Inspection Procedure

NOTE: When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.

READ VALUE OF TECHSTREAM (LIN COMMUNICATION)

Using the Techstream, read the "Data List".

Body No.5:

BODY NO.5 - DATA LIST TABLE

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
LIN Communication	Status of LIN communication / Without or With	Without: No connection With: Connection	-
Curr Comm Rain Sensor	Current communication with rain sensor / OK or Stop	OK: Connection Stop: No connection	-

OK: Techstream displays "With" and "OK".

NG: Go to step 2

OK: USE SIMULATION METHOD TO CHECK (See HOW TO PROCEED WITH TROUBLESHOOTING )

CHECK HARNESS AND CONNECTOR (FRONT LIGHT ECU - RAIN SENSOR)

Fig 1: Identifying Terminals Of A50 ECU & X8 Sensor Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Disconnect the A50 ECU connector.
Disconnect the X8 sensor connector.
Measure the resistance and voltage according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
A50-9 (LIN) - X8-3 (MPX)	Always	Below 1 Ω
A50-9 (LIN) or X8-3 (MPX) - Body ground	Always	10 kΩ or higher

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
A50-9 (LIN) or X8-3 (MPX) - Body ground	Always	Below 1 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: CHECK RAIN SENSOR (BATTERY VOLTAGE AND GROUND)

CHECK RAIN SENSOR (BATTERY VOLTAGE AND GROUND)

Disconnect the X8 sensor connector.
Measure the resistance and voltage according to the value(s) in the table below.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Condition	Specified Condition
X8-1 (ES) - Body ground	Always	Below 1 Ω

Fig 2: Identifying Terminals Of X8 Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard voltage

TESTER CONNECTION SPECIFIED CONDITION TABLE

Tester Connection	Switch Condition	Specified Condition
X8-4 (SIG) - Body ground	Engine Switch off	Below 1 V
X8-4 (SIG) - Body ground	Engine Switch on (IG)	11 to 14 V

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

REPLACE RAIN SENSOR
1. Temporarily replace the rain sensor with a new or normally functioning one (see RAIN SENSOR ).

READ VALUE OF TECHSTREAM (LIN COMMUNICATION)

Using the Techstream, read the "Data List".

Body No.5:

BODY NO.5 - DATA LIST TABLE

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
LIN Communication	Status of LIN communication / Without or With	Without: No connection With: Connection	-
Curr Comm Rain Sensor	Current communication with rain sensor / OK or Stop	OK: Connection Stop: No connection	-

OK: Techstream displays "With" and "OK".

NG: REPLACE FRONT LIGHT ECU (FRONT CONTROLLER)

OK: END (RAIN SENSOR IS DEFECTIVE)