DTC B1462/62: Room Humidity Sensor Circuit: Procedure

1. Remove the air conditioning amplifier with the connectors still connected. Refer to REMOVAL .
   Fig 1: Identifying Air Conditioning Amplifier

   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
   D37-28 (RH) - D37-35 (SG-4)	Ignition switch ON at 25°C (77°F)	1.8 to 2.2 V
   D37-28 (RH) - D37-35 (SG-4)	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 (When troubleshooting according to the PROBLEM SYMPTOMS TABLE)	B
   OK (When troubleshooting according to the DTC)	C

B → See step   5 

C → See step   6 

A: Go to next step 

1. Disconnect the D26 sensor connector.
   Fig 2: Identifying Harness And Connector (Room Temperature Sensor - Air Conditioning Amplifier Assembly)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D37 amplifier connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D37-28 (RH) - D26-3 (RH)	Always	Below 1 Ω
   D37-31 (S5-4) - D26-4 (S5)	Always	Below 1 Ω
   D37-35 (SG-4) - D26-2 (-)	Always	Below 1 Ω
   D37-28 (RH) - Body ground	Always	10 kΩ or higher
   D37-31 (S5-4) - Body ground	Always	10 kΩ or higher
   D37-35 (SG-4) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the D37 amplifier connector.
   Fig 3: Identifying Harness And Connector (Power Source Circuit)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   D26-4 (S5) - Body ground	Ignition switch ON	4.5 to 5.5 V

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

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D26-2 (-) - Body ground	Always	Below 1 Ω

NG → See step   6 

OK: Go to next step 

1. Remove the room temperature sensor with its connector still connected. Refer to REMOVAL .
   Fig 4: Identifying Room Temperature Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.
   Fig 5: Humidity And Voltage Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Condition	Specified Condition
   D26-3 (RH) - D26-2 (-)	Humidity 10% at 25°C (77°F)	0.7 to 1.08 V
   D26-3 (RH) - D26-2 (-)	Humidity 20% at 25°C (77°F)	0.72 to 1.57 V
   D26-3 (RH) - D26-2 (-)	Humidity 30% at 25°C (77°F)	1.13 to 1.95 V
   D26-3 (RH) - D26-2 (-)	Humidity 40% at 25°C (77°F)	1.61 to 2.24 V
   D26-3 (RH) - D26-2 (-)	Humidity 650% at 25°C (77°F)	1.99 to 2.46 V
   D26-3 (RH) - D26-2 (-)	Humidity 60% at 25°C (77°F)	2.26 to 2.66 V
   D26-3 (RH) - D26-2 (-)	Humidity 70% at 25°C (77°F)	2.48 to 2.85 V
   D26-3 (RH) - D26-2 (-)	Humidity 80% at 25°C (77°F)	2.68 to 3.04 V
   D26-3 (RH) - D26-2 (-)	Humidity 90% at 25°C (77°F)	2.87 to 3.05 V

   NOTE:

   • Touching the sensor even slightly may change the output voltage. Be sure to hold the connector of the sensor.
   • The output voltages shown above are at 25°C (77°F).

NG → See step   7 

OK → See step   6