Daytime Running Light Relay Circuit [11/2015 - 07/2020]: Procedure

1. Check the operation of the low beam headlights.

   OK

   The low beam headlights operate normally.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [11/2015 - 12/2018]  , or refer to  PROBLEM SYMPTOMS TABLE [12/2018 -] 

Result: 

OK 

See step  2

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. Perform the Active Test according to the display on the Techstream.

   Body Electrical > Main Body > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Daytime Running Light	Daytime running lights	ON or OFF	-

   Body Electrical > Main Body > Active Test 

   Tester Display
   Daytime Running Light

   OK

   Daytime running lights illuminate.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [11/2015 - 12/2018]  , or refer to  PROBLEM SYMPTOMS TABLE [12/2018 -] 

Result: 

NG 

See step  3

1. Disconnect the 3F instrument panel junction block assembly connector.
2. Disconnect A11*1 and A34*2 headlight assembly connector.
   1. *1: for LH side
   2. *2: for RH side
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   (A11, A34)

   (A11)

   (A34)

   Tester Connection	Condition	Specified Condition
   A11-6 (B) - 3F-28	Always	Below 1 Ω
   3F-28 or A11-6 (B) - Body ground	Always	10 kΩ or higher
   A34-6 (B) - 3F-28	Always	Below 1 Ω
   3F-28 or A34-6 (B) - Body ground	Always	10 kΩ or higher
   A11-1 (E) - Body ground	Always	Below 1 Ω
   A34-1 (E) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [11/2015 - 12/2018] , or refer to REMOVAL [12/2018 - 07/2020]

2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   -

   -

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3F-28 - MB-25 (DRL)	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [11/2015 - 12/2018]  , or refer to  REMOVAL [12/2018 - 07/2020] 

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [11/2015 - 12/2018]  , or refer to  REMOVAL [12/2018 - 07/2020]