Rain Sensor Circuit: Procedure

1. Disconnect the H75 windshield wiper relay assembly connector.
2. Disconnect the T7 rain sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H75-8 (SIG) - T7-4 (SIG)	Always	Below 1 Ω
   T7-4 (SIG) - Body ground	Always	10 kΩ or higher
   H75-14 (PA1) - T7-3 (AUTO)	Always	Below 1 Ω
   T7-3 (AUTO) - Body ground	Always	10 kΩ or higher
   H75-25 (E) - T7-1 (ES)	Always	Below 1 Ω
   T7-1 (ES) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the H75 windshield wiper relay assembly connector.
   Fig 1: Identifying H75 Connector Terminals

   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
   H75-8 (SIG) - H75-25 (E)	Power switch on (IG)	7.5 to 8.5 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Windshield Wiper Relay Assembly)

NG → See step   6 

OK: Go to next step 

1. Reconnect the T7 rain sensor connector.
   Fig 2: Identifying T7 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect an oscilloscope to the rain sensor connector.
3. Check for pulses.

   OK

   Tester Connection	Condition	Specified Condition
   T7-3 (AUTO) - T7-1 (ES)	Power switch on (IG)	Pulse generation

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Rain Sensor)

NG → See step   5 

OK → See step   4