tracking down an odd electrical (CCM) issue. am i headed in the right direction?

[JesterE34]

aparently searches for "check control" and "fog lights not working" yield all sorts of different responses on this and other sites. Ranging from "replace the box" to "your bulb is bad" to "your battery is bad"

I can't honestly believe i'm the only one with this issue, but from what i've found online it sure feels like i am. So here's a quick run down of my problem.

When i start the car i get a "Check Control" message on the dash. As long as the car is standing still, the message remains. Once i start moving (and i'm talking like just rolling forward) the message goes away and my dash is error free. During driving, the message never returns, but i cannot use my OBC button to cycle through temp,mpg etc on the dash. OBC still works at the unit itself. All functions are there, but nothing on the dash. When i turn the car off, the Check Control message comes back.

At the same time this happened, my fog lights stopped working. No green fog light on the dash, no error. Just nothing. Now, it could be just the switch and completely unrelated (i haven't had time to change the switch but i THINK i have a working one in my parts car that i'll swap out) but it just seemed odd that it happened at the same time.

Here's what i've done so far:
Checked fuses. all good.
Checked relays. all good.
Swapped out about 5 CCM's and 3 LKM's with no luck.
Swapped ECU's with no change.

Here's what i'm about to check/try:

Fusible link (i believe it is under the back seat in the 535i)
Fog light switch
break out the multimeter and check continuity in the OBC stalk switch
swap dash

Does anyone else have any ideas or experienced something similar? This all started after the car sat for about a year un-touched. I then fired it up on the first crank and it has been doing this ever since. It runs/drives fine, just has these odd electrical quirks every since it sat.

[Tiger]

I would also check your battery... seems like it because low voltage will cause numerous errors... the check control relies on voltage reading to be sure it is within spec. Relay won't work unless there is enough voltage.

[JesterE34]

oh yeah that was on my list too. forgot to type it. thanks

i think its absolutely silly as the car runs just fine and fires up with no problem but seems like everyone has said that they're picky about voltage, as opposed to amperage

[Tiger]

Not really... it is the battery cell that may be failing but the rest of the battery is fine... will start up car no problem but tons of electronic errors... especially on current cars with tons of diagnostic warnings and heavy electronic reliance. So how old is your battery?

[JesterE34]

it was new in 2010. sat in the car (unplugged) mid 2011 - 2012. plugged into a trickle charger over night before putting it back in the car around april 2012.

[Tiger]

What is the brand and model of trickle charger? ALot of them are junk and will fry your battery to death.

[JesterE34]

idk off the top of my head. snap on maybe? Mac? Cornwell? its the one at our shop. its a quality one used often on customer cars. not a cheap walmart one or anything like that.

[Tiger]

Well, the dumb one which is like magnetic charger will cook the battery to death. The electronic onw is intelligent one which knows how to cycle the battery charge and not cook the battery to death.

[Rustam]

Have you checked for short circuits at the OBC and CCM? How did you do it? Specifically, have you checked for continuity (zero resistance) to ground at every pin, and otherwise different resistance values, and where do they come from?

[JesterE34]

didn't get that in depth. gave it a nice charge this weekend and am going to hook up the battery today. This is all going to be a moot point though because i hope to have the megasquirt hooked up by the end of the month.