AIR CONDITIONING SYSTEM(for Manual Air Conditioning System), Diagnostic DTC:B1413/13

DESCRIPTION

The No. 1 cooler thermistor (evaporator temperature sensor) is installed on the evaporator in the air conditioner unit to detect the cooled air temperature that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the air conditioning amplifier assembly. The resistance of the No. 1 cooler thermistor (evaporator temperature sensor) changes in accordance with the cooled air temperature that has passed through the evaporator. 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 No. 1 cooler thermistor (evaporator temperature sensor) and reads voltage changes as the resistance of the No. 1 cooler thermistor (evaporator temperature sensor) changes. This sensor is used for frost prevention.

PROCEDURE

1. Click here

   READ VALUE USING GTS (EVAPORATOR FIN THERMISTOR)

   
   

   1. Use the Data List to check if the No. 1 cooler thermistor (evaporator temperature sensor) is functioning properly (Click here)

      Table 2. Air Conditioner

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Evaporator Fin Thermistor	No. 1 cooler thermistor / Min.: -29.7°C (-21.46°F), Max.: 59.55°C (139.19°F)	Actual evaporator temperature displayed	No. 1 cooler thermistor (evaporator temperature sensor) system malfunction: 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.

      Table 3. Result

      Result	Proceed to
      OK (When troubleshooting according to the DTC)	A
      OK (When troubleshooting according to Problem Symptoms Table)	B
      NG	C

   
   
   • A

     REPLACE AIR CONDITIONING HARNESS ASSEMBLY (Click here)

   • B

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

   • CClick here
2. Click here

   INSPECT NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR)

   
   

   1. Remove the No. 1 cooler thermistor (evaporator temperature sensor).

      
      

      • for LHD:Click here

      • for RHD:Click here

   2. Inspect the No. 1 cooler thermistor (evaporator temperature sensor).

      
      

      • for LHD:Click here

      • for RHD:Click here

      Table 4. Result

      Result	Proceed to
      OK	A
      NG (for LHD)	B
      NG (for RHD)	C

   
   
   • AClick here
   • B

     REPLACE NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR) (Click here)

   • C

     REPLACE NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR) (Click here)

3. Click here

   CHECK AIR CONDITIONING HARNESS ASSEMBLY

   
   
   1. 

      Remove the air conditioning harness assembly.

      
      

      • for LHD:Click here

      • for RHD:Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1 - z71-5 (SG) Always Below 1 Ω 2 - z71-6 (TE) Always Below 1 Ω 1 - 2 Always 10 kΩ or higher 1 or z71-5 (SG) - Body ground Always 10 kΩ or higher 2 or z71-6 (TE) - Body ground Always 10 kΩ or higher

      Table 5. Text in Illustration

      *a	Air Conditioning Harness Assembly
      *b	to No. 1 Cooler Thermistor (Evaporator Temperature Sensor) Connector
      *c	Front view of air conditioning harness assembly (to No. 1 Cooler Thermistor [Evaporator Temperature Sensor])
      *d	Front view of air conditioning harness assembly (to Air Conditioning Amplifier Assembly)

      Table 6. Result

      Result	Proceed to
      OK	A
      NG (for LHD)	B
      NG (for RHD)	C

   
   
   • A

     REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)

   • B

     REPLACE AIR CONDITIONING HARNESS ASSEMBLY (Click here)

   • C

     REPLACE AIR CONDITIONING HARNESS ASSEMBLY (Click here)