B1D02-15 and B1D03-15 fault codes, no headlight flash unless headlights turned on

[wombatjg]

I have fault codes of B1D02-15 and B1D03-15 (high beam circuit, General electrical failure, circuit short to battery or open).

In basic terms, I try and flash my headlights when they are not turned on, and they do not work, but the blue light comes on the dash. When the headlights are turned on, and I pull the light stick forward to flash, they flash, no issues.

Headlights are LR052379 and LR052388

Can somebody please help.

Thank you.

 

[Shaggy]

First question, are the bulbs stock halogens or has the truck had an LED conversion at some point? Those two codes are the left and right high beam circuit monitors, and aftermarket LED bulbs are the number one cause of exactly this kind of complaint, because the module sees the wrong load on the circuit even though the lights physically work.

If the bulbs are stock, next stop is the connectors on the back of each headlamp. Heat cycling gets to them and a corroded or melted high beam pin will throw the same faults. Worth unplugging both and having a look before throwing parts at it.

 

[wombatjg]

First question, are the bulbs stock halogens or has the truck had an LED conversion at some point? Those two codes are the left and right high beam circuit monitors, and aftermarket LED bulbs are the number one cause of exactly this kind of complaint, because the module sees the wrong load on the circuit even though the lights physically work.

If the bulbs are stock, next stop is the connectors on the back of each headlamp. Heat cycling gets to them and a corroded or melted high beam pin will throw the same faults. Worth unplugging both and having a look before throwing parts at it.

Thank you. Bulbs are stock xenon. I will check out the connectors, thank you for pointing me in that direction.