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.
Click here .gif)
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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