXT

GO TO STEP 26

5.

CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks in exhaust system.

NG

GO TO STEP 25

OK

6.

REPLACE AIR FUEL RATIO SENSOR (SENSOR 2)

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HINT:

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 2).

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NEXT

GO TO STEP 26

7.

CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks in exhaust system.

NG

GO TO STEP 25

OK

8.

CHECK PCV VALVE AND HOSE CONNECTIONS

(a) Check the PCV hose connections.

(b) Check the PCV valve.

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (EMISSION CONTROL): PCV VALVE: INSPECTION

OK:

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

NG

REPAIR OR REPLACE PCV VALVE OR HOSE

OK

9.

CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks.

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (INTAKE / EXHAUST): INTAKE SYSTEM: ON-VEHICLE INSPECTION

OK:

No leaks in intake system.

HINT:

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

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NG

REPAIR OR REPLACE INTAKE SYSTEM

OK

10.

READ VALUE USING GTS (COOLANT TEMPERATURE)

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

Powertrain > Engine > Data List

Tester Display

Coolant Temperature

Standard:

GTS Display

Condition

Specified Condition

Coolant Temperature

Cold engine

Same as ambient air temperature

Warm engine

Between 75 and 100°C (167 and 212°F)

HINT:

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

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NG

REPLACE ENGINE COOLANT TEMPERATURE SENSOR

OK

11.

INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): MASS AIR FLOW METER: INSPECTION

NG

GO TO STEP 17

OK

12.

CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE)

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (FUEL): FUEL SYSTEM: ON-VEHICLE INSPECTION+

NG

GO TO STEP 24

OK

13.

CHECK FUEL PRESSURE (FOR HIGH PRESSURE SIDE)

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (FUEL): FUEL SYSTEM: ON-VEHICLE INSPECTION+

NG

GO TO STEP 24

OK

14.

INSPECT IGNITION SYSTEM

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): IGNITION SYSTEM: ON-VEHICLE INSPECTION

HINT:

  • If the spark plugs or ignition system malfunctions, engine misfire may occur. The misfire count can be read using the GTS. Enter the following menus: Powertrain / Engine / Data List / Misfire Count Cylinder #1 to Misfire Count Cylinder #3.
  • Perform "Inspection After Repair" after repairing or replacing the ignition system.

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NG

REPAIR OR REPLACE IGNITION SYSTEM

OK

15.

INSPECT PORT FUEL INJECTOR ASSEMBLY

(a) Inspect the port fuel injector assembly (whether fuel volume is high or low, and whether injection pattern is poor).

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (FUEL): FUEL INJECTOR (for Port Injection): INSPECTION

HINT:

Perform "Inspection After Repair" after replacing the port fuel injector assembly.

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NG

REPLACE PORT FUEL INJECTOR ASSEMBLY 2023 MY GR Corolla [09/2022 - 11/2022]; G16E-GTS (FUEL): FUEL INJECTOR (for Port Injection): REMOVAL 2023 - 2025 MY GR Corolla [11/2022 -        ]; G16E-GTS (FUEL): FUEL INJECTOR (for Port Injection): REMOVAL

OK

16.

INSPECT DIRECT FUEL INJECTOR ASSEMBLY

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (FUEL): FUEL INJECTOR (for Direct Injection): INSPECTION

HINT:

Perform "Inspection After Repair" after replacing the direct fuel injector assembly.

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NG

REPLACE DIRECT FUEL INJECTOR ASSEMBLY 2023 MY GR Corolla [09/2022 - 11/2022]; G16E-GTS (FUEL): FUEL INJECTOR (for Direct Injection): REMOVAL 2023 - 2025 MY GR Corolla [11/2022 -        ]; G16E-GTS (FUEL): FUEL INJECTOR (for Direct Injection): REMOVAL

OK

17.

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY CONNECTOR CONNECTION)

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

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HINT:

Repair any problems.

NEXT

18.

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Engine > Clear DTCs

(b) Turn the ignition switch off and wait for at least 30 seconds.

NEXT

19.

CHECK WHETHER DTC OUTPUT RECURS (DTC P042000)

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

(b) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are not output

A

P042000 is output

B

A

END

B

20.

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

(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:

Tester Connection

Condition

Specified Condition

C26-3(VCC) - C142-84(VCVG)

Always

Below 1 Ω

C26-1(FG) - C142-107(VG)

Always

Below 1 Ω

C26-2(E2G) - C142-83(E2G)

Always

Below 1 Ω

C26-3(VCC) or C142-84(VCVG) - Body ground and other terminals

Always

10 kΩ or higher

C26-1(FG) or C142-107(VG) - Body ground and other terminals

Always

10 kΩ or higher

C26-2(E2G) or C142-83(E2G) - Body ground and other terminals

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

21.

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): MASS AIR FLOW METER: REMOVAL

HINT:

  • If the result of the inspection performed in steps 11 (INSPECT MASS AIR FLOW METER SUB-ASSEMBLY) 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.

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NEXT

22.

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Engine > Clear DTCs

(b) Turn the ignition switch off and wait for at least 30 seconds.

NEXT

23.

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

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

(b) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are not output

A

P042000 is output

B

A

END

B

REPLACE ECM 2023 MY GR Corolla [09/2022 - 11/2022]; G16E-GTS (ENGINE CONTROL): ECM: REMOVAL 2023 - 2025 MY GR Corolla [11/2022 -        ]; G16E-GTS (ENGINE CONTROL): ECM: REMOVAL

24.

CHECK FUEL LINE

(a) Check the fuel lines for leaks or blockage.

OK

GO TO FUEL PUMP CONTROL CIRCUIT

NG

REPAIR OR REPLACE FUEL SYSTEM

25.

REPAIR OR REPLACE EXHAUST SYSTEM

HINT:

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

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (ENGINE CONTROL): SFI SYSTEM: INITIALIZATION

NEXT

26.

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Engine > Clear DTCs

(b) Turn the ignition switch off and wait for at least 30 seconds.

NEXT

27.

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

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

(b) Read the DTCs.

Powertrain > Engine > Trouble Codes

Result

Proceed to

DTCs are not output

A

P042000 is output

B

A

END

B

28.

REPLACE EXHAUST MANIFOLD (TWC: FRONT CATALYST) AND FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST)

NOTICE:

When replacing the exhaust manifold and the front exhaust pipe assembly in order to replace the three-way catalytic converter, it is not necessary to replace the air fuel ratio sensor (sensor 1) and the air fuel ratio sensor (sensor 2).

HINT:

Confirm the replacement parts, referring to the illustration in the Catalyst Location.

(a) Replace the exhaust manifold (TWC: Front catalyst).

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (INTAKE / EXHAUST): TURBOCHARGER: REMOVAL

(b) Replace the front exhaust pipe assembly (TWC: Rear catalyst).

Click here 2023 - 2025 MY GR Corolla [09/2022 -        ]; G16E-GTS (INTAKE / EXHAUST): EXHAUST PIPE: REMOVAL

NEXT

END