Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM100000002B352
Model Year Start: 2023 Model: Corolla Hatchback Prod Date Range: [03/2023 -           ]
Title: K120 / K121 (CVT): K121 CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: INITIALIZATION; 2023 - 2025 MY Corolla Corolla Hatchback [03/2023 -        ]

INITIALIZATION

NOTICE:

  • If Continuously Variable Transaxle (CVT) parts are replaced, perform the following as necessary:

    Parts Replacement Compensation Table

    Replaced Part

    Transaxle Compensation Code

    Reset Memory (Learned Values)

    CVT Oil Pressure Calibration

    Road Test

    Continuously variable transaxle assembly

    Input

    Reset

    Initialize

    Necessary

    Transmission valve body assembly

    Initialize

    Reset

    Initialize

    Necessary

    Oil pressure sensor

    -

    Reset

    Initialize

    Necessary

    ECM

    (If possible, read the transaxle compensation code from the previous ECM)

    Possible to read transaxle compensation code

    Input (Into new ECM)

    -

    Initialize

    Necessary

    Impossible to read transaxle compensation code

    Initialize

    -

    Initialize

    Necessary
  • Reset Memory cannot be completed by only disconnecting and reconnecting the cable to the negative (-) battery terminal.
  • After performing Reset Memory, perform CVT Oil Pressure Calibration.

RESET TRANSAXLE COMPENSATION CODE

NOTICE:

Do not start the engine.

(a) Move the shift lever to P and apply the parking brake.

(b) Enter the following menus: Powertrain / Engine / Utility / A/T Code Reset.

Powertrain > Engine > Utility

Tester Display

A/T Code Reset

(c) Select "Next" again to proceed.

NOTICE:

After the transaxle compensation code is initialized, perform Reset Memory and Perform Road Test to Allow ECM to Learn.

(d) Select "Exit".

PERFORM RESET MEMORY

NOTICE:

Do not start the engine.

(a) Move the shift lever to P and apply the parking brake.

(b) Enter the following menus: Powertrain / Engine / Utility / Reset Memory.

Powertrain > Engine > Utility

Tester Display

Reset Memory

NOTICE:

  • Make sure that the shift lever is in P.
  • Make sure that the engine is stopped. To prevent vibrations, do not start the engine.
  • Make sure that the ignition switch is ON.

PERFORM CVT OIL PRESSURE CALIBRATION

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

(b) Turn the ignition switch to ON and wait at least 2 seconds.

NOTICE:

Do not start the engine.

HINT:

Zero point calibration of the oil pressure sensor is performed when the ignition switch is turned to ON (engine stopped). However, zero point calibration will not be performed when any of the following conditions are met:

  • Oil pressure sensor value is 0.065 MPa (0.663 kgf/cm2, 9.43 psi) or more.
  • CVT oil temperature is 0°C (32°F) or less or 120°C (248°F) or more.

(c) Start the engine and wait at least 5 seconds.

(d) Enter the following menus: Powertrain / Engine / Utility / CVT Oil Pressure Calibration.

Powertrain > Engine > Utility

Tester Display

CVT Oil Pressure Calibration

HINT:

  • During CVT Oil Pressure Calibration, the engine idle speed will increase.
  • When "Complete" is displayed on the screen, CVT Oil Pressure Calibration is complete.
  • The learned values cannot be cleared by only disconnecting and reconnecting the cable to the negative (-) battery terminal.

PERFORM ROAD TEST TO ALLOW ECM TO LEARN

CAUTION:

  • Perform the following procedures while strictly observing all traffic laws and speed limits.
  • Do not accelerate or decelerate rapidly.

(a) Warm up the engine.

(b) With the shift lever in D, after gradually accelerating to 50 km/h (31 mph) or more, gradually decelerate until the vehicle stops.

NOTICE:

After accelerating, deceleration does not need to be performed immediately.

(c) Repeat the road test until the shift shock and engine speed overrun (engine speed flare when shifting) reach an acceptable level.

NOTICE:

When repeating the acceleration/deceleration cycle of a road test pattern, bring the vehicle to a complete stop before accelerating again.

PERFORM ATF THERMAL DEGRADATION ESTIMATE RESET

NOTICE:

If either of the following conditions is met, perform ATF Thermal Degradation Estimate Reset:

  • The CVT fluid has been replaced.

    HINT:

    If 50000 or more is displayed for the Data List item "ATF Thermal Degradation Estimate", thermal degradation of the CVT fluid is suspected. Perform ATF Thermal Degradation Estimate Reset after replacing the CVT fluid.

  • Approximately 50% or more of the CVT fluid has been replaced during a repair of the transaxle or a similar operation.
  • Do not start the engine.

(a) According to the display on the GTS, initialize the estimated thermal degradation value.

Powertrain > Engine > Utility

Tester Display

ATF Thermal Degradation Estimate Reset