DTC B14AA: Glass Humidity Sensor Circuit [10/2014 - ]: Procedure

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 Humidity	Glass humidity / Min.: 0.00%, Max.: 100.00%	Actual glass humidity displayed	-

   OK

   The display is as specified in the normal condition column.

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

See step  2

1. Disconnect the N3 air conditioning thermistor assembly (glass humidity sensor) connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   N3-5 (S5V) - Body ground	Power switch on (IG)	4.5 to 5.5 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Air Conditioning Thermistor Assembly (Glass Humidity Sensor))

Result: 

NG 

See step  5

Result: 

OK 

See step  3

1. Remove the air conditioning thermistor assembly (glass humidity sensor) with the connector still connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   1 (SEG3) - 3 (RH)	Humidity is 5 to 15%	1.01 V
   1 (SEG3) - 3 (RH)	Humidity is 15 to 25%	1.37 V
   1 (SEG3) - 3 (RH)	Humidity is 25 to 35%	1.73 V
   1 (SEG3) - 3 (RH)	Humidity is 35 to 45%	2.09 V
   1 (SEG3) - 3 (RH)	Humidity is 45 to 55%	2.45 V
   1 (SEG3) - 3 (RH)	Humidity is 55 to 65%	2.81 V
   1 (SEG3) - 3 (RH)	Humidity is 65 to 75%	3.17 V
   1 (SEG3) - 3 (RH)	Humidity is 75 to 85%	3.53 V
   1 (SEG3) - 3 (RH)	Humidity is 85 to 95%	3.89 V

   NOTE:

   • Do not touch the sensor as body heat will affect the inspection results. When performing the inspection, hold the sensor by its connector.
   • Allow the sensor to acclimate to the ambient temperature and humidity before performing the inspection.
   • The specified voltages in the table above are based on inspections performed when the ambient temperature is 25°C (77°F).

   HINT: 

   As the humidity increases, the voltage increases (see the graph).

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Air Conditioning Thermistor Assembly (Glass Humidity Sensor))
   *b	Heat Conduction Sheet Part
   *c	Voltage (V)
   *d	Relative Humidity (%)

Result: 

NG 

REPLACE AIR CONDITIONING THERMISTOR ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

OK 

See step  4

1. Disconnect the N3 air conditioning thermistor assembly (glass humidity sensor) connector.
2. Disconnect the D62 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
   N3-3 (RH) - D62-28 (RH)	Always	Below 1 Ω
   N3-3 (RH) - Body ground	Always	10 kΩ or higher
   N3-1 (SEG3) - D62-35 (SG-4)	Always	Below 1 Ω
   N3-1 (SEG3) - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the D62 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
   N3-5 (S5V) - D62-31 (S5-4)	Always	Below 1 Ω
   N3-5 (S5V) - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR