Car is "waking up" every 1min 15sec, draining battery. CAS issue?

[turbodriven]

Bought a 2011 128i (Auto, N51, with 77k) a month ago from a dealer that had just had a new battery installed. Dealership (says) it got it from auction with a dead battery and from what I can gather, used it daily until they sold it to me. Battery was registered though when they replaced it.

When I drive it every day it's fine. But after 48 hours it'll drain past the point of starting. I did all the standard parasitic drain tests until I figured out that my car has comfort access, and that it's not working. Remote buttons work to open doors, and with the key in the ignition hole the car starts. But none of the handles unlock with the key in my pocket. Interestingly, even with all the doors unlocked using the key fob, the trunk switch on the trunk still doesn't work (but the physical switch is tested as good). All other ways to open the trunk work (except with key in pocket obv.).

Anyways, pulling up INPA it shows that my (only) key is key #2. Just to mention, I tried some thing I read about where you hold the lock/unlock button on the center dash plus the start/stop button and using that to "re-learn" the key. But it had no effect. Battery in remote is at 3.0v on multimeter so I assume it's good.

So here's what happens. The car goes to sleep after 20 or so minutes in that the light at the Park Selector goes out. But then every 1min, 15sec the mph/tach needles twitch momentarily, and the start button illuminates for 15 seconds and then goes out again. Park selector light stays off during all this. But the car draws 1.45 amps while it happens. Otherwise it's pulling .34 amps (still too high).

So I'm thinking that something is not working right with the CAS. And it's causing this "wake up" cycle. But I have no idea what to do outside of an expensive dealership visit. I replaced the Passive go module in the trunk, thinking it got wet at some point and fried, but no change. It was cheap, but I did this before I really started understanding the problem or the car.

I cleared all the module codes in INPA, and then re-read them 48 hours later after driving 100 miles. See the attached sheet with what codes are popping up. Ignore the TPMS stuff (I think), my aftermarket wheels don't have sensors in them.

[turbodriven]

Does anyone know how to use INPA (or whatever) to test individual door sensors and CAS antennas, etc. I know you can, I just don't know how.

[nazali]

following Turbo

[nazali]

dude you got the same problem as me, although, my battery is being drained to dead

[nazali]

reading your post, we have the same issue except for the following

1> my battery does not die
2> My CA works, for boot and start stop (i.e. key in packet)
3> I have a convertible and the fob opens and closes
4> I was going to change the CA module in the trunk, but didn't yet

I use ISTA, I can get you some screen grabs of what you can check

you should be able to check

1> The battery charge over 5 days
2> The battery % charge
3> Current drain, how often the current is over 80ma
4> How many times the car is being woken up
5> You can test the door handles
6> You can test the wireless modules

In our cars, there is 4 or 5 wireless modules

1> 1 in each door handle
2> 1 in the boot
3> 1 in the inside of the car (middle I think near the center console)
4> 1 in the front by the windscreen

Have uploaded a PDF for comfort access

let me know if you have ISTA, and I can walk you through

[nazali]

My CA passenger stopped working after a 3rd party windscreen repair was a total bodge, I suspect water egress and a damaged module,

windscreen was howling, but I managed to fix it, probably after the damage is done

[nazali]

OH did you restart the CAS module ?

After working on the CA, and replacing, you need to restart the CAS ?

That PDF says so as well.

I was too scared to restart mine, as I didnt want to have a worse day !!!

[turbodriven]

Originally Posted by nazali

let me know if you have ISTA, and I can walk you through

Thanks for the PDF. It'll give me some overall knowledge of what I'm working with.

All I have are the BMW Tools. INPA, NCS Dummy and Expert, Tool32. Etc.

Where can I get ISTA? Is it free like the BMW Tools? If I can get my hands on it, some direction on how to use it to test will be invaluable!

[asbrr]

This may be a dumb question - but have you checked the CAS module for water damage? Can be quite common. My CA stopped working and the car would do insane things with the dash until I found the water damaged module.

[iminhell1]

ISTA-D is a substantially larger download / program. I think it's easier to use though.

I think this is the one I used,,, I can't recall if there is a key or anything.
https://mega.nz/file/a1wUmYCD#G0C3_H...o9uQ4EpxjI8oZs

[turbodriven]

Originally Posted by asbrr

This may be a dumb question - but have you checked the CAS module for water damage? Can be quite common. My CA stopped working and the car would do insane things with the dash until I found the water damaged module.

You're talking about the module behind the headlight switch?

I replaced the one in the right trunk, the passive go module, even though it looked clean. Aside from the missing warranty seal.

The one behind the headlight switch, I think is called the CAS module, it's black. But you can't just swap it out. It has to be programmed to your car. As I understand. Given it's location I don't know how it would get wet. Unless a sunroof drain failed maybe? That happened in my Durango once.

[nazali]

yeah that's common as well, I managed to pull my CAS module out, and take it apart, all looked ok, but again, I didnt wanna spend too much money plus it needs coding but good point

Originally Posted by asbrr

This may be a dumb question - but have you checked the CAS module for water damage? Can be quite common. My CA stopped working and the car would do insane things with the dash until I found the water damaged module.

[nazali]

The trunk module is the CA Module (comfort Access) and looks after all of the CA, that doesnt need to be coded. (looks after CA doors, boot, and yes keyless start and all that gubbins)

Yes behind the headlight is the CAS, and needs to be coded, but it is easy for it to see water leaks, would be worth to check it, I did mind, but wether a visual check is good enough.

In Ista you can restart modules, I'm hessitant to restart the CAS

I restarted the CA module though

Originally Posted by turbodriven

You're talking about the module behind the headlight switch?

I replaced the one in the right trunk, the passive go module, even though it looked clean. Aside from the missing warranty seal.

The one behind the headlight switch, I think is called the CAS module, it's black. But you can't just swap it out. It has to be programmed to your car. As I understand. Given it's location I don't know how it would get wet. Unless a sunroof drain failed maybe? That happened in my Durango once.

[nazali]

My mate loaded up all the BMW software, it's be reingold, it's "hmm" not officially released by BMW and you can get uploads,

if for sure you do, I can give you some screenshots

when I was trouble shooting I used it to find were the fault is

Originally Posted by turbodriven

Thanks for the PDF. It'll give me some overall knowledge of what I'm working with.

All I have are the BMW Tools. INPA, NCS Dummy and Expert, Tool32. Etc.

Where can I get ISTA? Is it free like the BMW Tools? If I can get my hands on it, some direction on how to use it to test will be invaluable!

[nazali]

turbodriven, PM sent BTW

sent you a link

[turbodriven]

Originally Posted by nazali

The trunk module is the CA Module (comfort Access) and looks after all of the CA, that doesnt need to be coded. (looks after CA doors, boot, and yes keyless start and all that gubbins)

Yes behind the headlight is the CAS, and needs to be coded, but it is easy for it to see water leaks, would be worth to check it, I did mind, but wether a visual check is good enough.

In Ista you can restart modules, I'm hessitant to restart the CAS

I restarted the CA module though

The one in the trunk is labeled "Passive Go". Which if taken literally, by definition, it is the system that allows you to "go" or start the car with your key in your pocket. I thought that was all it really controlled? With this car though, who knows. I'm going to use that link you gave yesterday to download ISTA and hopefully get that running. I have a feeling it's a lot more "usable" of a program than the INPA I've used so far. If I can check modules, antennas, and sensors individually, and then "reset" modules too. I feel like that'll at least get me farther down the road in this hunt.

[asbrr]

Originally Posted by turbodriven

You're talking about the module behind the headlight switch?

I replaced the one in the right trunk, the passive go module, even though it looked clean. Aside from the missing warranty seal.

The one behind the headlight switch, I think is called the CAS module, it's black. But you can't just swap it out. It has to be programmed to your car. As I understand. Given it's location I don't know how it would get wet. Unless a sunroof drain failed maybe? That happened in my Durango once.

Sorry - you're right, I meant the CA / comfort access module not the CAS module!!

[turbodriven]

Originally Posted by asbrr

Sorry - you're right, I meant the CA / comfort access module not the CAS module!!

Yeah, so then yes I did replace that. Seeing that it was a new car to me I didn't know the history. So I thought it may have gotten wet at some point (after hearing others stories) and fried without any obvious visual damage. I also thought it was weird that it didn't have the warranty seal on it. And that I was hearing a relay clicking noise coming out of it every minute too. But after replacing it with a known good one, there was no change in behavior. I have not "reset" it yet though. Might try that soon if I can figure out how. Can't hurt.

Also note, that I'm not pulling any error codes for the CAS. INPA always says "job status OKAY" for that module. I am pulling an A0A7 code in the PGS module though (passive go system). Despite it being a good module. Nothing pulls up as a description on that code when searching BMW fault codes. But I found somewhere where it was called a "TAGE_BFT_WUP_no_response" error. Tage is the door handles I think, not sure what BFT is, but WUP is "wake up"?? and No response is obvious.

That's why I want to test the door handles.

Edit: I just discovered that BFT is "passenger front door". So my CA module error code is "Passenger front door module, wake up, no response". If I can test and confirm it's bad, maybe I just found my problem. Maybe. I wonder if "disconnecting" that module will cause my sleep issues to go away? Or just create more errors?
https://static.nhtsa.gov/odi/tsbs/20...43566-9999.pdf

[MightyMouseTech]

Usually it is one the handles that goes out first. 10 min job to pull off the outer handles, disconnect the two connectors going to the handles and see if that fixes the battery drain issue.

Often when a handle shorts out, it will be warmer than the other handle as well.

[turbodriven]

Originally Posted by MightyMouseTech

Usually it is one the handles that goes out first. 10 min job to pull off the outer handles, disconnect the two connectors going to the handles and see if that fixes the battery drain issue.

Often when a handle shorts out, it will be warmer than the other handle as well.

So I've heard. This is a northern car too (New York for most of it's 77k life). It's in Florida now. We just always hear horror stories about northern cars. Who knows. I'll watch a tutorial on how to remove the door handle and see where that takes me. Fingers crossed.

[nazali]

Yeah it's called the "passive Go, comfort access module" it basically does everything to do with the CA before it hits the CAS module,

Originally Posted by turbodriven

The one in the trunk is labeled "Passive Go". Which if taken literally, by definition, it is the system that allows you to "go" or start the car with your key in your pocket. I thought that was all it really controlled? With this car though, who knows. I'm going to use that link you gave yesterday to download ISTA and hopefully get that running. I have a feeling it's a lot more "usable" of a program than the INPA I've used so far. If I can check modules, antennas, and sensors individually, and then "reset" modules too. I feel like that'll at least get me farther down the road in this hunt.

[nazali]

yes, that sounds like a good bet, the pas handle, in my case I can't spend $500 for a new one, the handles can't be painted and are special order from BMW, UNLESS you get one the right color of ebay, they start around $75

I was thinking of doing that for a test.

I have INPA, dont really used it LOL.

Originally Posted by turbodriven

Yeah, so then yes I did replace that. Seeing that it was a new car to me I didn't know the history. So I thought it may have gotten wet at some point (after hearing others stories) and fried without any obvious visual damage. I also thought it was weird that it didn't have the warranty seal on it. And that I was hearing a relay clicking noise coming out of it every minute too. But after replacing it with a known good one, there was no change in behavior. I have not "reset" it yet though. Might try that soon if I can figure out how. Can't hurt.

Also note, that I'm not pulling any error codes for the CAS. INPA always says "job status OKAY" for that module. I am pulling an A0A7 code in the PGS module though (passive go system). Despite it being a good module. Nothing pulls up as a description on that code when searching BMW fault codes. But I found somewhere where it was called a "TAGE_BFT_WUP_no_response" error. Tage is the door handles I think, not sure what BFT is, but WUP is "wake up"?? and No response is obvious.

That's why I want to test the door handles.

Edit: I just discovered that BFT is "passenger front door". So my CA module error code is "Passenger front door module, wake up, no response". If I can test and confirm it's bad, maybe I just found my problem. Maybe. I wonder if "disconnecting" that module will cause my sleep issues to go away? Or just create more errors?
https://static.nhtsa.gov/odi/tsbs/20...43566-9999.pdf