Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM100000001H5VT
Model Year Start: 2020 Model: Corolla Prod Date Range: [01/2019 - 09/2022]
Title: LIGHTING (EXT): LIGHTING SYSTEM (for HV Model): B2430,B2431; LED Headlight LH; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

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:
    • Power switch on (READY)
    • 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

B2431

LED Headlight RH

Detection condition:

  • All of the following conditions are met:
    • Power switch on (READY)
    • 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

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.

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PROCEDURE

1.

CLEAR DTC

(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 / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > Main Body > Clear DTCs

NEXT

2.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

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

(c) Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.

(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
A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 12

B

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
NG

GO TO STEP 7

OK

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
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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

Power switch on (IG)

11 to 14 V
OK

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NG

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
OK

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NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT UNIT ASSEMBLY LH)

(a) Disconnect the 2B 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

2B-1 - A81-3 (LO)

Always

Below 1 Ω

2B-1 or A81-3 (LO) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

INSPECT NO. 1 INTEGRATION RELAY

(a) Remove the No. 1 integration relay.

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(b) Inspect the No. 1 integration relay.

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NG

REPLACE NO. 1 INTEGRATION RELAY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL

OK

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

2A-5 - Body ground

Power switch off

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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

2B-2 - 4B-31

Always

Below 1 Ω

2B-2 or 4B-31 - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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.

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(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

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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

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
NG

GO TO STEP 16

OK

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
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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

Power switch on (IG)

11 to 14 V
OK

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NG

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
OK

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NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

16.

CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT UNIT ASSEMBLY RH)

(a) Disconnect the 2A 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

2A-12 - A80-3 (LO)

Always

Below 1 Ω

2A-12 or A80-3 (LO) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

17.

INSPECT NO. 1 INTEGRATION RELAY

(a) Remove the No. 1 integration relay.

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(b) Inspect the No. 1 integration relay.

Click here 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: INSPECTION

NG

REPLACE NO. 1 INTEGRATION RELAY 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [01/2019 - 03/2019]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL 2020 - 2022 MY Corolla Corolla Hatchback Corolla HV GR Corolla [03/2019 - 09/2022]; POWER DISTRIBUTION: INTEGRATION RELAY: REMOVAL

OK

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

2B-8 - Body ground

Power switch off

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

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

2A-11 - I85-12 (HRY2)

Always

Below 1 Ω

2A-11 or I85-12 (HRY2) - Body ground

Always

10 kΩ or higher
OK

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NG

REPAIR OR REPLACE HARNESS OR CONNECTOR