AIR CONDITIONING SYSTEM, Diagnostic DTC:B14A8

DESCRIPTION

The air conditioning amplifier assembly detects the windshield glass surface temperature from this circuit. The air conditioning amplifier assembly applies voltage to the air conditioning thermistor assembly (glass temperature sensor). As the windshield glass surface temperature rises, the resistance decreases. The air conditioning amplifier assembly detects the resistance change as the windshield glass surface temperature changes.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   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.

      Table 1. Air Conditioner

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Glass Temperature	Glass temperature/ Min.: -327.68°C (-557.82°F) Max.: 327.67°C (621.81°F)	Actual glass 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

   
   
   • AClick here
   • BClick here
   • CClick here
2. Click here

   INSPECT AIR CONDITIONING THERMISTOR ASSEMBLY (GLASS TEMPERATURE SENSOR)

   
   
   1. 

      Remove the air conditioning thermistor assembly (glass temperature sensor) (Click here).

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

      Standard Resistance

      Tester Connection Condition Specified Condition T11-1 (SEG3) - T11-4 (TFG) 10°C (50°F) 5.92 to 6.09 kΩ T11-1 (SEG3) - T11-4 (TFG) 15°C (59°F) 4.94 to 5.07 kΩ T11-1 (SEG3) - T11-4 (TFG) 20°C (68°F) 4.20 to 4.29 kΩ T11-1 (SEG3) - T11-4 (TFG) 25°C (77°F) 3.64 to 3.70 kΩ T11-1 (SEG3) - T11-4 (TFG) 30°C (86°F) 3.19 to 3.26 kΩ T11-1 (SEG3) - T11-4 (TFG) 35°C (95°F) 2.85 to 2.91 kΩ T11-1 (SEG3) - T11-4 (TFG) 40°C (104°F) 2.58 to 2.64 kΩ T11-1 (SEG3) - T11-4 (TFG) 45°C (113°F) 2.37 to 2.43 kΩ T11-1 (SEG3) - T11-4 (TFG) 50°C (122°F) 2.21 to 2.26 kΩ T11-1 (SEG3) - T11-4 (TFG) 55°C (131°F) 2.07 to 2.12 kΩ T11-1 (SEG3) - T11-4 (TFG) 60°C (140°F) 1.97 to 2.01 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.

      Table 2. Text in Illustration

      *a	Heat Conduction Sheet Part
      *b	Component without harness connected (Air Conditioning Thermistor Assembly (Glass Temperature Sensor))
      *c	Resistance (kΩ)
      *d	Temperature (°C (°F))

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - GLASS TEMPERATURE SENSOR)

   
   

   1. Disconnect the T11 air conditioning thermistor assembly (glass temperature sensor) connector.

   2. Disconnect the H86 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition T11-4 (TFG) - H86-15 (TFG) Always Below 1 Ω T11-4 (TFG) - Body ground Always 10 kΩ or higher T11-1 (SEG3) - H86-7 (LBLO) Always Below 1 Ω T11-1 (SEG3) - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NGClick here
4. Click here

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLYClick here

5. Click here

   REPLACE AIR CONDITIONING THERMISTOR ASSEMBLYClick here

6. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR

7. Click here

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here