DTC    B1412    Ambient Temperature Sensor Circuit

for Preparation Click here


DESCRIPTION

The ambient temperature sensor is installed in front of the condenser. 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
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. A/C amplifier
  5. CAN communication system

WIRING DIAGRAM


E147386E08


INSPECTION PROCEDURE

1.CHECK CAN COMMUNICATION SYSTEM

  1. Use the Techstream to check if the CAN communication system is functioning normally.

    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 the DTC output)
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)


    E145299E05

  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)
    		25°C (77°F)
    		1.60 to 1.80 kΩ
    E46-9 (TX1+) - E46-23 (TEMP)
    		40°C (104°F)
    		0.80 to 1.00 kΩ
    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Combination Meter)


NG
Go to step 5
OK


4.INSPECT COMBINATION METER

  1. Temporarily replace the combination meter with a known good one (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

REPLACE COMBINATION METER (Click here)  

5.INSPECT AMBIENT TEMPERATURE SENSOR

  1. Remove the ambient temperature sensor.



    E222722E05

  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 (AMBIENT TEMPERATURE SENSOR - COMBINATION METER)