Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001GYSO
Model Year Start: 2020 Model: Corolla Hatchback Prod Date Range: [01/2019 - 11/2022]
Title: K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: P0842,P0843; Transmission Fluid Pressure Sensor/Switch "A" Circuit Low; 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]

DTC

P0842

Transmission Fluid Pressure Sensor/Switch "A" Circuit Low

DTC

P0843

Transmission Fluid Pressure Sensor/Switch "A" Circuit High

DESCRIPTION

The ECM performs learning control for the belt clamping pressure based on the belt clamping pressure signal, which is output by the oil pressure sensor.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0842

Transmission Fluid Pressure Sensor/Switch "A" Circuit Low

When 2 seconds or more have elapsed since engine start, there is a short to ground in the oil pressure sensor circuit for 0.5 seconds (1-trip detection logic).

  • Wire harness or connector
  • Oil pressure sensor
  • ECM

Comes on

DTC stored

P0843

Transmission Fluid Pressure Sensor/Switch "A" Circuit High

When 2 seconds or more have elapsed since engine start, there is an open or a short to +B in the oil pressure sensor circuit for 0.5 seconds (1-trip detection logic).

  • Wire harness or connector
  • Oil pressure sensor
  • ECM

Comes on

DTC stored

MONITOR DESCRIPTION

These DTCs indicate an open or short in the oil pressure sensor circuit. If there is an open or short in the oil pressure sensor circuit, the ECM detects the malfunction, illuminates the MIL and stores a DTC.

MONITOR STRATEGY

Related DTCs

P0842: Oil pressure sensor / Range check (Low voltage)

P0843: Oil pressure sensor / Range check (High voltage)

Required sensors/Components

Oil pressure sensor

Frequency of operation

Continuous

Duration

0.5 seconds

MIL operation

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not present

None

Starter

OFF

Time after starter ON to OFF

2 seconds or more

Battery voltage

8 V or more

Time after battery voltage is 8 V or more

0.5 seconds or more

Write inhibit

Permit

Time after write status forbiddance to permit

0.5 seconds or more

Ignition switch

ON

Time after ignition switch OFF to ON

0.5 seconds or more

TYPICAL MALFUNCTION THRESHOLDS

P0842:

Oil pressure sensor output voltage

Less than 0.28 V

P0843:

Oil pressure sensor output voltage

More than 4.9 V

COMPONENT OPERATING RANGE

Oil pressure sensor output voltage

0.28 to 4.9 V

CONFIRMATION DRIVING PATTERN

HINT:

  • After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
  • When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: DTC CHECK / CLEAR

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON and turn the Techstream on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the ignition switch off and wait for 2 minutes or more.
  5. Turn the ignition switch to ON and turn the Techstream on.
  6. Start the engine and wait for 5 seconds or more. [*1]

    HINT:

    [*1]: Normal judgment procedure.

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

  7. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  8. Input the DTC: P0842 or P0843.
  9. Check the DTC judgment result.

    Techstream 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

    N/A

    • Unable to perform DTC judgment
    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

  • Do not perform a stall test if there are any people or objects near the vehicle.
  • The vehicle could begin moving suddenly, resulting in a serious accident.
  • Do not perform a stall test if any wheel chocks are out of position.
  • The vehicle could begin moving suddenly, resulting in a serious accident.
  • Do not perform the stall test on a slippery or low-friction surface that could allow the tires to spin.
  • The vehicle could begin moving suddenly, resulting in a serious accident.

NOTICE:

  • Perform the universal trip to clear permanent DTCs.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: DTC CHECK / CLEAR

  • Perform initialization when parts related to the continuously variable transaxle system are replaced.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: INITIALIZATION

  • Check that no DTCs are stored after performing initialization.

    Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: DTC CHECK / CLEAR

PROCEDURE

1.

READ VALUE USING TECHSTREAM (A/T OIL PRESSURE)

CAUTION:

A stall speed test should always be performed with at least 2 people. One person should observe the condition of the wheels and wheel chocks while the other is performing the test.

NOTICE:

  • This test must be performed after checking and confirming that the engine is normal.
  • Perform this test with the CVT fluid temperature between 50 and 100°C (122 and 212°F).
  • Perform this test with the air conditioning off.
  • Do not perform the stall speed test for more than 5 seconds.
  • When performing the stall speed test repeatedly, wait for 15 seconds or more between tests.
  • w/ Electric Parking Brake System:

    Perform this test with the AUTO function (shift-linked function) of the electric parking brake system off.

(a) Warm up the engine.

(b) Fully apply the parking brake and chock all 4 wheels.

HINT:

w/ Electric Parking Brake System:

When the parking brake indicator (red) is illuminated after the electric parking brake switch (electric parking brake switch assembly) has been pulled to the lock side, the maximum amount of braking force is applied if the electric parking brake switch (electric parking brake switch assembly) is pulled to the lock side one more time.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / Engine and ECT / Active Test / Connect the TC and TE1.

Powertrain > Engine and ECT > Active Test

Active Test Display

Connect the TC and TE1

Data List Display

A/T Oil Pressure

(g) According to the display on the Techstream, perform the Active Test.

(h) According to the display on the Techstream, read the Data List.

Powertrain > Engine and ECT > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

A/T Oil Pressure

Secondary oil pressure value

Min.: -64 MPa

Max.: 63.998 MPa

Secondary oil pressure inspection:

  • 3.6 to 4.8 MPa (36.7 to 48.9 kgf/cm2, 522 to 696 psi): D position stall test
  • 3.7 to 4.8 MPa (37.7 to 48.9 kgf/cm2, 537 to 696 psi): R position stall test

-

Result

Proceed to

Data List value is normal

A

Data List value is not normal

B

B

GO TO STEP 3

A

2.

REPLACE ECM

(a) Replace the ECM.

Click here 2020 - 2023 MY Corolla [01/2019 - 11/2022]; 2ZR-FAE (ENGINE CONTROL): ECM: COMPONENTS

NEXT

PERFORM INITIALIZATION

3.

CHECK ECM (VCPT TERMINAL VOLTAGE)

(a) Disconnect the C72 oil pressure sensor connector.

*a

Front view of wire harness connector

(to Oil Pressure Sensor)

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

C72-3 (VC) - C72-1 (E2)

Ignition switch ON

4.75 to 5.25 V

(c) Connect the C72 oil pressure sensor connector.

NG

GO TO STEP 10

OK

4.

CHECK HARNESS AND CONNECTOR (OIL PRESSURE SENSOR - ECM)

(a) Disconnect the C72 oil pressure sensor connector.

(b) Disconnect the C77 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C72-2 (PTO) - C77-79 (PTO)

Always

Below 1 Ω

C72-2 (PTO) or C77-79 (PTO) - Body ground and other terminals

Always

10 kΩ or higher

(d) Connect the C77 ECM connector.

(e) Connect the C72 oil pressure sensor connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (OIL PRESSURE SENSOR - ECM)

OK

5.

REPLACE OIL PRESSURE SENSOR

(a) Replace the oil pressure sensor.

Click here 2020 MY Corolla Corolla Hatchback [01/2019 - 03/2019]; K313 (CVT): OIL PRESSURE SENSOR: COMPONENTS 2020 - 2023 MY Corolla Corolla Hatchback [03/2019 - 11/2022]; K313 (CVT): OIL PRESSURE SENSOR: COMPONENTS

NEXT

6.

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Engine and ECT > Clear DTCs

NEXT

7.

PERFORM INITIALIZATION

(a) Using the Techstream, perform Reset Memory, Deceleration Sensor Zero Point Calibration and CVT Oil Pressure Calibration.

Click here 2020 - 2023 MY Corolla Corolla Hatchback [01/2019 - 11/2022]; K313 (CVT): CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM: INITIALIZATION

NEXT

8.

CHECK DTC OUTPUT

(a) Perform a road test.

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

Powertrain > Engine and ECT > Trouble Codes

(f) Read the DTCs using the Techstream.

Result

Proceed to

DTCs are not output

A

DTC P0842 or P0843 is output

B

A

END

B

9.

REPLACE ECM

(a) Replace the ECM.

Click here 2020 - 2023 MY Corolla [01/2019 - 11/2022]; 2ZR-FAE (ENGINE CONTROL): ECM: COMPONENTS

NEXT

PERFORM INITIALIZATION

10.

CHECK HARNESS AND CONNECTOR (OIL PRESSURE SENSOR - ECM)

(a) Disconnect the C72 oil pressure sensor connector.

(b) Disconnect the C77 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C72-3 (VC) - C77-110 (VCPT)

Always

Below 1 Ω

C72-1 (E2) - C77-109 (EPTO)

Always

Below 1 Ω

C72-3 (VC) or C77-110 (VCPT) - Body ground and other terminals

Always

10 kΩ or higher

C72-1 (E2) or C77-109 (EPTO) - Body ground and other terminals

Always

10 kΩ or higher

(d) Connect the C77 ECM connector.

(e) Connect the C72 oil pressure sensor connector.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (OIL PRESSURE SENSOR - ECM)

OK

11.

REPLACE ECM

(a) Replace the ECM.

Click here 2020 - 2023 MY Corolla [01/2019 - 11/2022]; 2ZR-FAE (ENGINE CONTROL): ECM: COMPONENTS

NEXT

PERFORM INITIALIZATION