| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001I0WS |
| Model Year Start: 2020 | Model: GR Corolla | Prod Date Range: [03/2019 - 09/2022] |
| Title: LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model without AFS): LO-beam Headlight does not Illuminate; 2020 - 2022 MY Corolla Corolla Hatchback GR Corolla [03/2019 - 09/2022] | ||
|
LO-beam Headlight does not Illuminate |
DESCRIPTION
The main body ECU (multiplex network body ECU) controls the low beam headlights.
WIRING DIAGRAM
for LED Type Turn Signal Light
for Bulb Type Turn Signal Light
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
![2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 09/2019]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)
- *: w/ Smart Key System
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(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 |
|---|---|---|---|
|
Headlight Relay |
Low beam headlights |
OFF or ON |
- |
Body Electrical > Main Body > Active Test
|
Tester Display |
|---|
|
Headlight Relay |
OK:
Low beam headlights illuminate.
|
Result |
Proceed to |
|---|---|
|
OK |
A |
|
NG (for LH Side) (for LED Type Turn Signal Light) |
B |
|
NG (for LH Side) (for Bulb Type Turn Signal Light) |
C |
|
NG (for RH Side) (for LED Type Turn Signal Light) |
D |
|
NG (for RH Side) (for Bulb Type Turn Signal Light) |
E |
| A |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE
|
| C |
|
| D |
|
| E |
|
|
|
2. |
INSPECT HEADLIGHT ASSEMBLY LH (LO TERMINAL VOLTAGE) |
|
*a |
Front view of wire harness connector (to Headlight Assembly LH) |
(a) Disconnect the A81 headlight assembly LH connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A81-3 (LO) - Body ground |
Light control switch in head position |
11 to 14 V |
| NG |
|
|
|
3. |
CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY LH - BODY GROUND) |
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A81-4 (E) - Body ground |
Always |
Below 1 Ω |
|
Result |
Proceed to |
|---|---|
|
OK (for TMC Made) |
A |
|
OK (for TMMMS Made) |
B |
|
NG |
C |
| A |
|
| B |
|
| C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
4. |
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT ASSEMBLY LH) |
(a) Disconnect the 1B No. 1 integration relay connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1B-1 - A81-3 (LO) |
Always |
Below 1 Ω |
|
1B-1 or A81-3 (LO) - Body ground |
Always |
10 kΩ or higher |
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
5. |
INSPECT HEADLIGHT ASSEMBLY LH (LO TERMINAL VOLTAGE) |
|
*a |
Front view of wire harness connector (to Headlight Assembly LH) |
(a) Disconnect the A29 headlight assembly LH connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A29-2 (LO) - Body ground |
Light control switch in head position |
11 to 14 V |
| NG |
|
|
|
6. |
CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY LH - BODY GROUND) |
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A29-3 (E) - Body ground |
Always |
Below 1 Ω |
|
Result |
Proceed to |
|---|---|
|
OK (for TMC Made) |
A |
|
OK (for TMMMS Made) |
B |
|
NG |
C |
| A |
|
| B |
|
| C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
7. |
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT ASSEMBLY LH) |
(a) Disconnect the 1B No. 1 integration relay connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1B-1 - A29-2 (LO) |
Always |
Below 1 Ω |
|
1B-1 or A29-2 (LO) - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
8. |
INSPECT NO. 1 INTEGRATION RELAY |
(a) Remove the No. 1 integration relay.
Click here
(b) Inspect the No. 1 integration relay.
Click here
| NG |
|
|
|
9. |
CHECK HARNESS AND CONNECTOR (POWER SOURCE - NO. 1 INTEGRATION RELAY) |
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1A-5 - Body ground |
Always |
11 to 14 V |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
10. |
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |
(a) Disconnect the 4B 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 |
|---|---|---|
|
1B-2 - 4B-31 |
Always |
Below 1 Ω |
|
1B-2 or 4B-31 - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
11. |
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-31 - MB-15 (HRLY) |
Always |
Below 1 Ω |
| OK |
|
| NG |
|
|
12. |
INSPECT HEADLIGHT ASSEMBLY RH (LO TERMINAL VOLTAGE) |
|
*a |
Front view of wire harness connector (to Headlight Assembly RH) |
(a) Disconnect the A80 headlight assembly RH connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A80-3 (LO) - Body ground |
Light control switch in head position |
11 to 14 V |
| NG |
|
|
|
13. |
CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY RH - BODY GROUND) |
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A80-4 (E) - Body ground |
Always |
Below 1 Ω |
|
Result |
Proceed to |
|---|---|
|
OK (for TMC Made) |
A |
|
OK (for TMMMS Made) |
B |
|
NG |
C |
| A |
|
| B |
|
| C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
14. |
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT ASSEMBLY RH) |
(a) Disconnect the 1A No. 1 integration relay connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1A-12 - A80-3 (LO) |
Always |
Below 1 Ω |
|
1A-12 or A80-3 (LO) - Body ground |
Always |
10 kΩ or higher |
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
15. |
INSPECT HEADLIGHT ASSEMBLY RH (LO TERMINAL VOLTAGE) |
|
*a |
Front view of wire harness connector (to Headlight Assembly RH) |
(a) Disconnect the A27 headlight assembly RH connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A27-2 (LO) - Body ground |
Light control switch in head position |
11 to 14 V |
| NG |
|
|
|
16. |
CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY RH - BODY GROUND) |
(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A27-3 (E) - Body ground |
Always |
Below 1 Ω |
|
Result |
Proceed to |
|---|---|
|
OK (for TMC Made) |
A |
|
OK (for TMMMS Made) |
B |
|
NG |
C |
| A |
|
| B |
|
| C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
17. |
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT ASSEMBLY RH) |
(a) Disconnect the 1A No. 1 integration relay connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1A-12 - A27-2 (LO) |
Always |
Below 1 Ω |
|
1A-12 or A27-2 (LO) - Body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
18. |
INSPECT NO. 1 INTEGRATION RELAY |
(a) Remove the No. 1 integration relay.
Click here
(b) Inspect the No. 1 integration relay.
Click here
| NG |
|
|
|
19. |
CHECK HARNESS AND CONNECTOR (POWER SOURCE - NO. 1 INTEGRATION RELAY) |
(a) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1B-8 - Body ground |
Always |
11 to 14 V |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
20. |
CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)) |
(a) Disconnect the I85 main body ECU (multiplex network body ECU) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
1A-11 - I85-12 (HRY2) |
Always |
Below 1 Ω |
|
1A-11 or I85-12 (HRY2) - Body ground |
Always |
10 kΩ or higher |
| OK |
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|