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Discussion Starter #1
The car is a 2007 3.0d X5 with 104,000 miles.

The problem....

Up until yesterday inserting the key in its slot lit the dashboard and then a quick press of the start button and away you go. All of a sudden - nothing. Insert the key in the slot and nothing.

While waiting for recovery yesterday evening I found a thread on here questioning failure of the CAS. It wasn’t exactly the same story however during the discussion reference was made to holding the start button for 10 seconds. I tried it and the dash came to life - hold brake, quick press of start and hey presto! Recovery cancelled and I got the car home. The question is - what’s changed? Sadly the thread I found went no further so, other than the hint re 10 seconds I got no other info.

I have INSTA d so have investigated codes and modules and nothing is reporting - the board is green. My wife had the car yesterday and she’s not used to the key slot convention of “press it in to take it out” - she forgot and, true to form, the key doesn’t lock into the slot as it did but that shouldn’t affect the starting sequence. I haven’t searched the forum deeply so I accept there may already be information but if someone could help, or even point me at another thread that would be great!

Ps the only reason I haven’t searched so deeply is I’m in the middle of rebuilding the vanos on my wife’s 330ci (hence she was driving my car) and that’s taking most of my time.
 

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When my battery started to die on my E70, in had similar symptoms as you're experiencing now. Just an FYI in case

Sent from my SM-N960U using Tapatalk
 

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Discussion Starter #3
Cheers for the thought. I have experienced weird error messages when the battery starts to die but this is totally consistent. When I put the fob in the slot nothing happens. If I put my foot on the brake and hold the start button after 8 seconds the handbrake warning and airbag lights illuminate and then 2-3 seconds later the dash lights up as it should and the car starts.
Similarly when I come to switch it off having pressed the start/stop once to shut the engine off if I press it again with my foot on the brake the car will restart - even if I’ve removed the fob from the slot (and just to clarify - I do not have comfort access).

It seems to be some sort of emergency start sequence but I don’t know what condition would activate this starting protocol.

Thanks for the thought though and I will double check with a second battery - just in case
 

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There have been some reports of the key fob not sitting right in the holder. Like it wouldn't stay in or couldn't come out or similar. Perhaps that's an issue? You might be able to surf and find a thread or two on the topic.
 

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Discussion Starter #5
Hi and thanks for the response.

I did some reading around but from what I understand provided the***8221;key***8221; is sitting in the slot then it should be read fine. Also if the problem was related to not reading the key I***8217;m sure the car wouldn***8217;t start at all rather than this peculiar 10 second thing.

I appreciate that what I***8217;m describing sounds really quite weird so I***8217;m going to make a video of it tomorrow and see if I can post it.
 

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Cheers for the thought. I have experienced weird error messages when the battery starts to die but this is totally consistent. When I put the fob in the slot nothing happens. If I put my foot on the brake and hold the start button after 8 seconds the handbrake warning and airbag lights illuminate and then 2-3 seconds later the dash lights up as it should and the car starts.

Similarly when I come to switch it off having pressed the start/stop once to shut the engine off if I press it again with my foot on the brake the car will restart - even if I’ve removed the fob from the slot (and just to clarify - I do not have comfort access).



It seems to be some sort of emergency start sequence but I don’t know what condition would activate this starting protocol.



Thanks for the thought though and I will double check with a second battery - just in case
It gradually took longer and longer to start until it wouldn't...
Good luck!

Sent from my SM-N960U using Tapatalk
 

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Discussion Starter #9
Twh, cheers for the heads up, I***8217;ll have a read. I was hoping someone could point me toward something like that ***55357;***56397;

320kplus, so have you experienced the same starting pattern as I currently have, do I take it that your car died and did you manage to sort it? I had thought, after finding it mentioned in another post, plus the fact that it has so far always been 10 seconds, indicated that it was some sort of alternative starting protocol. I wasn***8217;t expecting it to deteriorate. I***8217;ll have a read of the doc that twh has pointed me to and share further thoughts........ cheers for your input
 

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I can explain the 10 second thing...BMW has used that interval since the introduction of EWS II. The EWS system (now CAS and whatever acronym BMW uses for the immobilization/starting systems)...there is a 10 second window/interval where the identification of the secret key (or ISN...aka individual serial number) isn't required to restart the car. In the old gen BMWs with a key with metal blade...if a 2nd remote didn't work...if you started then shut the engine down with a working key...you could still start the car with the non-working remote if you used it within that 10 second period. In the new gen BMWs with the new remotes that are inserted into a slot...or the ones with comfort access...you can start those cars without the remote fob if you do so within 10 seconds of shutting the vehicle down with a working remote.

I can only assume that this was engineered for a quick restart when a driver may shut the engine off...but then realize or remember something that requires them to quickly restart the car (like I forgot to pick up a loaf a bread and a gallon of milk :) )...where EWS/CAS wouldn't need the requirement of processing the coded info between all the components of the system.

You can see the info below highlighted in the red box from the EWS II data. If you click the link to the PDF for the e70 that was given in the post above...you'll probably find the same 10 seconds somewhere in all of that info, too...since BMW's design and engineering architecture usually doesn't stray to much from on the fundamental operating parameters.

 

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Discussion Starter #11
Hi QSilver7, thanks for your detailed response it explains part of what is going on perfectly. I made comment that I could remove the fob with the engine running and restart the car after switch off and that all fits perfectly with your explanation. Unfortunately it doesn***8217;t explain having to wait 10 seconds for the car to start from cold. I***8217;ve been through the pdf listed above several times. I think, in tech speak, it makes some sort of mention of the provisions you describe but I***8217;m sure you***8217;re right in that regard so I can put that part of the puzzle to bed. Just need to understand the 10 second wait from cold now. It***8217;s been suggested that i can re-pair the cas and the ews so I***8217;m going to try that tomorrow and I***8217;ve ordered a new fob slot and it***8217;s ribbon - that should be here by the middle of next week.

I do think the 10 second wait is some sort of alternative or emergency start protocol as it***8217;s so precise and always the same. I just wish I could find out why the car needed to start using it.

Thanks again
 

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Discussion Starter #12
Firstly thanks to all that took the time to read my thread/watch the video, especially to all who offered ideas and solutions.

As with most things it often pays to rule out the cheapest solutions before throwing bucket loads at the problem and this rule has been proven once again.

As those who watched the video will have seen one of the symptoms (though not seemingly a significant one) was that the fob didn't appear to lock in the slot. As a second hand unit was only £30 with it's ribbon I figured I'd start by replacing it and guess what - it solved the whole problem! The fob locks in correctly and the car is back to starting on the button as it should! The cheapest solution paid off.

For further information having used the original ribbon (because I tested it and it worked with the new key slot) prior to throwing away the old slot I decided to test it. I put the fob in the slot - and it locked in correctly! Now I'm not saying the old key slot now works (I'm not about to take the car apart to test it again) but it's now locking the fob in place as it did prior to this whole episode. Just to be clear last Saturday I disconnected the battery for around 3 hrs and it made no difference but just maybe the cas (which is what the slot unit is connected to) has some form of long term battery support. Actually physically disconnecting the slot from the cas may have allowed it to reset so I may not even have needed to buy a replacement! I've only documented this in case at some point in the future someone else hits the same problem.

If anyone has problems anything like what are documented above then (having disconnected the battery) gain access to your cas and disconnect the ribbon that connects it to the fob slot. Try your fob in the slot - see if it locks correctly. Then reconnect the ribbon and your battery. Maybe this acts as a reset. Worth a try as it costs nothing beyond 30 mins of your time!
 
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