DESCRIPTION
The room temperature sensor is installed in the instrument panel to detect the
room temperature and control the heater and 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 air conditioning 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 air conditioning
amplifier.
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DTC Code
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DTC Detection Condition
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Trouble Area
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B1411/11
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Open or short in room temperature sensor circuit
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- Room temperature sensor
- Harness or connector between room temperature sensor and air conditioning
amplifier
- Air conditioning amplifier
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WIRING DIAGRAM
PROCEDURE
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1.
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READ VALUE USING TECHSTREAM (ROOM TEMPERATURE SENSOR)
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(a) Use the Data List to check if the room temperature sensor is functioning
properly.
Air Conditioner
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Tester Display
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Measurement Item / Range
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Normal Condition
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Diagnostic Note
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Room Temperature Sensor
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Room temperature sensor /
Min.: -6.5°C (20.3°F)
Max.: 57.25°C (135.05°F)
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Actual room temperature is displayed
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Open in circuit: -6.5°C (20.3°F)
Short in circuit: 57.25°C (135.05°F)
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OK:
The display is as specified in the normal condition.
Result
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Result
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Proceed to
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NG
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A
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OK (Checking from the PROBLEM SYMPTOMS TABLE)
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B
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OK (Checking from the DTC)
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C
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| B |
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PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
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| C |
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REPLACE AIR CONDITIONING AMPLIFIER
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| A |
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2.
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INSPECT ROOM TEMPERATURE SENSOR
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(a) Remove the room temperature sensor (see page
 ).
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
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Tester Connection
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Condition
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Specified Condition
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1 - 2
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10°C (50°F)
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3.00 to 3.73 kΩ
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15°C (59°F)
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2.45 to 2.88 kΩ
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20°C (68°F)
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1.95 to 2.30 kΩ
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25°C (77°F)
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1.60 to 1.80 kΩ
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30°C (86°F)
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1.28 to 1.47 kΩ
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35°C (95°F)
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1.00 to 1.22 kΩ
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40°C (104°F)
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0.80 to 1.00 kΩ
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45°C (113°F)
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0.65 to 0.85 kΩ
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50°C (122°F)
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0.50 to 0.70 kΩ
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55°C (131°F)
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0.44 to 0.60 kΩ
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60°C (140°F)
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0.36 to 0.50 kΩ
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NOTICE:
- Even slightly touching the sensor may change the resistance value. Be sure
to hold the connector of the sensor.
- 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 |
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REPLACE ROOM TEMPERATURE SENSOR
|
| OK |
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3.
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CHECK HARNESS AND CONNECTOR (ROOM TEMPERATURE SENSOR - AIR CONDITIONING
AMPLIFIER)
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(a) Disconnect the J16 sensor connector.
(b) Disconnect the J19 air conditioning amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
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Tester Connection
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Condition
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Specified Condition
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J16-1 - J19-29 (TR)
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Always
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Below 1 Ω
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J16-2 - J19-34 (SG-1)
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J16-1 or J19-29 (TR) - Body ground
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Always
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10 kΩ or higher
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J16-2 or J19-34 (SG-1) - Body ground
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| OK |
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REPLACE AIR CONDITIONING AMPLIFIER
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| NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR
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