Toyota Camry (XV70): LED Headlight LH (B2430,B2431)

Toyota Camry Repair Manual XV70 (2018-2024) / Vehicle Exterior / Lighting (ext) / Lighting System / LED Headlight LH (B2430,B2431)

DESCRIPTION

These DTCs are stored when the low beam headlights do not illuminate, or a communication malfunction is detected between the light control LED 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 LED 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 LED ECU malfunction Headlight assembly LH malfunction Light control LED ECU power source and signal malfunction Malfunction Time: 10 seconds or more	Headlight assembly LH H-LP LH 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: Engine running Low beam headlights on Malfunction Status: Any of the following conditions is met: Light control LED ECU malfunction Headlight assembly RH malfunction Light control LED ECU power source and signal malfunction Malfunction Time: 10 seconds or more	Headlight assembly RH H-LP RH relay Main body ECU (multiplex network body ECU) Harness or connector	Main Body

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 LED ECU malfunction
- Headlight assembly LH malfunction
- Light control LED ECU power source and signal malfunction

Malfunction Time:

10 seconds or more

Headlight assembly LH
H-LP LH 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:
- Engine running
- Low beam headlights on

Malfunction Status:

Any of the following conditions is met:
- Light control LED ECU malfunction
- Headlight assembly RH malfunction
- Light control LED ECU power source and signal malfunction

Malfunction Time:

10 seconds or more

Headlight assembly RH
H-LP RH 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.*
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 ASSEMBLY LH (LO TERMINAL VOLTAGE)

for Bulb Type Turn Signal Light

for LED Type Turn Signal Light

Front view of wire harness connector

(to Headlight Assembly LH)

(a) Disconnect the A51*1 or A75*2 headlight assembly LH connector.

*1: for Bulb Type Turn Signal Light
*2: for LED Type Turn Signal Light

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

Standard Voltage:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A51-3 (LO) - Body ground	Light control switch in head position	11 to 14 V

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A75-4 (LO) - Body ground	Light control switch in head position	11 to 14 V

GO TO STEP 7

4.	CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY LH - BODY GROUND)

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

Standard Resistance:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A51-1 (E) - Body ground	Always	Below 1 Ω

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A75-8 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.	INSPECT HEADLIGHT ASSEMBLY LH (S TERMINAL VOLTAGE)

for Bulb Type Turn Signal Light

for LED Type Turn Signal Light

Front view of wire harness connector

(to Headlight Assembly LH)

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

Standard Voltage:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A51-2 (S) - Body ground	Ignition switch ON	11 to 14 V

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A75-7 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT ASSEMBLY LH

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

(a) Disconnect the K51 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A51-2 (S) - K51-14 (LLEW)	Always	Below 1 Ω
A51-2 (S) or K51-14 (LLEW) - Body ground	Always	10 kΩ or higher

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A75-7 (S) - K51-14 (LLEW)	Always	Below 1 Ω
A75-7 (S) or K51-14 (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 (H-LP LH RELAY - HEADLIGHT ASSEMBLY LH)

(a) Remove the H-LP LH relay.

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

Standard Resistance:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
3 (H-LP LH relay) - A51-3 (LO)	Always	Below 1 Ω
3 (H-LP LH relay) or A51-3 (LO) - Body ground	Always	10 kΩ or higher

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
3 (H-LP LH relay) - A75-4 (LO)	Always	Below 1 Ω
3 (H-LP LH relay) or A75-4 (LO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.	INSPECT H-LP LH RELAY

(a) Inspect the H-LP LH relay.

Click here

REPLACE H-LP LH RELAY

9.	CHECK HARNESS AND CONNECTOR (POWER SOURCE - H-LP LH RELAY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
2 (H-LP LH relay) - Body ground	Always	11 to 14 V
5 (H-LP LH relay) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

10.	CHECK HARNESS AND CONNECTOR (H-LP LH RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 3C 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
1 (H-LP LH relay) - 3C-31	Always	Below 1 Ω
1 (H-LP LH relay) or 3C-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 instrument panel junction block assembly.

Click here

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3C-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 ASSEMBLY RH (LO TERMINAL VOLTAGE)

for Bulb Type Turn Signal Light

for LED Type Turn Signal Light

Front view of wire harness connector

(to Headlight Assembly RH)

(a) Disconnect the A50*1 or A74*2 headlight assembly RH connector.

*1: for Bulb Type Turn Signal Light
*2: for LED Type Turn Signal Light

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

Standard Voltage:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A50-3 (LO) - Body ground	Light control switch in head position	11 to 14 V

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A74-4 (LO) - Body ground	Light control switch in head position	11 to 14 V

GO TO STEP 16

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:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A50-1 (E) - Body ground	Always	Below 1 Ω

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A74-8 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	INSPECT HEADLIGHT ASSEMBLY RH (S TERMINAL VOLTAGE)

for Bulb Type Turn Signal Light

for LED Type Turn Signal Light

Front view of wire harness connector

(to Headlight Assembly RH)

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

Standard Voltage:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A50-2 (S) - Body ground	Ignition switch ON	11 to 14 V

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A74-7 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT ASSEMBLY RH

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

(a) Disconnect the K51 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A50-2 (S) - K51-15 (RLEW)	Always	Below 1 Ω
A50-2 (S) or K51-15 (RLEW) - Body ground	Always	10 kΩ or higher

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
A74-7 (S) - K51-15 (RLEW)	Always	Below 1 Ω
A74-7 (S) or K51-15 (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 (H-LP RH RELAY - HEADLIGHT ASSEMBLY RH)

(a) Remove the H-LP RH relay.

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

Standard Resistance:

for Bulb Type Turn Signal Light

Tester Connection	Condition	Specified Condition
3 (H-LP RH relay) - A50-3 (LO)	Always	Below 1 Ω
3 (H-LP RH relay) or A50-3 (LO) - Body ground	Always	10 kΩ or higher

for LED Type Turn Signal Light

Tester Connection	Condition	Specified Condition
3 (H-LP RH relay) - A74-4 (LO)	Always	Below 1 Ω
3 (H-LP RH relay) or A74-4 (LO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

17.	INSPECT H-LP RH RELAY

(a) Inspect the H-LP RH relay.

Click here

REPLACE H-LP RH RELAY

18.	CHECK HARNESS AND CONNECTOR (POWER SOURCE - H-LP RH RELAY)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
2 (H-LP RH relay) - Body ground	Always	11 to 14 V
5 (H-LP RH relay) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

19.	CHECK HARNESS AND CONNECTOR (H-LP RH RELAY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Disconnect the K52 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
1 (H-LP RH relay) - K52-12 (HRY2)	Always	Below 1 Ω
1 (H-LP RH relay) or K52-12 (HRY2) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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Check Mode Procedure

CHECK MODE PROCEDURE HINT: Compared to normal mode, check mode is more sensitive to malfunctions. Therefore, check mode can detect malfunctions that cannot be detected in normal mode. NOTICE: All the stored DTCs and freeze frame data are cleared if: 1) the ECM is changed from normal mode to check

Toyota Camry (XV70): LED Headlight LH (B2430,B2431)

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