Section 274 (Rain Sensor System - Diagnosis): Pre-Check

WARNING: This page is about a different car, the 2004 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.

DIAGNOSIS SYSTEM
1. Description
  ECU data of this system can be read from DLC3 of the vehicle.
  
  Therefore, when there seems to be a trouble on this system, use hand-held tester to check and troubleshoot it.
  
  Fig 1: Connecting Hand-Held Tester To DLC3
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the DLC3.
  The vehicle's ECM uses ISO 9141 -2 for communication.
  
  The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.
  
  Fig 2: Identifying DLC3 Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 3: DLC3 Terminals Reference Table
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  HINT:
  
  If your display shows "UNABLE TO CONNECT TO VEHICLE" when the cable of the hand- held tester is connected to DLC3, the ignition switch is turned ON and the hand- held tester is operated, there is a problem either on the vehicle side or tool side.
  - If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle.
  - If communication does not function when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.
DATA LIST
HINT:

By the DATA LIST displayed on the Hand-held tester, you can read the value of the switch, sensor, actuator and so on without removing parts. Reading the DATA LIST as a first step of troubleshooting is one of the method to shorten the labor time.
1. Turn the ignition switch OFF.
2. Connect the hand-held tester to DLC3.
3. Turn the ignition switch ON.
4. According to the display on tester, read the "DATA LIST".
Rain Sensor

Fig 4: Data List (Rain Sensor)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Wiper Control ECU

Fig 5: Data List (Wiper Control ECU)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
ACTIVE TEST
HINT:

Performing ACTIVE TEST using the Hand-held tester allows the relay, and so on to operate without removing any parts. Performing the ACTIVE TEST as a first step of troubleshooting is one of the method to shorten the labor time.

DATA LIST can be displayed during the ACTIVE TEST.
1. Turn the ignition switch OFF.
2. Connect the Hand-held tester to the DLC3.
3. Turn the ignition switch ON.
4. According to the display on tester, perform the "ACTIVE TEST".
Wiper Control ECU

Fig 6: Active Test Chart (Wiper Control ECU)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002