AIR CONDITIONING SYSTEM, Diagnostic DTC:B1412/12

DTC Code DTC Name
B1412/12 Ambient Temperature Sensor Circuit

DESCRIPTION

This sensor detects the temperature outside the cabin and sends the appropriate signals to the A/C amplifier.

DTC No. DTC Detection Condition Trouble Area
B1412/12 Open or short in ambient temperature sensor circuit

  • Ambient temperature sensor

  • Harness or connector between ambient temperature sensor and combination meter

  • Combination meter

  • CAN communication system

  • A/C amplifier

WIRING DIAGRAM

A003SM2E09

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM (COMBINATION METER - A/C AMPLIFIER)


    1. Use the intelligent tester to check that the CAN communication system functions normally between the combination meter and the A/C amplifier.

      Result
      Result Proceed to
      CAN DTC is not output A
      CAN DTC is output B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the intelligent tester on.

    4. Enter the following menus: Body / Air Conditioner / Data List.

    5. Check the value(s) by referring to the table below.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note

      Ambient Temp Sensor

      (Ambi Temp Sens)

      		 Ambient temperature sensor / Min: -23.3°C (-9.94°F), Max: 65.95°C (150.71°F) Actual ambient temperature is displayed

      Open in circuit: -23.3°C (-9.94°F)

      Short in circuit: 65.95°C (150.71°F)
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to Problem Symptoms Table) B
      OK (When troubleshooting according to DTC) C

    B

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE A/C AMPLIFIER Click here

    A

  3. CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR CIRCUIT)


    1. A003RLOE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Combination Meter)

      Disconnect the E46 connector from the combination meter.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      E46-9 (TX1+) - E46-23 (TEMP)

      Outside temperature:

      25°C (77°F)

      		 1.60 to 1.80 kΩ
      E46-9 (TX1+) - E46-23 (TEMP)

      Outside temperature:

      40°C (104°F)

      		 0.80 to 1.00 kΩ

      Tech Tips

      As the temperature increases, the resistance decreases.

    3. Reconnect the connector to the combination meter.


    NG

    INSPECT AMBIENT TEMPERATURE SENSOR Click here

    OK

  4. REPLACE COMBINATION METER


    1. Replace the combination meter Click here.

      Tech Tips

      Since the combination meter cannot be inspected while it is removed from the vehicle, replace the combination meter with a known good one and check that the condition returns to normal.

    2. Check for DTCs.

      Result
      Result Proceed to
      DTC B1412 is not output A
      DTC B1412 is output B

    B

    REPLACE A/C AMPLIFIER Click here

    A

    END

  5. INSPECT AMBIENT TEMPERATURE SENSOR


    1. A003T7VE01
      Text in Illustration
      *1

      Component without harness connected

      (Ambient Temperature Sensor)
      *2 Sensing Portion
      *3 Resistance (kΩ)
      *4 Allowable Range
      *5 Temperature °C (°F)

      Disconnect the A23 connector from the ambient temperature sensor.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A23-1 - A23-2 10°C (50°F) 3.00 to 3.73 kΩ
      A23-1 - A23-2 15°C (59°F) 2.45 to 2.88 kΩ
      A23-1 - A23-2 20°C (68°F) 1.95 to 2.30 kΩ
      A23-1 - A23-2 25°C (77°F) 1.60 to 1.80 kΩ
      A23-1 - A23-2 30°C (86°F) 1.28 to 1.47 kΩ
      A23-1 - A23-2 35°C (95°F) 1.00 to 1.22 kΩ
      A23-1 - A23-2 40°C (104°F) 0.80 to 1.00 kΩ
      A23-1 - A23-2 45°C (113°F) 0.65 to 0.85 kΩ
      A23-1 - A23-2 50°C (122°F) 0.50 to 0.70 kΩ
      A23-1 - A23-2 55°C (131°F) 0.44 to 0.60 kΩ
      A23-1 - A23-2 60°C (140°F) 0.36 to 0.50 kΩ

      Note


      • Hold the sensor only by its connector. Touching the sensor 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).


    NG

    REPLACE AMBIENT TEMPERATURE SENSOR Click here

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (COMBINATION METER - AMBIENT TEMPERATURE SENSOR)