Taillight Relay Circuit [10/2014 - ]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Active Test.
5. Check that the relay operates.
   MAIN BODY
   
   

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

   OK

   Taillight relay operates (Taillights illuminate).

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

(Refer to PROBLEM SYMPTOMS TABLE [10/2014 - 10/2015] or PROBLEM SYMPTOMS TABLE [10/2015 - ] )

Result: 

NG 

See step  2

1. Disconnect the 3E instrument panel junction block assembly connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   3E-1 - Body ground	Power switch off	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

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 - 10/2015] or REMOVAL [10/2015 - ] ).
2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   -

   -

3. Connect a positive (+) lead from the auxiliary battery to terminal 3E-1.
4. Connect a negative (-) lead from the auxiliary battery to terminal MB-14 (TRLY).
5. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   3D-3 - Auxiliary battery negative terminal	Power switch off	11 to 14 V
   3D-6 - Auxiliary battery negative terminal	Power switch off	11 to 14 V
   3D-7 - Auxiliary battery negative terminal	Power switch off	11 to 14 V
   3D-8 - Auxiliary battery negative terminal	Power switch off	11 to 14 V
   3C-4 - Auxiliary battery negative terminal	Power switch off	11 to 14 V

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 

(Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] )

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

(Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] )