Taillight Relay Circuit [10/2014 - 09/2017]: Procedure

1. Using the Techstream, perform the Active Test.

   Refer to DATA LIST / ACTIVE TEST [10/2014 - 09/2017]

   Body Electrical > Main Body > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Taillight Relay	Taillight relay	ON or OFF	-

   Body Electrical > Main Body > Active Test 

   Tester Display
   Taillight Relay

   Result

   Result	Proceed to
   Taillights, license lights and side marker lights come on	A
   Taillights, license lights and side marker lights do not come on	B

Result: 

A 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [10/2014 - 09/2017] 

Result: 

B 

See step  2

1. Disconnect the instrument panel junction block assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   4F-1 - Body ground	Always	11 to 14 V

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Instrument Panel Junction Block Assembly)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [10/2014 - 05/2019]

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [10/2014 - 05/2019]

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   4A-37 - Battery negative (-) terminal	Battery voltage applied between terminals 4F-1 and A-14 (TRLY)	11 to 14 V
   	Battery voltage not applied between terminals 4F-1 and A-14 (TRLY)	Below 1 V
   4A-38 - Battery negative (-) terminal	Battery voltage applied between terminals 4F-1 and A-14 (TRLY)	11 to 14 V
   	Battery voltage not applied between terminals 4F-1 and A-14 (TRLY)	Below 1 V

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2014 - 05/2019] 

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [10/2014 - 05/2019]