Lexus NX: Headlamp LH Circuit (B2439,B243A)
DESCRIPTION
This DTC is output when the headlight ECU sub-assembly receives an abnormal signal from the headlight unit.
The headlight ECU sub-assembly LH outputs DTC B2439 and B243A
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| B2439 | Headlamp LH Circuit | Headlight ECU sub-assembly LH light source malfunction |
|
| B243A | Headlamp RH Circuit | Headlight ECU sub-assembly RH light source malfunction |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
After the headlight ECU sub-assembly LH is replaced, vehicle information registration and initialization are necessary.
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PROCEDURE
| 1. | CHECK FOR DTC |
(a) Clear the DTCs.
Click here
(b) Turn the power switch on (IG).
(c) Inspect the light using the dimmer switch.
(d) Check for DTCs.
Click here
| Result | Proceed to |
|---|---|
| DTCs B2439 and B243A are not output | A |
| DTC B2439 is output | B |
| DTC B243A is output | C |
| A | .gif) | USE SIMULATION METHOD TO CHECK |
| C | | GO TO STEP 3 |
|
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| 2. | CHECK HEADLIGHT UNIT ASSEMBLY LH |
(a) Interchange the headlight unit assembly LH with RH and connect the connectors to them.
Click here
(b) Clear the DTCs.
Click here
(c) Check for DTCs.
Click here
| Result | Proceed to |
|---|---|
| DTC B2439 is output | A |
| DTC B243A is output | B |
| A | | REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH |
| B | | REPLACE HEADLIGHT UNIT ASSEMBLY LH |
| 3. | CHECK HEADLIGHT UNIT ASSEMBLY RH |
(a) Interchange the headlight unit assembly RH with LH and connect the connectors to them.
Click here
(b) Clear the DTCs.
Click here
(c) Check for DTCs.
Click here
| Result | Proceed to |
|---|---|
| DTC B243A is output | A |
| DTC B2439 is output | B |
| A | | REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH |
| B | | REPLACE HEADLIGHT UNIT ASSEMBLY RH |
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DESCRIPTION This DTC is output when the low beam fan is malfunctioning and the low beam illumination is dark. The headlight ECU sub-assembly LH outputs DTC B243D and B243E DTC No. Detection Item
Vehicle Specifications have not been Stored (B2451)
DESCRIPTION This DTC is output if the vehicle variation information is not written to the headlight ECU sub-assembly LH. The headlight ECU sub-assembly LH outputs DTC B2451. DTC No. Detection Ite
Right Headlight ECU Variation Error (B2455)
DESCRIPTION This DTC is output when a headlight ECU sub-assembly RH that is incompatible with the vehicle is installed. The headlight ECU sub-assembly LH outputs DTC B2455. DTC No. Detection Item
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A communication malfunction DTC may be stored.
The radio receiver assembly may not
Disassembly
DISASSEMBLY CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH and LH side.
The procedure listed below is for the LH side.
PROCEDURE 1. PRECAUTION NOTICE: After turning the power switch off, waiting time may be required before disconnecting the cable from the auxiliary battery n
