Good afternoon, the headlamps are controlled with the integrated power module which is a actually the computer controlled fuse box under the hood, here is the related wiring diagram:
I recommend checking the left side low beam output wire at the fuse box connector to make sure it is coming out of the fuse box and not a wiring problem. The most likely problem is the fuse box itself and the only repair is replacement. There is one thing you could try before spending the money for the part which Im sure isnt cheap. Keep in mind that im not too sure what problems it could cause but you might be able to get away with splicing the left headlamp to the right side headlamp low beam. It may draw to much current, but then again it may work and say you the money of the fuse box. Its worth a try if you want or you can purchase the integrated power module.
Here is a wiring diagram for the connector at the fuse box (integrated power module).
You need to check the white and dark blue wire with the low beams on.
If this answers your question then please press ACCEPT. If you need more help then let me know. Thanks.