[goblinslop]

I have been chasing a ridiculous electrical issue on my 2007 335i sedan for quite some time now. It first started when the car died suddenly while driving and had to be jump started. I first replaced the voltage regulator and then the battery with no luck. I also measured the output of the alternator directly from its positive terminal and it put out a steady 13.8v at idle. I then checked the grounds and cleaned most of the connections on the B+ circuit in the engine bay, both to no avail. I checked parasitic draw, and had it measure over 8amps, leading me believe I was finally getting somewhere. As is recommended, I let the car fully sleep and began pulling fused one by one, but every fuse I pulled seemed to lower the parasitic draw a tiny bit. The draw falls to around 3 amps when I pull the CAS, footwell module, and B+ potential distributor fuses, but that is as low as I have gotten it to go. I would greatly appreciate any insight or advice on this issue.

[GoRomeo]

Originally Posted by goblinslop

I have been chasing a ridiculous electrical issue on my 2007 335i sedan for quite some time now. It first started when the car died suddenly while driving and had to be jump started. I first replaced the voltage regulator and then the battery with no luck. I also measured the output of the alternator directly from its positive terminal and it put out a steady 13.8v at idle. I then checked the grounds and cleaned most of the connections on the B+ circuit in the engine bay, both to no avail. I checked parasitic draw, and had it measure over 8amps, leading me believe I was finally getting somewhere. As is recommended, I let the car fully sleep and began pulling fused one by one, but every fuse I pulled seemed to lower the parasitic draw a tiny bit. The draw falls to around 3 amps when I pull the CAS, footwell module, and B+ potential distributor fuses, but that is as low as I have gotten it to go. I would greatly appreciate any insight or advice on this issue.

I wonder what led you to replace the voltage regulator and battery? Did you read fault codes when this happened?

[Frozz]

I had this same issue, my issue was the JBE body control module under the fuse box. You must remove the glove box and find it under the fuse panel. You'll need a Torx, Phillips screwdriver, and small hands. Make sure when you pull yours that you note "JFBBFE III", "JFBBFE II" or "JFBBFE I" as you will need to match the replacement. They can be found on eBay for about $50. I'd also keep an eye on that alternator voltage as it could be overvolting intermittently(which was the cause of my JBE failure).

Also, are you sure the car is fully sleeping? Full sleep would make the gear selector indicator light turn off.