DTC B2439: Headlight LH Circuit; DTC B243A: Headlight RH Circuit [10/2018 - ]: Description
The No. 1 headlight ECU sub-assembly LH and No. 1 headlight ECU sub-assembly RH internally boost the power supply voltage to ensure a constant supplied current for the lo/hi beam LED of their respective headlight.
By monitoring the LED power supply voltage, abnormal current and malfunctions can be detected.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | DTC Output from |
|---|---|---|---|---|
| B2439 | Headlight LH Circuit | Detection condition:
Malfunction status:
Malfunction duration:
|
|
AFS |
| B243A | Headlight RH Circuit | Detection condition:
Malfunction status:
Malfunction duration:
|
|
AFS (Sub) |
DTC DETECTION CONDITIONS (B2439):
| Vehicle Condition | ||||
|---|---|---|---|---|
| Pattern 1 | Pattern 2 | Pattern 3 | ||
| Diagnosis Condition | Ignition switch ON | ◦ | ◦ | ◦ |
| Low beam headlights on | ◦ | ◦ | ◦ | |
| Malfunction Status | headlight unit LH malfunction | ◦ | - | - |
| Open in Lo/Hi beam circuit | - | ◦ | - | |
| Short in Lo/Hi beam circuit | - | - | ◦ | |
| Detection Time | 10 seconds or more | 10 seconds or more | 10 seconds or more | |
| Number of Trips | - | - | - | |
DTC DETECTION CONDITIONS (B243A):
| Vehicle Condition | ||||
|---|---|---|---|---|
| Pattern 1 | Pattern 2 | Pattern 3 | ||
| Diagnosis Condition | Ignition switch ON | ◦ | ◦ | ◦ |
| Low beam headlights on | ◦ | ◦ | ◦ | |
| Malfunction Status | headlight unit RH malfunction | ◦ | - | - |
| Open in Lo/Hi beam circuit | - | ◦ | - | |
| Short in Lo/Hi beam circuit | - | - | ◦ | |
| Detection Time | 10 seconds or more | 10 seconds or more | 10 seconds or more | |
| Number of Trips | - | - | - | |
HINT:
DTC will be output when conditions for either of the patterns in the table above are met.