AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0873

DTC Code DTC Name
P0873 Transmission Fluid Pressure Sensor / Switch "C" Circuit High

DESCRIPTION

The oil pressure switch, which is built into the valve body, detects the fluid pressure of the SL1 fluid pressure circuit. If shift solenoid valve SL1 is stuck ON, P0873 is output.

DTC No.

DTC Detection Condition


  1. Diagnosis Condition

  2. Malfunction Status

  3. Malfunction Time

  4. Other

 Trouble Area
P0873

  1. ECT is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and the vehicle is driven with the shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, transmission revolution sensors (NT, NC3, SP2), engine coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)

  2. When the actual gear is 6th to 8th gear, the oil pressure switch is ON

  3. Malfunction status occurs 2 times (1 trip)

  4. 2 trip detection logic

  • Shift solenoid valve SL1

  • Oil pressure switch

  • Transmission wire

  • Harness or connector

  • TCM

  • Valve body assembly

  • Automatic transmission assembly

WIRING DIAGRAM

Refer to DTC P0872 Click here.

INSPECTION PROCEDURE

Note

Perform registration and/or initialization when parts related to the automatic transmission are replaced Click here.

PROCEDURE


  1. READ VALUE USING GTS (TPS 1 SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / ECT / Active Test / Control the Shift Position.

      ECT
      Tester Display Test Part Control Range Diagnostic Note
      Control the Shift Position Operates the shift solenoid valves to allow gears to be selected manually

      • Press "→" button: Up-shift occurs

      • Press "←" button: Down-shift occurs

      Possible to check operation of the shift solenoid valves.

      [Vehicle Condition]


      • Vehicle speed: 50 km/h (31 mph) or less

    5. Select TPS 1 Switch in the Data List.

    6. While performing the "Control the Shift Position" Active Test, check TPS 1 Switch in the Data List.

      ECT
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      TPS 1 Switch

      Oil pressure switch status/

      ON or OFF

      • ON: Gear is 1st to 5th

      • OFF: Gear is 6th to 8th, or shift lever is in P, N or R

      		 -
      Result
      Result Proceed to
      When the engine is idling with the shift lever in P, N or R, ON is displayed for TPS 1 Switch on the Data List. A
      When the vehicle is being driven in a gear position between 6th and 8th or when the engine is idling with the shift lever in P, N or R, OFF is displayed for TPS 1 Switch on the Data List. B
      When the vehicle is being driven in a gear position between 6th and 8th, ON is displayed for TPS 1 Switch on the Data List. C

    B

    REPLACE TCM Click here

    C

    CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - TCM) Click here

    A

  2. CHECK OIL PRESSURE SWITCH CIRCUIT

    Tech Tips

    Before checking, perform visual and contact pressure checks on the TCM connectors.


    1. A01FGIIE01
      Text in Illustration
      *a

      Component with harness connected

      (TCM)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F72-9 (TPS1) - Body ground Engine switch off 10 kΩ or higher

    NG

    CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND) Click here

    OK

  3. INSPECT SHIFT SOLENOID VALVE SL1


    1. A01FI7WE21
      Text in Illustration
      *1 Shift Solenoid Valve SL1

      Remove the shift solenoid valve SL1 Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Terminal 1 of the shift solenoid valve SL1 - Terminal 2 20°C (68°F) 5.0 to 5.6 Ω

    3. Connect a positive (+) battery lead with a 21 W bulb to terminal 2 and a negative (-) battery lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.

      OK
      Valve moves and makes an operating sound.

    NG

    REPLACE SHIFT SOLENOID VALVE SL1 Click here

    OK

  4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY


    1. Check the transmission valve body assembly Click here.

      OK
      There is no foreign matter on each valve and they operate smoothly.

    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Click here

  5. CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND)


    1. A01FF0QE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to TCM)

      Disconnect the TCM connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      F72-9 (TPS1) - Body ground Engine switch off 10 kΩ or higher

    NG

    CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - TCM) Click here

    OK

  6. REPLACE TCM


    1. Replace the TCM Click here.


    NEXT

    PERFORM A/T CODE REGISTRATION Click here

  7. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - TCM)


    1. Disconnect the F73 transmission wire connector.

    2. Disconnect the F72 TCM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F73-17 (TPS1) - F72-9 (TPS1) Always Below 1 Ω
      F73-17 (TPS1) or F72-9 (TPS1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT TRANSMISSION WIRE (OIL PRESSURE SWITCH)


    1. A01FEP4E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Oil Pressure Switch Connector)
      *b

      Component without harness connected

      (Transmission Wire)
      *c Connector

      Disconnect the oil pressure switch connector Click here.

    2. Disconnect the transmission wire connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Oil pressure switch connector - 17 (TPS1) Always Below 1 Ω
      Oil pressure switch connector or 17 (TPS1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE TRANSMISSION WIRE Click here

    OK

    REPLACE OIL PRESSURE SWITCH Click here