AIR CONDITIONING SYSTEM, Diagnostic DTC:B1381

DTC Code DTC Name
B1381 Internal Condenser Refrigerant Temperature Sensor Circuit

DESCRIPTION

The internal condenser temperature sensor is installed to the outlet pipe of the No. 2 condenser assembly and detects the refrigerant temperature for heat pump air-conditioning control. The resistance of the internal condenser temperature sensor changes depending on the refrigerant temperature of the No. 2 condenser assembly outlet. When the temperature becomes low, the resistance of the thermistor increases. When the temperature becomes high, the resistance decreases.

The heat pump ECU assembly applies a voltage (5 V) to the internal condenser temperature sensor and reads voltage changes due to changes in the resistance of the internal condenser temperature sensor.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory
B1381 Internal Condenser Refrigerant Temperature Sensor Circuit Open or short in internal condenser temperature sensor circuit

  • Internal condenser temperature sensor

  • Harness or connector

  • Heat pump ECU assembly

Memorized

(4 sec. or more)*

WIRING DIAGRAM

A003OHXE07
*a TPL
*b TFG
*c Internal Condenser Temperature Sensor
*d Heat Pump ECU Assembly

PROCEDURE


  1. CHECK FOR DTC


    1. Check for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1381 is output A
      DTC B1381, B14A7 are output B

    B

    CHECK HARNESS AND CONNECTOR (INTERNAL CONDENSER TEMPERATURE SENSOR - HEAT PUMP ECU ASSEMBLY) Click here

    A

  2. INSPECT INTERNAL CONDENSER TEMPERATURE SENSOR

    A003KT1C02
    *a

    Component without harness connected

    (Internal Condenser Temperature Sensor)
    *b Sensing Portion
    *c Resistance (kΩ)
    *d Temperature (°C (°F))
    *e Allowable Range

    1. Remove the internal condenser temperature sensor.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (-) - 2 (TMP1) 10°C (50°F) 189.0 to 197.8 kΩ
      15°C (59°F) 149.1 to 155.4 kΩ
      20°C (68°F) 118.3 to 123.0 kΩ
      25°C (77°F) 94.5 to 97.9 kΩ
      30°C (86°F) 76.0 to 78.5 kΩ
      35°C (95°F) 61.5 to 63.3 kΩ
      40°C (104°F) 50.0 to 51.4 kΩ
      45°C (113°F) 41.0 to 41.9 kΩ
      50°C (122°F) 33.7 to 34.4 kΩ
      55°C (131°F) 27.8 to 28.4 kΩ
      60°C (140°F) 23.1 to 23.6 kΩ

      Note


      • Hold the sensor only by its connector. Touching the sensing portion may change the resistance value.

      • When measuring, the sensor temperature must be the same as the ambient temperature.

      Tech Tips

      As the temperature increases, the resistance decreases (see the graph).

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INTERNAL CONDENSER TEMPERATURE SENSOR Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (INTERNAL CONDENSER TEMPERATURE SENSOR - HEAT PUMP ECU ASSEMBLY)


    1. Disconnect the A42 heat pump ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I71-1 (-) - A42-7 (TPL) Always Below 1 Ω
      I71-1 (-) or A42-7 (TPL) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEAT PUMP ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  4. CHECK HARNESS AND CONNECTOR (INTERNAL CONDENSER TEMPERATURE SENSOR - HEAT PUMP ECU ASSEMBLY)


    1. Disconnect the I71 internal condenser temperature sensor connector.

    2. Disconnect the A42 heat pump ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I71-2 (TMP1) - A42-34 (TFG) Always Below 1 Ω
      I71-2 (TMP1) or A42-34 (TFG) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HEAT PUMP ECU ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR