DTC    P0840    Transmission Fluid Pressure Sensor/Switch "A" Circuit

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

DTC    P0843    Transmission Fluid Pressure Sensor/Switch "A" Circuit High

for Preparation Click here


DESCRIPTION

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

DTC No.
DTC Detection Condition
  1. Diagnosis Condition
  2. Malfunction Status
  3. Malfunction Time
  4. Other
Trouble Area
P0840
  1. 2 seconds or more after engine start
  2. Open or short in oil pressure sensor circuit
  3. 0.5 seconds
  4. 1-trip detection logic
  1. Open or short in oil pressure sensor circuit
  2. Oil pressure sensor
  3. ECM
P0842
  1. 2 seconds or more after engine start
  2. Short in oil pressure sensor circuit
  3. 0.5 seconds
  4. 1-trip detection logic
  1. Short in oil pressure sensor circuit
  2. Oil pressure sensor
  3. ECM
P0843
  1. 2 seconds or more after engine start
  2. Open in oil pressure sensor circuit
  3. 0.5 seconds
  4. 1-trip detection logic
  1. Open in oil pressure sensor circuit
  2. Oil pressure sensor
  3. ECM

MONITOR DESCRIPTION

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

WIRING DIAGRAM


C195848E02


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (A/T OIL PRESSURE)
  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the tester on.

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

  1. In accordance with the display on the tester, read the Data List.

    Tester Display
    Measurement Item/Range
    Normal Condition
    Diagnostic Note
    A/T Oil Pressure
    Secondary oil pressure value/
    min.: -0.625 MPa
    max.: 9.575 MPa
    Secondary oil pressure inspection (D position stall test)
    3.81 to 4.58 MPa
    -
    Result 
    Result
    Proceed to
    Data display is not within Normal Condition range
    A
    Data display is within Normal Condition range
    B



B
Go to step 6
A


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


    C193938E01
  1. Disconnect the oil pressure sensor connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:
    Tester Connection
    Condition
    Specified Condition
    B12-1 (E2) - B8-72 (EPTO)
    Always
    Below 1 Ω
    B12-2 (PTO) - B8-73 (PTO)
    Always
    Below 1 Ω
    B12-3 (VC) - B8-74 (VCPT)
    Always
    Below 1 Ω
    B8-72 (EPTO) - Body ground
    Always
    10 kΩ or higher
    B8-73 (PTO) - Body ground
    Always
    10 kΩ or higher
    B8-74 (VCPT) - Body ground
    Always
    10 kΩ or higher

    Text in Illustration 
    *1
    Front view of wire harness connector:
    (to Oil Pressure Sensor)
    *2
    Front view of wire harness connector:
    (to ECM)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT ECM (VCPT TERMINAL VOLTAGE)


    C193937E01
  1. Connect the ECM connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    Switch Condition
    Specified Condition
    B12-1 (E2) - B12-3 (VC)
    Ignition switch ON
    4.5 to 5.5 V

    Text in Illustration 
    *1
    Front view of wire harness connector:
    (to Oil Pressure Sensor)



NG
Go to step 6
OK


4.REPLACE OIL PRESSURE SENSOR
  1. Replace the oil pressure sensor (Click here).


NEXT


5.PERFORM INITIALIZATION

NOTICE:
  1. Performing reset memory/initialization will clear the learned values of both the yaw rate and acceleration sensor (deceleration sensor 0 point calibration) and the CVT oil pressure (CVT oil pressure calibration). Make sure to perform reset memory, yaw rate and acceleration sensor 0 point calibration, and CVT oil pressure calibration when replacing any of the parts shown in the following table:
    Replaced Part
    1. Continuously variable transaxle assembly
    2. ECM
    3. Oil pressure sensor
    4. Yaw rate and acceleration sensor
  2. After reset memory, always perform yaw rate and acceleration sensor (deceleration sensor 0 point) calibration first, and then the CVT oil pressure calibration.
  3. Always perform the 0 point calibration with the vehicle on level ground.
  4. Do not shake or vibrate the vehicle during the 0 point calibration.

  1. Using the intelligent tester, perform the reset memory, deceleration sensor 0 point calibration and CVT oil pressure calibration (Click here).

  1. Check for DTCs again (Click here).


NEXT

END 

6.REPLACE ECM
  1. Replace the ECM (Click here).


NEXT


7.PERFORM INITIALIZATION

NOTICE:
  1. Performing reset memory/initialization will clear the learned values of both the yaw rate and acceleration sensor (deceleration sensor 0 point calibration) and the CVT oil pressure (CVT oil pressure calibration). Make sure to perform reset memory, yaw rate and acceleration sensor 0 point calibration, and CVT oil pressure calibration when replacing any of the parts shown in the following table:
    Replaced Part
    1. Continuously variable transaxle assembly
    2. ECM
    3. Oil pressure sensor
    4. Yaw rate and acceleration sensor
  2. After reset memory, always perform yaw rate and acceleration sensor (deceleration sensor 0 point) calibration first, and then the CVT oil pressure calibration.
  3. Always perform the 0 point calibration with the vehicle on level ground.
  4. Do not shake or vibrate the vehicle during the 0 point calibration.

  1. Using the intelligent tester, perform the reset memory, deceleration sensor 0 point calibration and CVT oil pressure calibration (Click here).

  1. Check for DTCs again (Click here).


NEXT

END