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AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P2742, P2743

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

Refer to DTC P2741 (Click here).

DTC Code DTC Detection Condition Trouble Area
P2742 No. 1 ATF temperature sensor voltage is below 0.142 V 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)

  • ECM
P2743 When 15 minutes or more have elapsed after the engine is started, No. 1 ATF temperature sensor voltage is higher than 4.915 V 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)

  • ECM
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MONITOR DESCRIPTION

The ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature and detects an open or short in the ATF temperature sensor circuit. If the output voltage of the ATF temperature sensor is below 0.142 V*1 or higher than 4.915 V*2, the ECM interprets this as a fault in the ATF temperature sensor or wiring. The ECM will illuminate the MIL and store the DTC.

Tip:

  • *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 intelligent tester display.

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WIRING DIAGRAM

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INSPECTION PROCEDURE


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  1. DATA LIST

    Tip:

    Using the intelligent tester 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 intelligent tester to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the intelligent tester on.

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

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

      Table 1. 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.
      Tip:

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

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

      Check the temperature displayed on the tester 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
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PROCEDURE


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    INSPECT TRANSMISSION WIRE (NO. 1 ATF TEMPERATURE SENSOR)


    1. A01DUUDE01

      Disconnect the C58 transmission wire connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (OT2+) - 5 (OT2-) Always 79 Ω to 156 kΩ
      1 (OT2+) - Body ground Always 10 kΩ or higher
      5 (OT2-) - Body ground Always 10 kΩ or higher
      Tip:

      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
      Table 2. Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)

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    CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)


    1. A01DPQRE07

      Disconnect the C62 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C62-18 (THO1) - C62-17 (ETHO) Always 79 Ω to 156 kΩ
      C62-18 (THO1) - Body ground Always 10 kΩ or higher
      C62-17 (ETHO) - Body ground Always 10 kΩ or higher
      Table 3. Text in Illustration
      *a

      Rear view of wire harness connector

      (to ECM)

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    REPLACE ECMClick here

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

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    REPAIR OR REPLACE HARNESS OR CONNECTOR