So I installed a relay at the BCM to disable the drl system so my hids would stop flickering in the day but I kept getting a service vehicle soon message on the dic, so I scanned with a tech 2 and got the bcm 1390 code for Device Voltage Reference Input Circuit. I removed the relay and soldered everything back up and am still getting this code. I followed the troubleshooting procedure on GM SI and now I'm on the step for replacing the BCM which I dont want to do. I checked for shorts and any other reason I might be getting this code. My battery is a little low, its only at 12v not the ful 12.6v. This could be the reason but I kinda doubt it.
Any thoughts? I want the message gone asap!