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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Left Low Beam Fan Malfunction (B243D,B243E)
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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System Diagram
SYSTEM DIAGRAM CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Component Function Front door outside handle assembly Receives request signals from the certification ECU (smart key ECU assembly) via the built-in electrical key antenna (front door) and forms the vehicle exterior detection area
Data List / Active Test
DATA LIST / ACTIVE TEST READ DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may b
