AUTOMATIC TRANSMISSION SYSTEM (for 1KD-FTV), 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. 2 ATF temperature sensor is on the transmission, just in front of the oil cooler inlet pipeline.

If the TCM detects an abnormally high ATF temperature near this sensor, it illuminates the warning light.

Tech Tips


  • ATF temperature rises quickly when towing, climbing hills, in traffic, etc.

  • If the No. 2 ATF temperature sensor becomes short-circuited, the signal that indicates the ATF temperature is 150°C (302°F) or higher is input in the TCM.

Vehicle conditions when the sensor is normal and when the sensor is short-circuited are indicated in the table below.

No. 2 ATF Temperature Sensor State Detection Condition Symptom Recovery Condition
Sensor is normal

  • ATF temperature more than 150°C (302°F)

  • ATF temperature warning light remains ON

  • ATF temperature less than 135°C (275°F)*2

  • ATF temperature more than 130°C (266°F)

  • Shift point too high

  • ATF temperature less than 110°C (230°F)

  • When the conditions (a) and (b) are satisfied


    1. ATF temperature more than 130°C (266°F)


    1. Engine coolant temperature more than 95°C (203°F)

  • Lock-up at 3rd gear*1

  • ATF temperature less than 110°C (230°F)*2 and engine coolant temperature more than 95°C (203°F)
Sensor is short-circuited

  • Any conditions

  • ATF temperature warning light remains ON

  • Shift point too high

  • Symptoms still occur

  • Engine coolant temperature more than 95°C (203°F)

  • Lock-up at 3rd gear*1

  • Symptoms still occur

Tech Tips

*1: When ATF temperature is normal, transmission lock-up occurs in 5th gear with the shift lever on D, and 4th gear with the shift lever on 4.

*2: When ATF temperature is in the normal range, it decreases to less than 135°C (275°F) within 5 minutes with the shift lever on P or N in an idling state.

DTC Code DTC Detection Condition Trouble Area
P2740

  • (a) and (b) are detected momentarily within 0.5 sec. when neither P2742 nor P2743 are detected (1 trip detection logic):


    1. No. 2 ATF temperature sensor resistance is less than 25 Ω

    2. No. 2 ATF temperature sensor resistance is more 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. 2 ATF temperature sensor circuit

  • No. 2 ATF temperature sensor

  • TCM
P2742 No. 2 ATF temperature sensor resistance is less than 25 Ω for 0.5 sec. or more (1 trip detection logic)

  • Short in No. 2 ATF temperature sensor circuit

  • No. 2 ATF temperature sensor

  • TCM
P2743

No. 2 ATF temperature sensor resistance is more than 156 kΩ when 15 minutes or more have passed after the engine start

DTC is detected for 0.5 sec. or more (1 trip detection logic)

  • Open in No. 2 ATF temperature sensor circuit

  • No. 2 ATF temperature sensor

  • TCM

MONITOR DESCRIPTION

ATF temperature sensor converts ATF temperature to an electrical resistance value. Based on the resistance, the TCM determines the ATF temperature, and the TCM detects an open or short in the ATF temperature circuit. If the resistance value of the ATF temperature is less than 25 Ω*1 or more than 156 kΩ*2, the TCM interprets this as a fault in the ATF sensor or wiring. The TCM will illuminate the MIL and store the DTC.

Tech Tips


  • *1: 150°C (302°F) or more 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.

WIRING DIAGRAM

Refer to DTC P0710 Click here.

INSPECTION PROCEDURE


  1. DATA LIST

    Tech Tips

    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 / ECT / Data List.

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

      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.: 215°C (419°F)

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

      • With engine cold: Equal to ambient temperature

      		 If the value is -40°C (-40°F) or 215°C (419°F), the No. 1 ATF temperature sensor circuit is open or shorted.

      Tech Tips

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

      When DTC P2743 is stored 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

PROCEDURE


  1. INSPECT TRANSMISSION WIRE (NO. 2 ATF TEMPERATURE SENSOR)

    A01E0VEE52

    1. Disconnect the E1 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-) - 9 (OT2+) Always 25 Ω to 156 kΩ
      1 (OT2-) - Body ground Always 10 kΩ or higher
      9 (OT2+) - Body ground Always 10 kΩ or higher

      Tech Tips

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

      Resistance (Reference)
      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 TRANSMISSION WIRE

    OK

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

    A01E2RLE32

    1. Disconnect the T19 TCM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      T19-24 (THO2) - T19-23 (E2) Always 79 Ω to 156 kΩ
      T19-24 (THO2) - Body ground Always 10 kΩ or higher
      T19-23 (E2) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE TCM