AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:B1417/17

DESCRIPTION

The rear air conditioning harness (rear evaporator temperature sensor) is installed on the evaporator in the rear air conditioning unit to detect the temperature of the cooled air that has passed through the evaporator and to control the rear air conditioner. It sends signals to the air conditioning amplifier. The signals change in accordance with the resistance of the rear air conditioning harness (rear evaporator temperature sensor). As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases. The air conditioning amplifier applies a voltage (5 V) to the rear air conditioning harness (rear evaporator temperature sensor) and reads voltage changes as changes in the resistance of the rear air conditioning harness (rear evaporator temperature sensor). This sensor is used for frost prevention.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER (R-EVAP TEMP SEN)

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch on (IG) and turn the intelligent tester main switch on.

   3. Select the item below in the Data List, and read the value displayed on the intelligent tester.

      Data List / Air Conditioner:

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      R-Evap Temp Sen	Rear evaporator temperature sensor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F)	Actual rear evaporator temperature is displayed	Open circuit: -29.7°C (-21.46°F) Short circuit: 59.55°C (139.19°F)

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

      Result
      Result Proceed to NG A OK (Checking from PROBLEM SYMPTOMS TABLE) B OK (Checking from DTC) C

   
   

   B

   PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   C

   REPLACE AIR CONDITIONING AMPLIFIER Click here

   A

2. INSPECT REAR AIR CONDITIONING HARNESS (REAR EVAPORATOR TEMPERATURE SENSOR)

   
   

   1. 

      Remove the rear air conditioning harness.

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

      Standard resistance

      Tester Connection Condition Specified Condition N11-7 (-) - N11-8 (+) -10°C (14°F) 7.30 to 9.10 kΩ N11-7 (-) - N11-8 (+) -5°C (23°F) 5.65 to 6.95 kΩ N11-7 (-) - N11-8 (+) 0°C (32°F) 4.40 to 5.35 kΩ N11-7 (-) - N11-8 (+) 5°C (41°F) 3.40 to 4.15 kΩ N11-7 (-) - N11-8 (+) 10°C (50°F) 2.70 to 3.25 kΩ N11-7 (-) - N11-8 (+) 15°C (59°F) 2.14 to 2.58 kΩ N11-7 (-) - N11-8 (+) 20°C (68°F) 1.71 to 2.05 kΩ N11-7 (-) - N11-8 (+) 25°C (77°F) 1.38 to 1.64 kΩ N11-7 (-) - N11-8 (+) 30°C (86°F) 1.11 to 1.32 kΩ

      Note

      
      

      • Touching the thermistor even slightly may change the resistance value. Be sure to hold the connector of the thermistor.

      • When measuring, the thermistor temperature must be the same as the ambient temperature.

      Tech Tips

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

   
   

   NG

   REPLACE REAR AIR CONDITIONING HARNESS

   OK

3. CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)

   
   

   1. 

      Disconnect the N11 rear air conditioning harness connector.

   2. Disconnect the D34 amplifier connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition N11-8 (+) - D34-4 (TEC) Always Below 1 Ω N11-7 (-) - D34-19 (SGND) Always Below 1 Ω

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE AIR CONDITIONING AMPLIFIER Click here