AIR CONDITIONING SYSTEM, Diagnostic DTC:B1413/13

DESCRIPTION

The evaporator temperature sensor is installed on the evaporator in the air conditioning unit to detect the cooled air temperature that has passed through the evaporator and to control the air conditioning. It sends appropriate signals to the A/C amplifier. The resistance of the 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 A/C amplifier applies voltage (5 V) to the evaporator temperature sensor and reads voltage changes as the resistance of the evaporator temperature sensor changes. This sensor is used for frost prevention.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the intelligent tester on.

   4. Enter the following menus: Body / Air Conditioner / Data List.

   5. Check the value(s) by referring to the table below.

      Air Conditioner

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Evaporator Fin Thermistor	Evaporator temperature sensor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F)	Actual evaporator temperature displayed	-

      OK
      The display is as specified in the Normal Condition column.

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

   
   

   B

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

   C

   REPLACE A/C AMPLIFIER Click here

   A

2. INSPECT EVAPORATOR TEMPERATURE SENSOR

   
   

   1. Remove the evaporator temperature sensor.

   2. 

      Text in Illustration

      *1	Component without harness connected (Evaporator Temperature Sensor)
      *2	Sensing Portion

      Disconnect the evaporator temperature sensor connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition z40-1 - z40-2 -10°C (14°F) 7.30 to 9.10 kΩ z40-1 - z40-2 -5°C (23°F) 5.65 to 6.95 kΩ z40-1 - z40-2 0°C (32°F) 4.40 to 5.35 kΩ z40-1 - z40-2 5°C (41°F) 3.40 to 4.15 kΩ z40-1 - z40-2 10°C (50°F) 2.70 to 3.25 kΩ z40-1 - z40-2 15°C (59°F) 2.14 to 2.58 kΩ z40-1 - z40-2 20°C (68°F) 1.71 to 2.05 kΩ z40-1 - z40-2 25°C (77°F) 1.38 to 1.64 kΩ z40-1 - z40-2 30°C (86°F) 1.11 to 1.32 kΩ

      Note

      
      

      • Hold the sensor only by its connector. Touching the sensor may change the resistance value.

      • 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 EVAPORATOR TEMPERATURE SENSOR Click here

   OK

3. INSPECT AIR CONDITIONING HARNESS (A/C AMPLIFIER - EVAPORATOR TEMPERATURE SENSOR)

   
   

   1. 

      Remove the air conditioning harness.

   2. 

      Text in Illustration

      *1	Front view of wire harness connector (to A/C Amplifier)
      *2	Front view of wire harness connector (to Evaporator Temperature Sensor)

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

      Standard Resistance
      Tester Connection Condition Specified Condition z6-6 (TE) - z40-2 Always Below 1 Ω z6-5 (SG) - z40-1 Always Below 1 Ω z6-6 (TE) - Body ground Always 10 kΩ or higher z6-5 (SG) - Body ground Always 10 kΩ or higher

   
   

   NG

   REPLACE AIR CONDITIONING HARNESS Click here

   OK

   REPLACE A/C AMPLIFIER Click here