Inspection Procedure

1. Connect the intelligent tester (with CAN VIM) to DLC3.
2. Turn the power switch ON (IG) and push the intelligent tester main switch ON.
3. Select the item below in the DATA LIST, and read the display on the intelligent tester.

   Air conditioning amplifier 

   DATA LIST
   
   

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

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

   Result 

   RESULT REFERENCE
   
   

   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 

A : Go to next step 

1. Remove the air conditioning amplifier with connectors still connected.
2. Measure the voltage of the wire harness side connector.

   Standard voltage 

   TERMINALS VOLTAGE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   A7-9 (RH) - A7-10 (S5RM)	Power switch ON (IG) at 25°C (77°F)	1.8 to 2.2 V
   A7-9 (RH) - A7-10 (S5RM)	Power switch ON (IG) at 40°C (104°F)	1.2 to 1.6 V

   HINT:

   As the temperature increases, the voltage decreases.

   Result 

   RESULT REFERENCE
   
   

   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 

Fig 1: Identifying Air Conditioning Amplifier Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

A : Go to next step 

1. Remove the room temperature sensor.
2. Measure the voltage of the sensor.

   Standard voltage: at 25°C (77°F) Humidity 40%: 1.61 to 2.24 V 

   at 25°C (77°F) Humidity 60%: 2.26 to 2.66 V 

   HINT:

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

NG : REPLACE ROOM TEMPERATURE SENSOR 

Fig 2: Room Temperature Sensor Voltage Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Disconnect the A9 sensor connector.
2. Disconnect the A7 amplifier connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Specified Condition
   A7-9 (RH) - A9-3 (VO)	Below 1 Ω
   A7-10 (S5RM) - A9-4 (S5)	Below 1 Ω
   A7-9 (RH) - Body ground	10 kΩ or higher
   A7-10 (S5RM) - Body ground	10 kΩ or higher

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

Fig 3: Disconnecting A7 Amplifier Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : REPLACE AIR CONDITIONING AMPLIFIER