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.

The glass temperature sensor is integrated with the air conditioning thermistor assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM

   1. Connect the Techstream to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the Techstream on.

   4. Enter the following menus: Body Electrical / 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
      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

   B

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

   C

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   A

2. 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 S3-4 (TFG) - S3-1 (SEG3) 10°C (50°F) 5.92 to 6.09 kΩ S3-4 (TFG) - S3-1 (SEG3) 15°C (59°F) 4.94 to 5.07 kΩ S3-4 (TFG) - S3-1 (SEG3) 20°C (68°F) 4.20 to 4.29 kΩ S3-4 (TFG) - S3-1 (SEG3) 25°C (77°F) 3.64 to 3.70 kΩ S3-4 (TFG) - S3-1 (SEG3) 30°C (86°F) 3.19 to 3.26 kΩ S3-4 (TFG) - S3-1 (SEG3) 35°C (95°F) 2.85 to 2.91 kΩ S3-4 (TFG) - S3-1 (SEG3) 40°C (104°F) 2.58 to 2.64 kΩ S3-4 (TFG) - S3-1 (SEG3) 45°C (113°F) 2.37 to 2.43 kΩ S3-4 (TFG) - S3-1 (SEG3) 50°C (122°F) 2.21 to 2.26 kΩ S3-4 (TFG) - S3-1 (SEG3) 55°C (131°F) 2.07 to 2.12 kΩ S3-4 (TFG) - S3-1 (SEG3) 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.

      Text in Illustration

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

   NG

   REPLACE AIR CONDITIONING THERMISTOR ASSEMBLY Click here

   OK

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

   1. Disconnect the I77 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition S3-4 (TFG) - I77-6 (TFG) Always Below 1 Ω S3-4 (TFG) - Body ground Always 10 kΩ or higher S3-1 (SEG3) - I77-35 (SG-4) Always Below 1 Ω S3-1 (SEG3) - Body ground Always 10 kΩ or higher

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here