LIN Communication Circuit: Procedure

1. Check the air conditioning system is functioning properly.

   Result

   Result	Proceed to
   Front air conditioning control malfunctions	A
   Rear air conditioning control malfunctions	B

B → See step   4 

A: Go to next step 

1. Disconnect the E10 control connector.
   Fig 1: Identifying Harness And Connector (Air Conditioning Control Assembly - Air Conditioning Amplifier)

   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
   D37-37 (LIN1) - E10-5 (LIN1)	Always	Below 1 Ω
   D37-37 (LIN1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   3 

1. Disconnect the R1 control connector.
   Fig 2: Identifying Harness And Connector (Rear Air Conditioning Control Assembly - Air Conditioning Amplifier)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D38 amplifier connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D38-13 (RLIN) - R1-5 (MPX-)	Always	Below 1 Ω
   D38-13 (RLIN) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   3