I got the check engine light, read the codes 1-2-1. Checked the main relay to the best of my ability, per the Bently manual. I know the bently is for the 240 series but i have the B230f engine in the 740. Tried to check the 87-1 but did not find the 87-2 mentioned in the bently. I did get a reading from the 87-1. I then tried the #30 terminal but did not get a voltage reading. I did remove both of the relays behind the glove box and reinstalled them. The car seems to be running fine now. I also cleared the codes after reading them. The check engine light came on a few months ago and I read the code with the same 1-2-1 reading. I only read the codes then and the car ran fine for the past few months. I do not believe the problem is in the AMM but maybe a signal to it.

Not sure what to do next, short of taking it to the mechanic.

could use some help. Keep feeling the problem is minor or simple to fix but difficult to find.

Thanks