Starting Issue. Need Help

[codinge90]

I've been having starting issues in the morning. Almost every day (Sometimes it's every other day) when I go to start the car, I press the start/stop button and all the lights come on but no crank. I have to press the button 10-20 times to get it to start and sometimes have to let the car site with ignition off for 5 minutes.


To quickly go over the past 4 months.


January - Car died, battery was shot so I installed a new battery. Registered with BMW Carly. Battery was replaced with an O'Reillys AGM battery with the same exact specs as an OEM one.

March - Car died while on freeway, this happened twice. Alternator was tested and came back bad. Installed new OEM alternator. Right before the alternator went out I started noticing the starting issue. Starter issue has been going on since February. It didn't happen often at first but it's to the point now where it hasn't gotten worse but hasn't gotten better.

April - Finally took the car to a good indy shop locally, they ran a few tests and saw the battery was never registered properly. Battery registration shows 0 km (I'm at 97,000 miles). They told me to try to get a new battery since there is a possibility of harming the car if registering the battery again with whatever Carly did. I got a new battery and they registered the new battery with Autologic. They mentioned an unsuccessful battery registration could cause this issue but they more wanted to rule this out as a possible variable.


Since the new battery was installed, I still get the starting issue. It only takes me a few times pressing the start/stop button but it still persists. I went back to the INDY shop and they scanned the car and the car came back with:

A0C1 - Present - CAS: Output, Terminal 50

They said that there is a problem with the CAS communicating the to the DME and that the code has popped up 9 times since the new battery was registered. The battery was registered last week and I brought them the car today to scan. It is an intermittent error so it's a bit difficult for them to diagnose since the problem only happens on cold starts. Once I get the car started, I can leave it sitting for 4-6 hours and start it up no problem, it's only on cold starts when it acts up. They want me to drop the car off on Monday and leave it there overnight so they can replicate the problem and start testing voltage to see where exactly the problem lies. The shop owner said he would bet money it's not the Starter which I'm glad about since the labor involved in changing the starter is insane. The shop mentioned that they believe my CAS is bad and that possibly I'd need to replace it which isn't bad since I can program the CAS myself and the part itself is only 350 but I'd rather not go to that extent since there is a possibility that this could be a starter issue.

I've already tried disconnecting the IBS cable and it still persists so it is not an IBS issue. When I looked up A0C1 on the forums, most people that had this error had to replace their starter. The only thing is, the people that replaced their starter were throwing a lot more CAS codes than just A0C1. I also can't believe that my Battery, Alternator and Starter would all go out within 4 months of each other. The only thing I haven't checked is the engine ground cable, I'll have that checked in the next couple days. Does anyone have any ideas on what it could be or some things to test before taking it back to the shop on Monday?

[WingZeroX5]

You should read my thread, most likely the starter and I only had A0C1 and another code

http://www.m3post.com/forums/showthread.php?t=1319988

[codinge90]

Originally Posted by WingZeroX5

You should read my thread, most likely the starter and I only had A0C1 and another code

http://www.m3post.com/forums/showthread.php?t=1319988

That's what I'm suspecting but I'm very curious to the shop that has been diagnosing the problem. The shop owner said he'd put money on the fact it's not the starter but with all my searching online, no one has mentioned the CAS module being the problem. I guess I'll just have to wait to further diagnose

[doogee]

Being so intermittent, it's the starter. This is becoming very common on these engines.

Check your engine ground cable. If that's in good shape, then your starter solenoid is most than likely pooched.

http://www.m3post.com/forums/showthr...hlight=starter

http://www.m3post.com/forums/showthr...hlight=starter


The terminal 50 code in CAS could simply be popping up because it sees an issue after sending a signal to terminal 50 (starter solenoid) but the starter is not engaging.

[codinge90]

Originally Posted by doogee

Being so intermittent, it's the starter. This is becoming very common on these engines.

Check your engine ground cable. If that's in good shape, then your starter solenoid is most than likely pooched.

http://www.m3post.com/forums/showthr...hlight=starter

http://www.m3post.com/forums/showthr...hlight=starter


The terminal 50 code in CAS could simply be popping up because it sees an issue after sending a signal to terminal 50 (starter solenoid) but the starter is not engaging.

Don't you think this issue being relevant for 3-4 months and having not gotten worse or better it's not the starter? If it was the starter wouldn't it have gotten worse over time?

[doogee]

Originally Posted by codinge90

Don't you think this issue being relevant for 3-4 months and having not gotten worse or better it's not the starter? If it was the starter wouldn't it have gotten worse over time?

I myself had similar issues with my starter for a few months before I replaced it.

Depends how much driving you do.

If you trust your mechanic, then follow what they say I suppose. But I predict an expensive CAS replacement followed by a starter replacement after.


Diagnosing this problem is really simple and I'm surprised they haven't tried this.

1. Pull the intake plenum off (10 minutes)
2. Access starter solenoid control wire
3. Have someone cycle the start button and check for voltage on the signal wire at the starter.

If it fires everytime, it's the starter.

[WingZeroX5]

Originally Posted by codinge90

Don't you think this issue being relevant for 3-4 months and having not gotten worse or better it's not the starter? If it was the starter wouldn't it have gotten worse over time?

Not necessarily, mine was working for a year. During the warmer months, it's like as if nothing is going wrong. Then as it got cold again and finally in November on one cold morning, *click*

[codinge90]

Originally Posted by doogee

I myself had similar issues with my starter for a few months before I replaced it.

Depends how much driving you do.

If you trust your mechanic, then follow what they say I suppose. But I predict an expensive CAS replacement followed by a starter replacement after.


Diagnosing this problem is really simple and I'm surprised they haven't tried this.

1. Pull the intake plenum off (10 minutes)
2. Access starter solenoid control wire
3. Have someone cycle the start button and check for voltage on the signal wire at the starter.

If it fires everytime, it's the starter.

I drive the car daily. They mentioned since it was intermittent, the testing they want to do needs to be done while the car doesn't start. They said that once the car fires up, all testing done while the car is in working condition won't matter since the car thinks it's fine. So they want me to drop the car off for a day so they can replicate the problem. I'm going to take it to another shop locally here just to get a second opinion. I'd actually be happy if it was the CAS as the replacement is easy and part is similar in price. The starter replacement seems dreadful lol

[WingZeroX5]

Originally Posted by codinge90

I drive the car daily. They mentioned since it was intermittent, the testing they want to do needs to be done while the car doesn't start. They said that once the car fires up, all testing done while the car is in working condition won't matter since the car thinks it's fine. So they want me to drop the car off for a day so they can replicate the problem. I'm going to take it to another shop locally here just to get a second opinion. I'd actually be happy if it was the CAS as the replacement is easy and part is similar in price. The starter replacement seems dreadful lol

The starter replacement is fairly straightforward. The most difficult thing is moving the harness out the way.

[codinge90]

Bump

[codinge90]

Bump

[WingZeroX5]

If you trust your mechanic, then go replace the CAS and report back. I bet that won't solve your problem, because I had to press the start/stop like 50x before it got to start too.

[jpE92M3]

I’m having almost the exact same issue. So OP did you end up replacing the CAS or was it the starter?

[codinge90]

Originally Posted by jpE92M3

I’m having almost the exact same issue. So OP did you end up replacing the CAS or was it the starter?

It was the starter. Majority of the time it's the starter.

[BRNDNSLVRA]

Having the same issue. I actually replaced my CAS w/ one from a crashed car back in August 2022. Everything has been fine until this last week. Car would take 2 clicks of the start button to start up. Finally today the car just didn't start up at all. Tried resetting the battery and jump starting. Nothing worked.

Scanned the car and saw A0C1. Searched online and found this thread so Im ordered a starter and Im gonna replace it. Hopefully that solves it cause if I have another CAS issue Im gonna lose it. BMW discontinued the part which is bullsh*t. Luckily there are services out there that can fix it.

[M_Torx]

had start problem wasn't going to deal with it until spring... 💯 was engine ground must be completely cooked started right up with booster cables on engine and chassis