RX400h · Service Manual HEATER & AIR CONDITIONING SYSTEM

B1462/62

Diagnostic trouble codes

DESCRIPTION

The A/C room humidity sensor detects cabin humidity. The voltage of the A/C room temperature sensor changes in accordance with cabin humidity. The A/C amplifier assembly reads changes in the A/C room humidity sensor.
The A/C room humidity sensor is integrated with the A/C room temperature sensor.
DTC No.
 DTC Detecting Condition
 Trouble Area
B1462/62
 Open or short in room humidity sensor circuit
  1. A/C room humidity sensor (A/C room temperature sensor)
  2. Harness or connector between A/C room humidity sensor (A/C room temperature sensor) and A/C amplifier assembly
  3. A/C amplifier assembly

WIRING DIAGRAM

E108928E06

INSPECTION PROCEDURE


1. READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON 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.

DATA LIST / AIR CONDITIONER 
Item
 Measurement Item/Display
(Range)
 Normal Condition
 Diagnostic Note
HUMIDITY SENS
 Humidity sensor / min.: 0% max.: 100%
 Actual cabin humidity is displayed
 -

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


Result:
Result
 Proceed to
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 ASSEMBLY
A


2. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

  1. E109265E28
    Remove the A/C amplifier assembly with the connectors still connected.

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

    Voltage:
    Tester connection
    (Symbols)
    		 Condition
    		 Specified condition
    A11-22 (RH) - A11-24 (SSR+)
    		 Ignition switch ON
    at 25°C (77°F)
    		 1.8 to 2.2 V
    A11-22 (RH) - A11-24 (SSR+)
    		 Ignition switch ON
    at 40°C (104°F)
    		 1.2 to 1.6 V

HINT:
As the temperature increases, the voltage decreases.


Result:
Result
 Proceed to
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 ASSEMBLY
A


3. INSPECT A/C ROOM TEMPERATURE SENSOR

  1. E108929E09
    Remove the A/C room temperature sensor.

  1. Turn the ignition switch ON.

  1. E109268E01
    Measure the voltage according to the value(s) in the table below.

    Voltage:
    Tester connection
    (Symbols)
    		 Condition
    		 Specified condition
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 10%
    		 0.7 to 1.08 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 20%
    		 0.72 to 1.57 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 30%
    		 1.13 to 1.95 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 40%
    		 1.61 to 2.24 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 50%
    		 1.99 to 2.46 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 60%
    		 2.26 to 2.66 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 70%
    		 2.48 to 2.85 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 80%
    		 2.68 to 3.04 V
    A33-3 (S5) - A33-4 (VO)
    		 at 25°C (77°F)
    Humidity 90%
    		 2.87 to 3.05 V

    NOTICE:
    1. Do not touch the A/C room humidity sensor because it may be affected by body temperature and may not work properly.
    2. Be sure to hold the connector of the sensor.
    3. The output voltage at the ambient temperature 25°C (77°F) is shown above.



 NG
REPLACE A/C ROOM TEMPERATURE SENSOR
OK


4. CHECK HARNESS AND CONNECTOR (A/C ROOM TEMPERATURE SENSOR - A/C AMPLIFIER ASSEMBLY)

  1. E108939E06
    Disconnect the connector from the A/C amplifier assembly.

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

    Resistance:
    Tester connection
    (Symbols)
    		 Condition
    		 Specified condition
    A11-24 (SSR+) - A33-3 (S5)
    		 Always
    		 Below 1 Ω
    A11-22 (RH) - A33-4 (VO)
    		 Always
    		 Below 1 Ω
    A11-3 (SSR+) - Body ground
    		 Always
    		 10 kΩ or higher
    A11-22 (RH) - Body ground
    		 Always
    		 10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY


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