СИСТЕМА АВТОМАТИЧЕСКОЙ ТРАНСМИССИИ С ЭЛЕКТРОННЫМ УПРАВЛЕНИЕМ, Diagnostic DTC:P2740, P2742, P2743

DTC Code DTC Name
P2740 Transmission Fluid Temperature Sensor "B" Circuit
P2742 Transmission Fluid Temperature Sensor "B" Circuit Low Input
P2743 Transmission Fluid Temperature Sensor "B" Circuit High Input

DESCRIPTION

The No. 1 ATF temperature sensor is installed in the transmission valve body assembly.

The TCM applies a voltage to the temperature sensor through terminal THO of the TCM. The sensor resistance changes with the ATF temperature. As the temperature becomes higher, the sensor resistance decreases. One terminal of the sensor is grounded so that the sensor resistance decreases and the voltage goes down as the temperature becomes higher.

The TCM calculates the fluid temperature based on the voltage signal.

DTC Code DTC Detection Condition Trouble Area
P2740

(a) and (b) are detected momentarily within 0.5 sec. when neither P2742 or P2743 are detected. (1-trip detection logic)


  • No. 1 ATF temperature sensor resistance is below 25 Ω.

  • No. 1 ATF temperature sensor resistance is higher than 156 kΩ.

Tech Tips

Within 0.5 sec., the malfunction switches from (a) to (b) or from (b) to (a).

  • Open or short in No. 1 ATF temperature sensor circuit

  • No. 1 ATF temperature sensor (transmission wire)

  • TCM
P2742 No. 1 ATF temperature sensor voltage is below 79 Ω for 0.5 sec. or more (1-trip detection logic).

  • Short in No. 1 ATF temperature sensor circuit

  • No. 1 ATF temperature sensor (transmission wire)

  • TCM
P2743 When 15 minutes or more have elapsed after the engine is started, No. 1 ATF temperature sensor voltage is higher than 156 kΩ for 0.5 sec. or more (1-trip detection logic).

  • Open in No. 1 ATF temperature sensor circuit

  • No. 1 ATF temperature sensor (transmission wire)

  • TCM

MONITOR DESCRIPTION

The No. 1 ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the TCM determines the ATF temperature and detects an open or short in the No. 1 ATF temperature sensor circuit. If the resistance value of the No. 1 ATF temperature sensor is below 79 Ω*1 or higher than 156 kΩ*2, the TCM interprets this as a fault in the No. 1 ATF temperature sensor or wiring. The TCM will illuminate the MIL and store the DTC.

Tech Tips


  • *1: 150°C (302°F) or higher is indicated regardless of the actual ATF temperature.

  • *2: -40°C (-40°F) is indicated regardless of the actual ATF temperature.

  • The ATF temperature can be checked on the GTS display.

WIRING DIAGRAM

A003BMPE03

INSPECTION PROCEDURE


  1. DATA LIST

    Tech Tips

    Using the GTS to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

    Note

    In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.


    1. Warm up the engine.

    2. Turn the ignition switch off.

    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 / ECT / Data List.

    7. According to the display on the GTS, read the Data List.

      Engine and ECT
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      A/T Oil Temperature 1

      No. 1 ATF temperature sensor value/

      Min.: -40°C (-40°F)

      Max.: 150°C (302°F)

      • After stall test: Approximately 80°C (176°F)

      • Equal to ambient temperature when engine cold

      		 If the value is -40°C (-40°F) or 150°C (302°F), the No. 1 ATF temperature sensor circuit is open or shorted.

      Tech Tips

      When DTC P2742 is output and the GTS output is 150°C (302°F) or higher, there is a short circuit.

      When DTC P2743 is output and the GTS output is -40°C (-40°F), there is an open circuit.

      Check the temperature displayed on the GTS in order to check if a malfunction exists.

      Temperature Displayed Malfunction
      -40°C (-40°F) Open circuit
      150°C (302°F) or higher Short circuit

PROCEDURE


  1. INSPECT TRANSMISSION WIRE (NO. 1 ATF TEMPERATURE SENSOR)


    1. A003DSGE18
      Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)

      Disconnect the transmission wire connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (OT+) - 5 (OT-) Always 79 Ω to 156 kΩ
      1 (OT+) - Body ground Always 10 kΩ or higher
      5 (OT-) - Body ground Always 10 kΩ or higher

      Tech Tips

      If the resistance is out of the specified range at any of the ATF temperatures shown in the table below, the driveability of the vehicle may decrease.

      Standard Resistance
      ATF Temperature Specified Condition
      10°C (50°F) 5 to 8 kΩ
      25°C (77°F) 2.5 to 4.5 kΩ
      110°C (230°F) 0.22 to 0.28 kΩ

    NG

    REPAIR OR REPLACE NO. 1 ATF TEMPERATURE SENSOR (TRANSMISSION WIRE)

    OK

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


    1. A003B4AE02
      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 Condition Specified Condition
      O1-25 (THO) - O1-23 (E2) Always 79 Ω to 156 kΩ
      O1-25 (THO) - Body ground Always 10 kΩ or higher
      O1-23 (E2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TCM