AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:B1411/11

DESCRIPTION

The front room temperature sensor for the front seat 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 front room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the front room temperature sensor and reads voltage changes as the resistance of the front room temperature sensor changes. This sensor also sends the appropriate signals to the air conditioning amplifier assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER (FRONT ROOM TEMPERATURE SENSOR)

   
   

   1. Use the Data List to check if the front room temperature sensor is functioning properly.

      Air Conditioner

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Room Temperature Sensor	Front room temperature sensor / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F)	Actual room temperature for front seat displayed	Open in the circuit: -6.5°C (20.3°F). Short in the circuit: 57.25°C (135.05°F).

      OK
      The display is as specified in the normal condition.

   
   

   NG

   INSPECT ROOM TEMPERATURE SENSOR Click here

   OK

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

2. INSPECT ROOM TEMPERATURE SENSOR

   

   
   

   1. Remove the front room temperature sensor Click here.

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

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

      Note

      
      

      • 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.

      Tech Tips

      As the temperature increases, the resistance decreases (see the graph).

   
   

   NG

   REPLACE FRONT ROOM TEMPERATURE SENSOR Click here

   OK

3. CHECK HARNESS AND CONNECTOR (FRONT ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)

   
   

   1. 

      w/ Rear Heater

      
      

      1. Disconnect the E32 sensor connector.

      2. Disconnect the E35 amplifier connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition E32-1 (+) - E35-9 (TR) Always Below 1 Ω E32-2 (-) - E35-32 (SG-1) E35-9 (TR) - Body ground Always 10 kΩ or higher E35-32 (SG-1) - Body ground

   2. 

      w/o Rear Heater

      
      

      1. Disconnect the E32 sensor connector.

      2. Disconnect the E81 amplifier connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition E32-1 (+) - E81-29 (TR) Always Below 1 Ω E32-2 (-) - E81-34 (SG-1) E81-29 (TR) - Body ground Always 10 kΩ or higher E81-34 (SG-1) - Body ground

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here