Wiper Signal Circuit: Procedure

WARNING: This page is about a different car, the 2012 Lexus GX 460. However, it is still accessible from the selected car via links, so may be relevant.

CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - WINDSHIELD WASHER SWITCH)

Disconnect the G43 driving support ECU connector.
Disconnect the G50 windshield wiper switch connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
G43-32 (WIP2) - G50-9 (+2)	Always	Below 1 Ω
G43-32 (WIP2) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK WINDSHIELD WIPER SWITCH ASSEMBLY

Remove the windshield wiper switch with its connector still connected. Refer to REMOVAL .

Fig 1: Identifying Windshield Wiper Switch Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Voltage

Tester Connection	Switch Condition	Specified Condition
G50-9 (+2) - Body ground	Engine switch on (IG), windshield wiper switch Hi	11 to 14 V
G50-9 (+2) - Body ground	Engine switch on (IG), windshield wiper switch Lo	Approximately 9 V
G50-9 (+2) - Body ground	Engine switch on (IG), windshield wiper switch off	Below 1 V

TEXT IN ILLUSTRATION

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

NG → See step 3

OK → See step 4

REPLACE WINDSHIELD WASHER SWITCH ASSEMBLY. Refer to REMOVAL
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE