DTC    B1412/12    Ambient Temperature Sensor Circuit

for Preparation Click here


DESCRIPTION

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

DTC No.
DTC Detection Condition
Trouble Area
B1412/12
Open or short in ambient temperature sensor circuit
  1. Ambient temperature sensor
  2. Harness or connector between ambient temperature sensor and combination meter
  3. Combination meter
  4. CAN communication system
  5. A/C amplifier

WIRING DIAGRAM


E142534E04


INSPECTION PROCEDURE

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

  1. 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 TECHSTREAM
  1. Connect the Techstream to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the Techstream on.

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

  1. 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 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 SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)

C
REPLACE AIR CONDITIONING AMPLIFIER (Click here)
A


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


    E223629E01
  1. Disconnect the connector from the combination meter.

  1. 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

    HINT:
    As the temperature increases, the resistance decreases.
    Text in Illustration 
    *a
    Front view of wire harness connector
    (to Combination Meter)


NG
Go to step 5
OK


4.REPLACE COMBINATION METER
  1. Replace the combination meter (Click here).

    HINT:
    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.
  1. Check for DTCs.

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


B
REPLACE AIR CONDITIONING AMPLIFIER (Click here)
A

END 

5.INSPECT AMBIENT TEMPERATURE SENSOR
  1. Remove the ambient temperature sensor.



    E222722E03
  1. Disconnect the connector from the ambient temperature sensor.

  1. 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

    NOTICE:
    1. Hold the sensor only by its connector. Touching the sensor may change the resistance value.
    2. When measuring, the sensor temperature must be the same as the ambient temperature.

    HINT:
    As the temperature increases, the resistance decreases (see the graph).
    Text in Illustration 
    *a
    Component without harness connected
    (Ambient Temperature Sensor)
    *b
    Sensing Portion
    *c
    Resistance (kΩ)
    *d
    Allowable Range
    *e
    Temperature (°C (°F))


NG
REPLACE AMBIENT TEMPERATURE SENSOR (Click here)
OK

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