DTC    B1411/11    Room Temperature Sensor Circuit

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DESCRIPTION

The room temperature sensor is installed in the instrument panel to detect the room temperature and control the air conditioner "AUTO" mode. The resistance of the room temperature sensor changes in accordance with the room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the room temperature sensor and reads voltage changes as the resistance of the room temperature sensor changes. This sensor also sends the appropriate signals to the A/C amplifier. The room temperature sensor is integrated with the room humidity sensor.

DTC No.
DTC Detection Condition
Trouble Area
B1411/11
Open or short in room temperature sensor circuit
  1. Room temperature sensor
  2. Harness and connector between room temperature sensor and A/C amplifier
  3. A/C amplifier

WIRING DIAGRAM


E108199E01


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and push the intelligent tester main switch on.

  1. Select the item below in the Data List, and read the display on the intelligent tester.

    A/C amplifier: 
    Item
    		Measurement Item / Display
    (Range)
    		Normal Condition
    		Diagnostic Note
    Room Temperature Sensor
    (Room Temp)
    		Room temperature sensor /
    Min.: -6.5°C (20.3°F)
    Max.: 57.25°C (135.05°F)
    		Actual room temperature is displayed
    		Open in circuit: -6.5°C (20.3°F)
    Short in circuit: 57.25°C (135.05°F)

    OK:
    The display is as specified in the normal condition.


Result: 
NG
A
OK (Checking from the PROBLEM SYMPTOMS TABLE)
B
OK (Checking from the DTC)
C


B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER
A


2.INSPECT ROOM TEMPERATURE SENSOR
E106662E05

  1. Remove the room temperature sensor.

  1. Measure the resistance of the sensor.

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

    NOTICE:
    1. Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
    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).



NG
REPLACE ROOM TEMPERATURE SENSOR
OK


3.CHECK WIRE HARNESS (ROOM TEMPERATURE SENSOR - A/C AMPLIFIER)
E106868E03

  1. Disconnect the L33 room temperature sensor connector.

  1. Disconnect the L52 A/C amplifier connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    L33-1 (+) - L52-16 (TR)
    		Always
    		Below 1 Ω
    L33-2 (-) - L52-19 (SG-1)
    		Always
    		Below 1 Ω
    L52-16 (TR) - Body ground
    		Always
    		10 kΩ or higher
    L52-19 (SG-1) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER