Hello MINI friends!

I'm writing this in the hopes that someone will find this helpful. To save some of you the time, I'll give a TL;DR version upfront. I fried my car access system (CAS) module overnight after leaving a Schwaben scan tool plugged into the OBDII port and my car wouldn't start.

Now for the full story. I own a MINI R56 "justa" named Herbie with almost 150k miles on it at this point. Herbie has undergone a timing chain and guide replacement, and as of recent, a clutch kit and water pump replacement. These things didn't NEED replaced, but were more of a choice to keep Herbie running smooth. The original clutch wasn't terrible... it would just jump and chatter little starting off from a stop. Anyways, I had finished the clutch and water pump job with little to no issues and took Herbie for a drive. Everything was perfect. To make sure the water pump was working properly and not air locked or anything, I plugged in the Schwaben by Foxwell Pro Scan Tool that my father bought from ECS Tuning. I was watching the coolant temps as I was driving to see if the thermostat was opening when hot, and as expected, it was working. So far so good. We extensively checked the car after rebuild and right before driving it.

It was a long day of work and I parked Herbie in the garage, went inside, and promptly crashed for the night. The next morning I go out to start Herbie and the battery was dead. Mind you, it was the original battery from 2011, so it was due for a new one anyway. New battery in, registered the battery with the scan tool, all fine and dandy. When I press the start button... RUHH... that is all I hear. Just a single second of starter engagement and nothing else. This was shown in a separate thread on NAM and it is exactly what I had. The car at this point is also showing as many fault codes as I can imagine and one in particular would not clear. "A0C1 - Present - Output - Terminal 50E". After much research, I had learned that the terminal resides in the CAS module under the dash, right behind the tachometer. It apparently communicates to the ECU during start up and if there is a communication mismatch with that and the flywheel speed, it stops the startup sequence (anyone who knows more, please correct me on this if I'm wrong). I was reading the voltage at Terminal 50 during the startup attempts and it consistently read 0 Volts. Fast forward to tear down, my father had removed the CAS (I had gone back home since I had to work the next week) and was given quite a surprise as seen in the photos.


Here is the CAS module, looking through the windshield



Also note the burn mark on the side of the white relay. It must've gotten pretty hot..

The little black component beside the giant white relay was toasted. It also smelled incredibly strong when the dash was opened up, according to my father. After this we were 100% positive we needed to replace the CAS, since we were thinking of everything from the starter to the clutch switch. RPM Motorsport in Victoria, BC specializes in BMW and MINI DME and CAS programming. They were OUTSTANDING with their customer service and helped get us a new, reprogrammed CAS in under a week (counting shipping, and UPS losing our CAS and keys once). Only paying a little over $500 was way better than the typical ~$2000 fix from a MINI dealer, and they even programmed my keys with the new CAS.


New, shiny, unburnt CAS

After receiving the new CAS, we plugged it in, reassembled the dash, and it started up. It blows my mind that one small chip on a board can immobilize a car like that, but I suppose that is how the modern automobile is built now. Just like a computer on wheels!

Lessons learned: After some deep reading into BMW and MINI CAS modules, I have found a few places that very specifically mention having a constant 12 Volt power supply on the vehicle during ANY programming, coding, or diagnostics to maintain sufficient power to the electrical systems, or adverse effects may occur. I've done plenty of work on cars, but never really had much thought into that. I especially didn't think any sort of low voltage event like a dying battery or a scan tool would cause anything like a dead CAS. Maybe the scanner didn't actually do it? Maybe it was just old? I would love any comments. The more discussion, the better.

Either way, I really wanted to make this thread for anyone who ever will or has encountered this issue. I spent more time digging through BMW and MINI threads than I want to admit. I even called a few MINI specialist mechanics desperately asking if they've dealt with the startup problem. I'm incredibly pleased with RPM Motorsport for their amazing work and help. I also don't write any of this to discredit the Schwaben scan tool or ECS Tuning. None of that. Without the Schwaben, I wouldn't have been able to read voltage over Terminal 50 and figure out it was the CAS module! Simply user error and fault for leaving it plugged in overnight.

To end, I hope some of you, if only just one person, find this helpful. This ordeal made me quite unhappy, but I am happy to learn from it.
Happy Motoring, friends!


Herbie in her prime. Back on the road and running like nothing ever happened!

 

Thanks for posting. Very well documented and informative thread. BMW, and consequently MINI, have made something as simple as a battery replacement a perilous task. On the BMW side, for some models, it's the FRM that is very subject to frying when replacing the battery.

Now go have some fun in the snow with a refreshed Herbie.

 

Hello, I have the same issue but 2 codes A0A9 CAS Control module fault and A0C1 Output - Terminal 50E. Starter was already replaced and I verified that is not getting 12V to the solenoid when trying to crank. It does not even engage at all for a second. When pressing the button it is silent. The customer has 2 keys. Both of them no crank but one does not even turn the ignition on. Supposedly the 2nd key was programmed to the car by some mail in service but never worked. I thought it is wiring or programming problem (related to the 2nd key) but found this post when searching for 'A0C1 Output - Terminal 50E' code. This is my customer's car not mine. I have a question to the OP. Did the car have ignition (key ON) or not and 'A0C1 Output - Terminal 50E' was the only code? Asking because it takes some time to remove the CAS on these.

Thanks, Al.

 

Al,

I'll start off by saying I hope you find a solution. This CAS issue I had was the biggest headache I've ever had with a car. If I'm not able to help enough, definitely search these codes on BMW forums. They use similar, if not the same CAS modules on some models. As a last resort, contact RPM Motorsport https://www.rpmmotorsport.net/ for help. They're customer service over the phone was fantastic and they were able to confirm my suspicions during our first conversation, and fix the CAS within a weeks time shipped back to me.

To begin answering some of your questions, I only had A0C1 - Output Terminal 50E as a visible code. It showed as duplicates on the scanner because I think it was reading through different modules. As for having the car ignition in "ON" or not, I had the key in, depressed the clutch, and tried to start it like normal. I read the codes after every failed start without removing the key.

The A0A9 CAS Control module fault seems to be different and may be causing the lack of starter engagement? A bad key will also cause no crank, and if I recall correctly, it should show a key icon on the tach display if it isn't coded to the car properly. My starter would engage, but only for a split second. I, too, was not getting 12V to the starter, so I'm pretty certain that is A0C1 related. Check the link here http://www.micro-tronik.com/learning...ain-functions/ to learn what Terminal 50E does. 50E carries a signal (this is the 50E output) from the ECU to the engine to start, and waits for a return signal (50E input) that says the engine is now running. As you could see from my pictures earlier in the post, 50E was fried and there was no signal output to be read.

Some other ideas that may be completely unrelated but would save you time from starting to rip out the CAS, would be to check the starter relays and check to see if the battery was "registered" to the car (I learned that this was a thing, some MINIs require new batteries to be registered to the ECU). Not sure which program/scanner/tool you are using and what capabilities you have. If I had to make a guess, there is probably a terminal (or two) internally that is disconnected within the CAS or toasted like mine was. Especially if you are receiving the A0C1 Terminal 50E code, that is for sure the component that fried on my CAS.

I'll try and keep digging around and I'll post a reply to you again if I find anything.

Good luck! I hope this helped some.

-Kodey

 

Thank you for taking the time to answer. I already talked to RPM. They quoted me $560. I cannot justify this price. New CAS is $100 cheaper and at least you know it is new. Plus they are in Canada, I would have to ship the items over the border, deal with customs, wait, etc.

Let me elaborate a bit on the situation. I'm an auto tech and deal with these issues all the time. So, replacing the CAS is not a big deal for me. This particular vehicle belongs to a friend of mine and a customer at the same time. He is a used car dealer and fixes many issues himself giving me the "headaches" . I don't mind as he helps me a lot too, steering a steady stream of customers my way and giving me an access to car auctions if I need to buy a car. In any case, I owe him a few favors and have to fix this car as cheap as possible. In any other case I would just buy a new CAS without worrying too much. They come programmed with the correct ISN and key data. I bought them before. This one here, my cost is about $460. The customer knows that as he gets the same price from the dealer. So, you see right here, there is no way I can offer him the RPM deal which is $100 more than a new CAS.

Now if I only had the A0C1 code, I'd buy a new CAS but the A0A9 code worries me as whoever programmed the keys might have changed the key and other data and now the new , original CAS and these keys that the customer has will not work . These codes will not clear. That is why I was so interested if you had the A0A9 code too. I'm trying to find a solution when someone would provide the CAS and check / program the 2 existing keys that I have at a better price. I already checked a few places but some people did not get back to me yet. There is a lot of people doing that, apparently but who knows how reliable they are. I'll find a solution for sure and let you know of course.

BTW, I took the CAS out, since it will have to be send for repair / programming anyway and it has the burn it more less the same spot. Seems it is a common problem with these. I'm guessing that white relay is a starter relay and the burned trace is for starter solenoid. So, you might have a marginal starter in your car. Remember they already replace the starter on mine.Regards, Al.

 

Just a quick update. After researching all options I decided to go with this service: BMW and MINI / All Models / All Years / CAS 1 CAS 2 CAS 3 CAS 4 / Cloning Service / Plug n' Drive. They have a Plug n' Play CAS for $395 but the guy said the cheapest way is to clone my CAS to a good used one. Found on on eBay for $40 shipped. This service is $215, key programming is free and it doesn't matter if the keys are new or used, even from another car. They will make it work, they said. They also give free shipping label to ship items to them. So, it looks like I'll be all set for $270. $200 less than new CAS.

I'll keep you posted, Al.

 

Sorry, for late reply. The car is fixed and gone. Customer happy and I'm happy. I got the CAS and keys back in 2 days. Car started right away, no code A0A9 CAS Control module fault or A0C1 Output - Terminal 50E. Both keys work (remotes too) and they even cut the blade on aftermarket eBay key. At $215 I find this a great value. I have to say that after I sent my CAS, I found another similar service at only $200 called bimerscan (Google). They seem to be doing the same thing but there was no key programming. So, you might try them as well. Below pictures of CAS and keys.Thanks, especially to kodeyedwardjones.

 

I have a 2009 Mini Cooper and when it’s really hot outside, No start, clicking noise from passenger side fuse box. It’s definitely the CAS module because sun is hitting right at the dash where the CAS is. I have sent my CAS module to RPM Motorsports already. Did you get your old CAS module repaired or completely replaced with a remanufactured one? They quoted me an extra $200 to get the CAs module completely replaced with a remanufactured one after finding no issues with my old CAS module.

 

I'm surprised nothing was found with your old CAS, but yeah I had to replace mine entirely. I sent in my keys and old CAS so they could mimic my current one and program the keys to the new one. Did RPM give any idea as to why the CAS was fine but you were having no start issues? As someone stated above, the FRM or footwell module also is a source of electrical issues. Were all your starter relays/fuses still good?
-Kodey

 

Living in Southern California, during the summer, I have the no start issue only when it’s hot outside ( sun hitting the dash ). But during the winter or any other season. Starts up just fine and everything works. Definitely can’t be the FRM module because all the dash lights, interior lights, and windows work fine. I’m thinking of just replacing it with a new CAS Module like you did for $800. New is better than old right? Lol. Fuses look all good as well. I appreciate your input friend!

 

Hello,

I know this thread is a little old but I am having the same issue with my CAS, I sent it out once and they found no issue but it still clicks from the fuse box and has issues starting.
Did you go with a clone ? Someone really need to start a class action las suit.

Scott

 

Word of caution - if you've been working on your engine and seeing a no-start situation where the starter won't crank, don't immediately assume it's the CAS. It very well could be, especially if you smell burnt electronics in the dash area above the cluster. But it could also be wiring related - grounds, the Terminal 50 white wire in the engine bay starting in front of the battery, or water damage corroding terminal in the pass side junction box.. Trace your steps before assuming the worst.

Here's a great Terminal 50 wiring troubleshooting vid
Another great vid to troubleshoot crank but no start - again not the CAS
I had A0C1 and AOC2 faults on our 2011 countryman, no crank on the starter. Turned out I didn't tighten the right side motor mount ground bolt when I reassembled it. Tell-tale sign is it changed behavior - it started up fine initially, next day I had the key symbol pop up but would still start (with horn blaring each time I tried), and then it eventually settled into the AOC1 AOC2 no crank situation that forced me to actually troubleshoot the wiring and find the root cause. I still need to get the key/CAS re-coded so I can reconnect the horn.

May others reading this have problems like this as well then being forced to spent big bucks and effort to tear your dash apart to replace the CAS.

 

Can you tell me if you cured this problem and how?

 

Hi Guys, did a new CAS cure the heat problem?

 

Can you tell me what you did to cure the hot day problem please? It's started doing that on my Mini R56 2008

 

My 2011 mini cooper s has been having troubles recently like randomly dying on the road, windsheild wipers coming on when the car dies, and im not able to get the key out of the slide. a week before all of these problems i installed an aftermarket radio and i have an ultragauge pulled in all the time, but the isssues only started a week after the radio was put in. it was extremely hot that day and i havent got a chance to check the CAS. also when i disconnected the battery to turn the windsheild wipers off i reconnected it and the relay2 in the passenger side fuse box started clicking like crazy and my head lights came on and wouldnt turn off. my steering wheel combo switch is bad so the parking brake and the dsc light on my tach are yellow but would that casue all this?

 

Hi Everyone,

I took the car to a mini specialist and he diagnosed CAS module fault. Changed the CAS and no more problems

 

took mine apart and ta da. Above the white relay.

 

Brilliant! well done mate