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

DESCRIPTION

The No. 2 air conditioning harness assembly (rear evaporator temperature sensor) is installed on the evaporator in the rear air conditioning unit to detect the cooled air temperature that has passed through the evaporator and to control the rear air conditioning. It sends signals to the air conditioning amplifier assembly. The signals change in accordance with the resistance of the No. 2 air conditioning harness assembly (rear evaporator temperature sensor). As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases. The air conditioning amplifier assembly applies a voltage (5 V) to the No. 2 air conditioning harness assembly (rear evaporator temperature sensor) and reads voltage changes as the resistance of the No. 2 air conditioning harness assembly (rear evaporator temperature sensor) changes. This sensor is used for frost prevention.

WIRING DIAGRAM

*a	Rear Evaporator Temperature Sensor
*b	No. 2 Air Conditioning Harness Assembly
*c	Air Conditioning Amplifier Assembly

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER (REAR EVAPORATOR TEMPERATURE SENSOR)

   
   

   1. Use the Data List to check if the rear evaporator temperature sensor is functioning properly Click here.

      Air Conditioner

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

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

      Result

      Result	Proceed to
      OK (When troubleshooting according to problem symptoms table)	A
      OK (When troubleshooting according to the DTC)	B
      NG	C

   
   

   A

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   B

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   C

2. INSPECT NO. 2 AIR CONDITIONING HARNESS ASSEMBLY (REAR EVAPORATOR TEMPERATURE SENSOR)

   
   

   1. Remove the No. 2 air conditioning harness assembly (rear evaporator temperature sensor) Click here.

      

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

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

      Text in Illustration

      *a	Sensing Portion
      *b	Resistance
      *c	Allowable Range
      *d	Temperature

      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 (refer to the graph).

   
   

   NG

   REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY (REAR EVAPORATOR TEMPERATURE SENSOR) Click here

   OK

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

   
   

   1. Disconnect the Q13 harness connector.

   2. Disconnect the G24 amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Q13-8 (+) - G24-4 (TEC) Always Below 1 Ω Q13-7 (-) - G24-19 (SGND) Always Below 1 Ω Q13-8 (+) - Body ground Always 10 kΩ or higher Q13-7 (-) - Body ground Always 10 kΩ or higher

   
   

   OK

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR