Rain Drop Sensing Function Does Not Operate: Wiring Diagram

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Rain Drop Sensing Wiring Diagram

CHECK WINDSHIELD WIPER SWITCH ASSY
1. Check the continuity between terminals as shown in the chart below.
  Standard:
  
  Fig 2: Checking Continuity Between Terminals Specific Condition Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE WINDSHIELD WIPER SWITCH ASSY

OK: Go to next step.
CHECK HARNESS AND CONNECTOR
1. Check the continuity between terminals of windshield wiper switch and windshield wiper relay assy as shown in the chart below.
  Standard:
  
  Fig 3: Windshield Wiper Switch To Windshield Wiper Relay Continuity Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step.
CHECK HARNESS AND CONNECTOR
1. Check the continuity between terminals of windshield wiper relay assy and rain sensor as shown in the chart below.
  Standard:
  
  Fig 4: Windshield Wiper Relay Assy To Rain Sensor Continuity Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step.
CHECK RAIN SENSOR
1. Disconnect the connector of the rain sensor.
2. Measure voltage between terminal 1 (SIG) and body ground.
  Standard: 8V
NG: REPLACE WINDSHIELD WIPER RELAY ASSY

OK: Go to next step.
CHECK RAIN SENSOR
1. Check the continuity between terminal 4 (ES) of rain sensor and body ground.
  Standard: There is continuity.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step.
CHECK RAIN SENSOR
1. Using an oscilloscope, check that signal waveform appears between terminal 3 (WIP) and body ground as shown in the illustration.
  Standard: Bar appears.
  
  Fig 5: Identifying Rain Sensor Signal Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
A: --> Wiper SW: AUTO,

Wiper position: Positions except stop position

B: --> Wiper SW: AUTO,

Wiper position: Stop position

NG: REPLACE WINDSHIELD WIPER RELAY ASSY

OK: Go to next step.
CHECK RAIN SENSOR(BETWEEN RAIN SENSOR AND BODY GROUND)
1. Check that voltage between 2 (AUTO) and body ground follows the standard value as shown in the chart below.
  Standard:
  
  Fig 6: Checking Voltage Between Rain Sensor & Body Ground Results Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPLACE RAIN SENSOR

OK: REPLACE WINDSHIELD WIPER RELAY ASSY