LIGHTING (EXT): LIGHTING SYSTEM: B243900,B243A00; Headlight LH Circuit; 2024 - 2025 MY RAV4 RAV4 HV [10/2023

Last Modified: 02-14-2025	6.11:8.1.0	Doc ID: RM100000002Q2HA
Model Year Start: 2024	Model: RAV4	Prod Date Range: [10/2023 - ]
Title: LIGHTING (EXT): LIGHTING SYSTEM: B243900,B243A00; Headlight LH Circuit; 2024 - 2025 MY RAV4 RAV4 HV [10/2023 - ]

DTC

B243900

Headlight LH Circuit

DTC

B243A00

Headlight RH Circuit

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).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	DTC Output from
B243900	Headlight LH Circuit	Detection condition: All of the following conditions are met: Ignition switch ON Low beam headlights on Malfunction status: Headlight assembly LH malfunction Open/short in Lo/Hi beam circuit Malfunction duration: 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
B243A00	Headlight RH Circuit	Detection condition: All of the following conditions are met: Ignition switch ON Low beam headlights on Malfunction status: Headlight assembly RH malfunction Open/short in Lo/Hi beam circuit Malfunction duration: 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.

PROCEDURE

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Main Body > Clear DTCs

2.	CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON (READY).

(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 18

3.	CHECK VEHICLE TYPE

Result	Proceed to
Turn Light for Bulb Type	A
Turn Light for LED Type	B

GO TO STEP 9

4.	CHECK HEADLIGHT ASSEMBLY LH (LO TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly LH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A99-1 (LO) - Body ground	Light control switch in HEAD position	11 to 14 V

GO TO STEP 8

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

(a) Disconnect the headlight assembly LH connector.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A99-6 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

6.	CHECK HEADLIGHT ASSEMBLY LH (S TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly LH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A99-4 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT ASSEMBLY LH

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

(a) Disconnect the A99 headlight assembly LH connector.

(b) Disconnect the G43 main body ECU (multiplex network body ECU) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A99-4 (S) - G43-14 (LLEW)	Always	Below 1 Ω
A99-4 (S) or G43-14 (LLEW) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

8.	CHECK HARNESS AND CONNECTOR (H-LP LH RELAY - HEADLIGHT ASSEMBLY LH)

(a) Remove the H-LP LH relay.

(b) Disconnect the A99 headlight assembly LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (H-LP LH relay) - A99-1 (LO)	Always	Below 1 Ω
3 (H-LP LH relay) or A99-1 (LO) - Body ground	Always	10 kΩ or higher

GO TO STEP 14

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.	CHECK HEADLIGHT ASSEMBLY LH (LO TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly LH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A98-1 (LO) - Body ground	Light control switch in HEAD position	11 to 14 V

GO TO STEP 13

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

(a) Disconnect the headlight assembly LH connector.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A98-8 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

11.	CHECK HEADLIGHT ASSEMBLY LH (S TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly LH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A98-5 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT ASSEMBLY LH

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

(a) Disconnect the A98 headlight assembly LH connector.

(b) Disconnect the G43 main body ECU (multiplex network body ECU) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A98-5 (S) - G43-14 (LLEW)	Always	Below 1 Ω
A98-5 (S) or G43-14 (LLEW) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

13.	CHECK HARNESS AND CONNECTOR (H-LP LH RELAY - HEADLIGHT ASSEMBLY LH)

(a) Remove the H-LP LH relay.

(b) Disconnect the A98 headlight assembly LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (H-LP LH relay) - A98-1 (LO)	Always	Below 1 Ω
3 (H-LP LH relay) or A98-1 (LO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	INSPECT H-LP LH RELAY

(a) Remove the H-LP LH relay.

(b) Inspect the H-LP LH relay.

Click here

REPLACE H-LP LH RELAY

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

(a) Remove the H-LP LH relay.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
2 (H-LP LH relay) - Body ground	Ignition switch off	11 to 14 V
5 (H-LP LH relay) - Body ground	Ignition switch off	11 to 14 V

*a	Front view of wire harness connector (to H-LP LH Relay)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Remove the H-LP LH relay.

(b) Disconnect the 4F instrument panel junction block assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (H-LP LH relay) - 4F-31	Always	Below 1 Ω
1 (H-LP LH relay) or 4F-31 - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

17.	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
4F-31 - A-15 (HRLY)	Always	Below 1 Ω

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

18.	CHECK VEHICLE TYPE

Result	Proceed to
Turn Light for Bulb Type	A
Turn Light for LED Type	B

GO TO STEP 24

19.	CHECK HEADLIGHT ASSEMBLY RH (LO TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly RH connector.

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

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A97-1 (LO) - Body ground	Light control switch in HEAD position	11 to 14 V

GO TO STEP 23

20.	CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY RH - BODY GROUND)

(a) Disconnect the headlight assembly RH connector.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A97-6 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

21.	INSPECT HEADLIGHT ASSEMBLY RH (S TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly RH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A97-4 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT ASSEMBLY RH

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

(a) Disconnect the A97 headlight assembly RH connector.

(b) Disconnect the G43 main body ECU (multiplex network body ECU) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A97-4 (S) - G43-15 (RLEW)	Always	Below 1 Ω
A97-4 (S) or G43-15 (RLEW) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

23.	CHECK HARNESS AND CONNECTOR (H-LP RH RELAY - HEADLIGHT ASSEMBLY RH)

(a) Remove the H-LP RH relay.

(b) Disconnect the A97 headlight assembly RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (H-LP RH relay) - A97-1 (LO)	Always	Below 1 Ω
3 (H-LP RH relay) or A97-1 (LO) - Body ground	Always	10 kΩ or higher

GO TO STEP 29

REPAIR OR REPLACE HARNESS OR CONNECTOR

24.	CHECK HEADLIGHT ASSEMBLY RH (LO TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly RH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A96-1 (LO) - Body ground	Light control switch in HEAD position	11 to 14 V

GO TO STEP 28

25.	CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY RH - BODY GROUND)

(a) Disconnect the headlight assembly RH connector.

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A96-8 (E) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

26.	CHECK HEADLIGHT ASSEMBLY LH (S TERMINAL VOLTAGE)

(a) Disconnect the headlight assembly RH connector.

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

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
A96-5 (S) - Body ground	Ignition switch ON	11 to 14 V

REPLACE HEADLIGHT ASSEMBLY LH

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

(a) Disconnect the A96 headlight assembly RH connector.

(b) Disconnect the G43 main body ECU (multiplex network body ECU) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A96-5 (S) - G43-14 (LLEW)	Always	Below 1 Ω
A96-5 (S) or G43-14 (LLEW) - Body ground	Always	10 kΩ or higher

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

REPAIR OR REPLACE HARNESS OR CONNECTOR

28.	CHECK HARNESS AND CONNECTOR (H-LP LH RELAY - HEADLIGHT ASSEMBLY RH)

(a) Remove the H-LP RH relay.

(b) Disconnect the A96 headlight assembly RH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (H-LP RH relay) - A96-1 (LO)	Always	Below 1 Ω
3 (H-LP RH relay) or A96-1 (LO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

29.	INSPECT H-LP RH RELAY

(a) Remove the H-LP RH relay.

(b) Inspect the H-LP RH relay.

Click here

REPLACE H-LP RH RELAY

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

(a) Remove the H-LP RH relay.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
2 (H-LP RH relay) - Body ground	Ignition switch off	11 to 14 V
5 (H-LP RH relay) - Body ground	Ignition switch off	11 to 14 V

*a	Front view of wire harness connector (to H-LP RH Relay)

REPAIR OR REPLACE HARNESS OR CONNECTOR

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

(a) Remove the H-LP RH relay.

(b) Disconnect the G44 main body ECU (multiplex network body ECU) connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 (H-LP RH relay) - G44-12 (HRY2)	Always	Below 1 Ω
1 (H-LP RH relay) or G44-12 (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 duration:

Detection condition:

Malfunction status:

Malfunction duration:

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

Body Electrical > Main Body > Clear DTCs

Body Electrical > Main Body > Trouble Codes