Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Daytime Running Light Circuit

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Exterior / Lighting (ext) / Lighting System(for Hv Model Without Cornering Light) / Daytime Running Light Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the daytime running lights.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.
Before replacing the main body ECU (multiplex network body ECU), refer to Registration.
Click here

PROCEDURE

1.	CHECK OPERATION (LOW BEAM HEADLIGHTS)

(a) Check the operation of the low beam headlights.

OK:

The low beam headlights operate normally.

GO TO PROBLEM SYMPTOMS TABLE

2.	PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(d) Enter the following menus: Body Electrical / Main Body / Active Test.

(e) 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	OFF or ON	-

Body Electrical > Main Body > Active Test

Tester Display
Daytime Running Light

OK:

Daytime running lights illuminate.

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

3.	INSPECT DRL RELAY

(a) Inspect the DRL relay.

Click here

REPLACE DRL RELAY

4.	CHECK HARNESS AND CONNECTOR (POWER SOURCE - DRL RELAY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
1 (DRL relay) - Body ground	Power switch off	11 to 14 V
3 (DRL relay) - Body ground	Power switch off	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	CHECK HARNESS AND CONNECTOR (DRL RELAY - HEADLIGHT ASSEMBLY)

(a) Disconnect the A45 headlight assembly LH connector.

(b) Disconnect the A44 headlight assembly RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
5 (DRL relay) - A45-1 (B)	Always	Below 1 Ω
5 (DRL relay) - A44-1 (B)	Always	Below 1 Ω
5 (DRL relay) or A45-1 (B) - Body ground	Always	10 kΩ or higher
5 (DRL relay) or A44-1 (B) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HARNESS AND CONNECTOR (DRL RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 4F instrument panel junction block assembly connector.

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

Standard Resistance:

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

Component without harness connected

(Instrument Panel Junction Block Assembly)

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

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
4F-28 - MB-25 (DRL)	Always	Below 1 Ω

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

See More:

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PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected ...

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Daytime Running Light Circuit

Data List / Active Test

Diagnostic Trouble Code Chart

See More:

Toyota Avalon (XX50) 2019-2022 Owners Manual

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual