I am working on an 8 series with an AD-1 code. Another tech was trying to wire in a 12V accessory plug and attempted to wire into the fuse box in an empty relay socket. The relay is labeled NTRL ST and is next to the LPG main relay but I can't find it in the schematics. I am assuming the 12V switched coil power comes from the ECM and has caused this code. The wiring has been removed and I have checked all of the A20, A21, and A36 connections. Any ideas?