Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001H5W1
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): Daytime Running Light Circuit; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

Daytime Running Light Circuit

DESCRIPTION

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

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

Click here 2020 MY Corolla Corolla HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION 2021 - 2022 MY Corolla Corolla HV [04/2020 - 09/2022]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION

PROCEDURE

1.

CHECK OPERATION (LOW BEAM HEADLIGHTS)

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

OK:

The low beam headlights operate normally.

NG

GO TO PROBLEM SYMPTOMS TABLE 2020 - 2021 MY Corolla Corolla HV [01/2019 - 06/2021]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE 2022 MY Corolla Corolla HV [06/2021 - 09/2022]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE

OK

2.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(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.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 2020 - 2021 MY Corolla Corolla HV [01/2019 - 06/2021]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE 2022 MY Corolla Corolla HV [06/2021 - 09/2022]; LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE

NG

3.

CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - HEADLIGHT ASSEMBLY)

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

(b) Disconnect the A81 headlight assembly LH connector.

(c) Disconnect the A80 headlight assembly RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4B-28 - A81-1 (B)

Always

Below 1 Ω

4B-28 - A80-1 (B)

Always

Below 1 Ω

4B-28 or A81-1 (B) - Body ground

Always

10 kΩ or higher

4B-28 or A80-1 (B) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

*a

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 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4B-28 - MB-25 (DRL)

Always

Below 1 Ω

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL