Lexus NX: Headlight Leveling Motor LH Communication Malfunction (B2424,B2410,B2411,B2425)

DESCRIPTION

Each headlight ECU sub-assembly and headlight swivel and leveling motor communicate via LIN communication.

The headlight swivel and leveling motor operates according to power supplied and automatic headlight beam level control signals from its respective headlight ECU sub-assembly and sends its operating state to the headlight ECU sub-assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B2410	Headlight Swivel Motor LH Communication Malfunction	Power switch on (IG) LIN communication error 10 seconds or more	Headlight unit assembly LH Headlight ECU sub-assembly LH
B2411	Headlight Swivel Motor RH Communication Malfunction	Power switch on (IG) LIN communication error 10 seconds or more	Headlight unit assembly RH Harness or connector Headlight ECU sub-assembly RH Headlight ECU sub-assembly LH
B2424	Headlight Leveling Motor LH Communication Malfunction	Power switch on (IG) LIN communication error 10 seconds or more	Headlight unit assembly LH Headlight ECU sub-assembly LH
B2425	Headlight Leveling Motor RH Communication Malfunction	Power switch on (IG) LIN communication error 10 seconds or more	Headlight unit assembly RH Harness or connector Headlight ECU sub-assembly RH Headlight ECU sub-assembly LH

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the headlight ECU sub-assembly LH.

Click here

PROCEDURE

1.	CHECK FOR DTC

(a) Clear the DTCs.

Click here

Body Electrical > AFS > Clear DTCs

(b) Turn the power switch on (IG) and wait for at least 10 seconds or more.

(c) Check for DTCs.

Click here

Body Electrical > AFS > Trouble Codes

OK:

DTC B2410, B2411, B2424 and B2425 are not outputs.

Result	Proceed to
OK	A
NG (DTC B2424 and B2425 are output)	B
NG (DTC B2424 is output)	C
NG (DTC B2425 is output)	D
NG (DTC B2410 and B2424 are output)	E
NG (DTC B2411 and B2425 are output)

A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 6

D

GO TO STEP 7

E

GO TO AFS (ADAPTIVE FRONT-LIGHTING SYSTEM)

B

2.	CHECK HEADLIGHT ASSEMBLY RH

(a) Disconnect the A20 headlight ECU sub-assembly RH connector.

(b) Clear the DTCs.

Click here

Body Electrical > AFS > Clear DTCs

(c) Turn the power switch on (IG) and wait for at least 10 seconds or more.

(d) Check for DTCs.

Click here

Body Electrical > AFS > Trouble Codes

Result	Proceed to
DTC B2424 and B2425 are output	A
DTC B2425 is output	B

B

GO TO STEP 5

A

3.	CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)

(a) Disconnect the A19 headlight ECU sub-assembly LH connector.

(b) Disconnect the A20 headlight ECU sub-assembly RH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A19-20(LINL) or A20-20(LINL) - Body ground	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.	CHECK HEADLIGHT UNIT ASSEMBLY LH

(a) Remove the headlight ECU sub-assembly LH.

Click here

(b) Reconnect the A19 headlight ECU sub-assembly LH connector.

(c) Clear the DTCs.

Click here

Body Electrical > AFS > Clear DTCs

(d) Turn the power switch on (IG) and wait for at least 10 seconds or more.

(e) Check for DTCs.

Click here

Body Electrical > AFS > Trouble Codes

Result	Proceed to
DTC B2424 and B2425 are output	A
DTC B2424 is output	B

A

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

B

REPLACE HEADLIGHT UNIT ASSEMBLY LH

5.	CHECK HEADLIGHT UNIT ASSEMBLY RH

(a) Remove the headlight ECU sub-assembly RH.

Click here

(b) Reconnect the A20 headlight ECU sub-assembly RH connector.

(c) Clear the DTCs.

Click here

Body Electrical > AFS > Clear DTCs

(d) Turn the power switch on (IG) and wait for at least 10 seconds or more.

(e) Check for DTCs.

Click here

Body Electrical > AFS > Trouble Codes

Result	Proceed to
DTC B2424 and B2425 are output	A
DTC B2425 is output	B

A

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH

B

REPLACE HEADLIGHT UNIT ASSEMBLY RH

6.	CHECK HEADLIGHT ECU SUB-ASSEMBLY LH

(a) Remove the headlight ECU sub-assembly LH as a unit with the connectors still connected.

Click here

(b) Disconnect the A20 headlight ECU sub-assembly RH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A20-20 (LINL) - C-13	Always	Below 1 Ω

OK

REPLACE HEADLIGHT UNIT ASSEMBLY LH

NG

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

7.	CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY LH - HEADLIGHT ECU SUB-ASSEMBLY RH)

(a) Disconnect the A19 headlight ECU sub-assembly LH connector.

(b) Disconnect the A20 headlight ECU sub-assembly RH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A19-20(LINL) - A20-20(LINL)	Always	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8.	CHECK HEADLIGHT ECU SUB-ASSEMBLY LH (LINL TERMINAL SIGNAL OUTPUT)

*a	Front view of wire harness connector (to Headlight ECU Sub-assembly RH)

(a) Disconnect the headlight ECU sub-assembly RH connector.

(b) Using the Techstream, check the waveform.

OK:

Tester Connection	Switch Condition	Specified Condition
A20-20 (LINL) - Body ground	Power switch on (IG)	Pulse generation

NG

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

OK

9.	CHECK HEADLIGHT ECU SUB-ASSEMBLY RH

(a) Remove the headlight ECU sub-assembly RH as a unit with the connectors still connected.

Click here

(b) Disconnect the A19 headlight ECU sub-assembly LH connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A19-20 (LINL) - C-13	Always	Below 1 Ω

OK

REPLACE HEADLIGHT UNIT ASSEMBLY RH

NG

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH

READ NEXT: