Wiper and Washer Switch Circuit: Procedure

1. Remove the windshield wiper switch assembly. Refer to REMOVAL .
2. Measure the resistance according to the value(s) in the table below.
   Fig 1: Identifying H27 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Front Washer Switch 

   Adjusting Ring*1 

   FRONT WIPER SWITCH
   
   

   Tester Connection	Switch Condition	Specified Condition
   H27-3 (+1) - H27-1 (+S)	OFF	Below 1 Ω
   H27-3 (+1) - H27-2 (+B)	MIST
   	LO
   H27-2 (+B) - H27-4 (+2)	HI
   H27-9 (AUTO) - H27-10 (E)	AUTO*1

   Tester Connection	Switch Condition	Specified Condition
   H28-2 (EW) - H28-3 (WF)	ON	Below 1 Ω
   	OFF	10 kΩ or higher

   Tester Connection	Condition	Specified Condition
   H27-7 (VR1) - H27-8 (VR2)	Adjusting ring changed from (+) side to (-) side	0 to 2.7 kΩ

   • *1: w/ Rain Sensor
   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Windshield Wiper Switch Assembly)

NG → See step   3 

OK: Go to next step 

1. Disconnect the H28 and H27 windshield wiper switch assembly connectors.
2. Disconnect the H75 windshield wiper relay assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H27-2 (+B) - H75-12 (IG)	Always	Below 1 Ω
   H27-2 (+B) - Body ground	Always	10 kΩ or higher
   H27-3 (+1) - H75-1 (+2S)	Always	Below 1 Ω
   H27-3 (+1) - Body ground	Always	10 kΩ or higher
   H27-4 (+2) - H75-3 (+2)	Always	Below 1 Ω
   H27-4 (+2) - Body ground	Always	10 kΩ or higher
   H27-1 (+S) - H75-11 (+SSW)	Always	Below 1 Ω
   H27-1 (+S) - Body ground	Always	10 kΩ or higher
   H27-9 (AUTO)*1 - H75-17 (C1)	Always	Below 1 Ω
   H27-9 (AUTO)*1 - Body ground	Always	10 kΩ or higher
   H27-10 (E) - H75-16 (CO)	Always	Below 1 Ω
   H27-10 (E) - Body ground	Always	10 kΩ or higher
   H27-7 (VR1)*1 - H75-7 (VR1)	Always	Below 1 Ω
   H27-7 (VR1)*1 - Body ground	Always	10 kΩ or higher
   H27-8 (VR2)*1 - H75-6 (VR2)	Always	Below 1 Ω
   H27-8 (VR2)*1 - Body ground	Always	10 kΩ or higher
   H28-3 (WF) - H75-4 (W)	Always	Below 1 Ω
   H28-3 (WF) - Body ground	Always	10 kΩ or higher
   H28-2 (EW) - Body ground	Always	Below 1 Ω

   • *1: w/ Rain Sensor

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   4