| Last Modified: 06-05-2026 | 6.11:8.1.0 | Doc ID: RM100000001H5W1 |
| Model Year Start: 2020 | Model: Corolla HV | Prod Date Range: [01/2019 - 09/2022] |
| Title: LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): Daytime Running Light Circuit; 2020 - 2022 MY 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 HV [01/2019 - 04/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)
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 Click here
|
|
|
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
OK:
Daytime running lights illuminate.
| OK |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here
|
|
|
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 |
|
|
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
(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 |
|
|
|
|