Taillight Relay Circuit: Procedure

PERFORM ACTIVE TEST USING TECHSTREAM (TAILLIGHT RELAY)

Using the Techstream, perform the Active Test. Refer to DATA LIST / ACTIVE TEST .

MAIN BODY

Tester Display	Test Part	Control Range	Diagnostic Note
Taillight Relay	Taillight relay	ON/OFF	-

Taillight relay operates (taillights illuminate).

NG → See step 2

OK → See step 4

CHECK HARNESS AND CONNECTOR (BATTERY - MAIN BODY ECU)

Remove the main body ECU. Refer to REMOVAL .

Fig 1: Identifying Harness And Connector (Battery - Main Body ECU)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Voltage

Tester Connection	Condition	Specified Condition
A-14 (TRLY) - Body ground	Always	11 to 14 V

TEXT IN ILLUSTRATION

*a	Front view of wire harness connector (to Main Body ECU)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 3

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL