[jessevondoom]

I've been chasing a no crank, no start ghost in my 2006 325xi for about the last year. Currently at 164K miles and the engine runs well when it starts.

My issue started in September of 2019. At first it was an intermittent no crank, no start that would come and go. A second press of the starter button would usually do the trick at first, but after a week or so the car simply wouldn't start. Brought it to a local indy who does a lot of BMW work. He replaced the starter and seemingly fixed the issue. A few weeks later the no crank no start returned and I towed the car back to his shop. He installed a new CAS module that was coded by the local dealership and all was well.

It's been a year and about 2400 miles, but last week I noticed a slightly slow start. Ran some errands, and starting the car I heard a brief metallic rattle as it started, quick check under the hood but all seemed well and the engine was running strong. Driving home I heard a noise almost like a whistle/drill that lasted about 45 seconds then disappeared. Engine was still running well but I pulled into a grocery store parking lot and turned things off just in case. Nothing. Back to a complete no crank, no start.

After towing it home I checked for codes and had both 2E98 (no communication with alternator) and A0C1 (output, terminal 50.)

Alternator still spins freely so it's not seized, but can't test output without things running. Battery voltage was low (12.1V) and the battery was old when I got the car three years ago, so I put in a replacement as I was planning on that anyway. Registered it with Bimmergeeks Pro Tool and replaced the upper ground strap while I was at it. Good voltage. Cleared codes and tried firing things up. Still no crank, no start, and the A0C1 error is still present.

Checked every relevant fuse I could think of and they're all fine. When this started last year we swapped in new relays and that wasn't it — though I haven't tried again this time. The earth strap down by the starter is a little green and frayed but has some life. I've got a replacement but I don't think that's the issue. After that I'm out of ideas, other than just inspecting wiring for damage.

So nutshell:

• New starter
• New CAS module
• New battery
• IBS connected / not connected doesn't make a difference
• Battery cables look good
• Alternator might be going, but would that cause an A0C1 no crank, no start?

Any help or ideas would be really appreciated.

[Jacob04250628]

Did you ever figure out what’s wrong with it ?