DTC    B1462/62    Room Humidity Sensor Circuit

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DESCRIPTION

The room humidity sensor detects room humidity. The voltage of the room humidity sensor changes in accordance with room humidity. The A/C amplifier reads changes in the room humidity sensor.
The room humidity sensor is integrated with the room temperature sensor.

DTC No.
DTC Detection Condition
Trouble Area
B1462/62
Open or short in room humidity sensor circuit
  1. Room humidity sensor (room temperature sensor)
  2. Harness and connector between room humidity sensor (room temperature sensor) and A/C amplifier
  3. A/C amplifier

WIRING DIAGRAM


E108199E01


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and push the intelligent tester main switch on.

  1. Select the item below in the Data List, and read the display on the intelligent tester.


A/C amplifier: 
Item
Measurement Item / Display
(Range)
Normal Condition
Diagnostic Note
Humidity Sensor
(Humidity Sens)
Humidity Sensor /
Min.: 0%, Max.: 100%
Actual room humidity is displayed
-

OK:
The display is as specified in the normal condition.


Result: 
NG
A
OK (Checking from the PROBLEM SYMPTOMS TABLE)
B
OK (Checking from the DTC)
C


B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER
A


2.CHECK WIRE HARNESS (ROOM TEMPERATURE SENSOR - A/C AMPLIFIER)
E106868E04

  1. Disconnect the L33 room temperature sensor connector.

  1. Disconnect the L52 A/C amplifier connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    L33-3 (RH) - L52-15 (RH)
    		Always
    		Below 1 Ω
    L33-4 (S5) - L52-7 (S5-1)
    		Always
    		Below 1 Ω
    L33-2 (-) - L52-19 (SG-1)
    		Always
    		Below 1 Ω
    L52-19 (SG-1) - Body ground
    		Always
    		10 kΩ or higher
    L52-15 (RH) - Body ground
    		Always
    		Below 1 Ω
    L52-7 (S5-1) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK AIR CONDITIONING AMPLIFIER
E107325E08

  1. Remove the A/C amplifier with its connectors still connected.

  1. Measure the voltage of the connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    L52-7 (S5-1) - L52-19 (SG-1)
    		Engine switch on (IG)
    		4.5 to 5.5 V



NG
REPLACE AIR CONDITIONING AMPLIFIER
OK


4.CHECK ROOM HUMIDITY SENSOR
E107329E03

  1. Remove the room temperature sensor.

  1. Measure the voltage of the sensor.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    2 (-) - 3 (RH)
    		10%
    		0.70 to 1.08 V
    2 (-) - 3 (RH)
    		20%
    		0.72 to 1.57 V
    2 (-) - 3 (RH)
    		30%
    		1.13 to 1.95 V
    2 (-) - 3 (RH)
    		40%
    		1.61 to 2.24 V
    2 (-) - 3 (RH)
    		50%
    		1.99 to 2.46 V
    2 (-) - 3 (RH)
    		60%
    		2.26 to 2.66 V
    2 (-) - 3 (RH)
    		70%
    		2.48 to 2.85 V
    2 (-) - 3 (RH)
    		80%
    		2.68 to 3.04 V
    2 (-) - 3 (RH)
    		90%
    		2.87 to 3.05 V

    NOTICE:
    1. Do not touch the humidity sensor as body heat will affect the inspection results. When performing the inspection, hold the sensor by its connector.
    2. Allow the sensor to acclimate to the ambient temperature and humidity before performing the inspection.
    3. The standard 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 resistance decreases (see the graph).



NG
REPLACE ROOM HUMIDITY SENSOR
OK

REPLACE AIR CONDITIONING AMPLIFIER