CONTINUOUSLY VARIABLE TRANSAXLE SYSTEM, Diagnostic DTC:P0842 and P0843

DTC Code DTC Name
P0842 Transmission Fluid Pressure Sensor/Switch "A" Circuit Low
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

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

  1. 2 seconds or more after engine start

  2. Short in oil pressure sensor circuit

  3. 0.5 seconds

  4. 1-trip detection logic

  • Harness or connector

  • Oil pressure sensor

  • ECM

Comes on (w/ OBD)

Does not come on (w/o OBD)

DTC stored

P0843

Transmission Fluid Pressure Sensor/Switch "A" Circuit High

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

  1. 2 seconds or more after engine start

  2. Open or short to B+ in oil pressure sensor circuit

  3. 0.5 seconds

  4. 1-trip detection logic

  • Harness or connector

  • Oil pressure sensor

  • ECM

Comes on (w/ OBD)

Does not come on (w/o OBD)

DTC stored

MONITOR DESCRIPTION

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

WIRING DIAGRAM

C277073E06

CAUTION / NOTICE / HINT

Note:

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

    Click here

  • Check that no DTCs are stored after performing initialization.

    Click here

PROCEDURE

  1. READ VALUE USING GTS (A/T OIL PRESSURE)

    CAUTION:

    The 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.

    Note:

    • This test must be conducted after checking and confirming that the engine is operating normally.

    • Perform this test while the CVT fluid temperature is between 50 and 100°C (122 and 212°F).

    • Perform this test with the A/C off.

    • Do not perform the stall speed test for longer than 5 seconds.

    1. Warm up the engine.

    2. Fully apply the parking brake and chock all 4 wheels.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

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

      Powertrain > Engine and ECT > Active Test

      Tester Display

      Connect the TC and TE1

    7. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary.

    8. In accordance with the display on the GTS, 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:

      • 3.1 to 4.5 MPa (31.6 to 45.9 kgf/cm2, 450 to 653 psi): D position stall speed test

      • 2.1 to 4.5 MPa (21.4 to 45.9 kgf/cm2, 305 to 653 psi): R position stall speed test

      -

      Powertrain > Engine and ECT > Data List

      Tester Display

      A/T Oil Pressure

    Result

    Result

    Proceed to

    Data display is not within Normal Condition range

    A

    Data display is within Normal Condition range

    B
    B

    REPLACE ECMClick here

    A

  2. CHECK HARNESS AND CONNECTOR (OIL PRESSURE SENSOR - ECM)

    1. Disconnect the B32 oil pressure sensor connector.

    2. Disconnect the B93 ECM connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      B32-1 (E2) - B93-109 (EPTO)

      Always

      Below 1 Ω

      B32-2 (PTO) - B93-79 (PTO)

      Always

      Below 1 Ω

      B32-3 (VC) - B93-110 (VCPT)

      Always

      Below 1 Ω

      B32-1 (E2) or B93-109 (EPTO) - Body ground and other terminals

      Always

      10 kΩ or higher

      B32-2 (PTO) or B93-79 (PTO) - Body ground and other terminals

      Always

      10 kΩ or higher

      B32-3 (VC) or B93-110 (VCPT) - Body ground and other terminals

      Always

      10 kΩ or higher

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      B93-79 (PTO) - Body ground

      Ignition switch ON

      Below 1 V

      B32-2 (PTO) - Body ground

      Ignition switch ON

      Below 1 V

    Result

    Proceed to

    OK

    NG
    NG

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

    OK

  3. CHECK ECM (VCPT TERMINAL VOLTAGE)

    1. C125747C31

      *a

      Front view of wire harness connector

      (to Oil Pressure Sensor)

      Disconnect the oil pressure sensor connector.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      B32-3 (VC) - B32-1 (E2)

      Ignition switch ON

      4.75 to 5.25 V

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE ECMClick here

    OK

  4. REPLACE OIL PRESSURE SENSOR

    1. Replace the oil pressure sensor.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    PERFORM INITIALIZATION

    Click here

  5. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    PERFORM INITIALIZATION

    Click here

  6. REPLACE ECM

    1. Replace the ECM.

      Click here

    Result

    Proceed to

    NEXT
    NEXT

    PERFORM INITIALIZATION

    Click here