Daytime Running Light Circuit [12/2019 - 09/2020]: Procedure

1. Check the operation of the parking lights.

   OK

   The parking lights operate normally.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 09/2020] 

Result: 

OK 

See step  2

1. Perform the Active Test according to the display on the GTS.

   Body Electrical > Main Body > Active Test 

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

   Body Electrical > Main Body > Active Test 

   Tester Display
   Daytime Running Light

   OK

   Daytime running lights illuminate.

   Result

   Result	Proceed to
   OK	A
   NG (w/ Projector Headlight)	B
   NG (w/o Projector Headlight)	C

Result: 

A 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 09/2020] 

Result: 

C 

See step  7

Result: 

B 

See step  3

Refer to ON-VEHICLE INSPECTION [12/2019 - ]

Result

Result: 

NG 

REPLACE DRL RELAY 

Result: 

OK 

See step  4

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   2 (DRL relay) - Body ground	Ignition switch off*1 Always*2	11 to 14 V
   5 (DRL relay) - Body ground	Ignition switch off*1 Always*2	11 to 14 V

   1. *1: for HV Model
   2. *2: for Gasoline Model

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Disconnect the A66 headlight assembly LH connector.
2. Disconnect the A65 headlight assembly RH connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 (DRL relay) - A66-3 (B)	Always	Below 1 Ω
   3 (DRL relay) - A65-3 (B)	Always	Below 1 Ω
   3 (DRL relay) or A66-3 (B) - Body ground	Always	10 kΩ or higher
   3 (DRL relay) or A65-3 (B) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  6

1. Disconnect the 4C instrument panel junction block assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 (DRL relay) - 4C-28	Always	Below 1 Ω
   1 (DRL relay) or 4C-28 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  8

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the A66 headlight assembly LH connector.
2. Disconnect the A65 headlight assembly RH connector.
3. Disconnect the 4C instrument panel junction block assembly connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A66-3 (B) - 4C-28	Always	Below 1 Ω
   A65-3 (B) - 4C-28	Always	Below 1 Ω
   A66-3 (B) or 4C-28 - Body ground	Always	10 kΩ or higher
   A65-3 (B) or 4C-28 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  8

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

   Refer to REMOVAL [12/2019 - 10/2022]

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4C-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 [12/2019 - 10/2022] 

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]