LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model without AFS): B2430,B2431; LED Headlight LH; 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001GL8S
Model Year Start: 2020	Model: GR Corolla	Prod Date Range: [01/2019 - 03/2019]
Title: LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model without AFS): B2430,B2431; LED Headlight LH; 2020 MY Corolla Corolla Hatchback GR Corolla [01/2019 - 03/2019]

DTC

B2430

LED Headlight LH

DTC

B2431

LED Headlight RH

DESCRIPTION

These DTCs are stored when the low beam headlights do not illuminate, or a communication malfunction is detected between the light control ECU and main body ECU (multiplex network body ECU).

HINT:

DTC B2430 or DTC B2431 may also be stored if a headlight cooling fan is malfunctioning. In this case, the light control ECU will dim or turn off the malfunctioning low beam headlight.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	DTC Output from
B2430	LED Headlight LH	Detection condition: All of the following conditions are met: Engine running Low beam headlights on Malfunction Status: Any of the following conditions is met: Light control ECU malfunction Headlight unit assembly LH malfunction Light control ECU power source and signal malfunction Malfunction Time: 10 seconds or more	Headlight unit assembly LH No. 1 integration relay Instrument panel junction block assembly Main body ECU (multiplex network body ECU) Harness or connector	Main body ECU (multiplex network body ECU)
B2431	LED Headlight RH	Detection condition: All of the following conditions are met: Engine running Low beam headlights on Malfunction Status: Any of the following conditions is met: Light control ECU malfunction Headlight unit assembly RH malfunction Light control ECU power source and signal malfunction Malfunction Time: 10 seconds or more	Headlight unit assembly RH No. 1 integration relay Main body ECU (multiplex network body ECU) Harness or connector	Main body ECU (multiplex network body ECU)

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
- *: w/ Smart Key System

PROCEDURE

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(d) Enter the following menus: Body Electrical / Main Body / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > Main Body > Clear DTCs

2.	CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / Main Body / Trouble Codes.

(f) Check for DTCs.

Body Electrical > Main Body > Trouble Codes

OK:

DTC B2430 and B2431 are not output.

Result	Proceed to
OK	A
NG (DTC B2430 is output)	B
NG (DTC B2431 is output)	C

USE SIMULATION METHOD TO CHECK

GO TO STEP 12

3.	INSPECT HEADLIGHT UNIT ASSEMBLY LH (LO TERMINAL VOLTAGE)

*a	Front view of wire harness connector (to Headlight Unit Assembly LH)

(a) Disconnect the A81 headlight unit 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

GO TO STEP 7

4.	CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT 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

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	INSPECT HEADLIGHT UNIT ASSEMBLY LH (S TERMINAL VOLTAGE)

*a	Front view of wire harness connector (to Headlight Unit Assembly LH)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A81-5 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT UNIT ASSEMBLY LH

6.	CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT ASSEMBLY LH - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the I86 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
A81-5 (S) - I86-14 (LLEW)	Always	Below 1 Ω
A81-5 (S) or I86-14 (LLEW) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT UNIT 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

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

REPLACE NO. 1 INTEGRATION RELAY

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

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

11.	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
4B-31 - MB-15 (HRLY)	Always	Below 1 Ω

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

12.	INSPECT HEADLIGHT UNIT ASSEMBLY RH (LO TERMINAL VOLTAGE)

*a	Front view of wire harness connector (to Headlight Unit Assembly RH)

(a) Disconnect the A80 headlight unit 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

GO TO STEP 16

13.	CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT 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

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	INSPECT HEADLIGHT UNIT ASSEMBLY RH (S TERMINAL VOLTAGE)

*a	Front view of wire harness connector (to Headlight Unit Assembly RH)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A80-5 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT UNIT ASSEMBLY RH

15.	CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT ASSEMBLY RH - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the I86 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
A80-5 (S) - I86-15 (RLEW)	Always	Below 1 Ω
A80-5 (S) or I86-15 (RLEW) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

16.	CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT UNIT 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

REPAIR OR REPLACE HARNESS OR CONNECTOR

17.	INSPECT NO. 1 INTEGRATION RELAY

(a) Remove the No. 1 integration relay.

Click here

(b) Inspect the No. 1 integration relay.

Click here

REPLACE NO. 1 INTEGRATION RELAY

18.	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

REPAIR OR REPLACE HARNESS OR CONNECTOR

19.	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

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

DESCRIPTION

Detection condition:

Malfunction Status:

Malfunction Time:

Detection condition:

Malfunction Status:

Malfunction Time:

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

Body Electrical > Main Body > Clear DTCs

Body Electrical > Main Body > Trouble Codes