MicroHacker Forum

Did anyone find a way how to autostart foglights to work as DRLs?
Without relay or hardware.

Its not possible without modification in BCM firmware.

anybody sniffed on CAN signal when button for fogs is on?

Light switch module is connected to bcm via LIN bus. Fog light are connected directly to BCM. All logic and relay functions are closed in bcm. I think than on mscan you can find only status of this light.

amplified wrote: ↑11 Mar 2020, 21:32 anybody sniffed on CAN signal when button for fogs is on?

i have a capture of the LIN bus from the switch if its of any help

tasicky wrote: ↑12 Mar 2020, 18:49 I think than on mscan you can find only status of this light.

Correct, like for many other signals also. As the foglights are also directly connected to the BCM, all logic is inside this module. The only chance i see to control it via CAN from outside the BCM is to use service control routines of diagnostic services. I don't know how but i am absolutely shure that there exists service calls to get every input signal status and set every output status. BUT - establishing a diagnostic session while driving is maybe a BAD idea

Hi,

I think you can do it with a relay... It is more simple.