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2002-2010 E53 x5 E60 E63 E64 E65 E66 Intermittent Crank Issue Solved

2002-2008 E53 x5 E60 E63 E64 E65 E66 Intermittent Crank Issue Solved

Part Number: 12.52 7 510 638


Carol called to tell me she was having starting problems with her 2008 750Li. We set up an appointment so that I could inspect it. The starting problem was intermittent and we couldn’t be replicated it on demand, so she decided to leave it with me. It took a couple of days before the no start problem happened again. I scanned the car to see if there was a fault was being registered. Nothing was coming up indicating everything in the car was ok. Since there was no fault to go by, the only thing that occurred to me was to find out what relay or module was responsible for operating the starter. At the moment, I regret that I could not figure it out. She picked up her BMW days later.

Several months had passed when I experienced the same issue with my personal 2005 750Li. I stumbled across a YouTube video that mentioned a module I’ve seen before but hadn’t made the connection with the problem. The module is called the Integrated Supply Module (ISM) located by the DME (Engine Computer). After opening it up I found out that it has a series of relays that operate the starter. Curious to see if one of the relays was the problem, I started removing the casings looking for signs of wear. I found that one of the middle relays had darker contact points with carbon build-up. If these relays were serviceable, I could’ve taken the relay out to clean it. But since it’s not, I decided to buy another module and see if it would fix my car.

I knew that this part was just a simple module made of relays and resistors that would require no coding or programming at all, regardless of what BMW would say. So I called them up to order the part. That same day I replaced it in my car and solved the mysterious starting problem completely.

The same customer happened to call me again, asking me if I had learned anything knew before she took it to BMW to get it fixed. She had been quoted $1,500 between diagnosis, parts, installation, and programming. I told her that I had just experienced this exact same issue with my personal car and told her to bring it in. We replaced it the next day and I’m happy to report her BMW has also been fixed saving her a total of $1,220 she can take to the bank.


Does your BMW have trouble starting let alone cranking at times ? Does it click at first, but not turn over and start? Does it randomly shut off while driving?

I have even seen sluggish performance under 4k RPM and the occasional P R N D Lights Flash which will cause your car not to crank as well.


 If so, your Integrated Supply Module (ISM) may be the problem. As these BMW’s continue to get older, this issue is becoming more and more common. It might even get to the point where the car doesn’t even start at all. Below you’ll find pictures to help you locate and replace it the part yourself. You can purchase this module directly from us by clicking here or on the image below. You can also call me if you have any questions or concerns. Tomas at (951) 522-4032


X5 E53 4.4i 4.8i 2004-2006

5 Series E60 E61 545i 550i M5 2004-2010

6 Series E63 E64 645ci 650i M6 2004-2010

7 Series E65 E66 745i 745li 750i 750li 760i 760li Alpina B7 2002-2008




Check underneath the passenger cabin filter.


Lift the plastic cover.


This is where the ISM is located.


Start unplugging and remove the old ISM.


Insert the new ISM module.

Make sure all plugs are connected properly.


Secure ISM in its proper location.


Installation is Complete.






19 thoughts on “2002-2010 E53 x5 E60 E63 E64 E65 E66 Intermittent Crank Issue Solved

  1. WOW just what I was searching for. Came here by searching for BMW Intermitted Crank Issue

    1. Thankyou very much for such a detailed explanations. I had same problem with my 750 like 2008 for long time and took it numbers of times to BMW dealers in Florida and Texss. Answers were typically dealers answers. We have to see it and you may leave the car. It may be starter, battery electronic, or programming.
      I ordered the ISM after read your explanation, got it and replaced the ISM. Everything turned OK and no more problem.
      I may add that strangely when you read about ISM in BMW documentation about ISM it clearly refers to this problem of intermitting starts or some jerking in transmission and I had both but how dealers do not know this and/or pretend they do not know. Module cost me $110 and I also took the opportunity to replace microfilmed that dealer was asking $450 to replace. My cost for both filters $24
      Thank you again and again

  2. I really enjoy the forum.Thanks Again. Cool. Mclean

  3. The engine would stall the transmission would shift hard or erratically. I replaced the Mass air flow sensor, the throttle position sensor the Idle air control sensor. This solved all the issues I was having. Thanks for all your help.

  4. I have a 2004 525i and my car will not start but all the lights, radio, a/c, doors lock/unlock, windows work but for some reason the car will not start. I thought it was the ISM so I purchased one from BMW dealer but my car did not have this ISM. Fortunately they refunded me for the ISM. Took the car to dealer and it was the starter so I purchased a new starter. In April I purchased a new battery. Everything was fine until September 2016 I am experiencing the same issue. The car will not start. Took it to the BMW dealer and they said it could be the DME but they are not sure exactly what is wrong because their system is stating there are 3 modules failed. One module could have failed and preventing the other 2 modules from being read. But they still can not find the root cause. They said it will take them longer to investigate further which will add another diagnostic fee before the car is even diagnosed. Can anyone suggest why this car will not start? Any advise will be helpful.

    1. These Starters are notorious for just quitting one day with no warning or second chances. Don’t EVER buy one of these starters from Auto Zone or Local stores that sell their own brand like Duralast, or online like eBay who claim them to be OEM for only $130.00. I am not kidding when I say they only last 6 months to 1 year. They have a lifetime warranty but who wants to change these every couple seasons? You have to buy the original BOSCH either remand or new. Spend a little extra -$280 instead of getting the $130 starters that fail consistently.
      If you bought a OEM or Bosch unit then you could have a bad CAS module which I have seen fail on my own personal 2007 530xi. (My CAS went first, then my starter 4 months later). The CAS2 models fail and when you order a new one from BMW with your VIN and proof of ownership you will get a CAS3 so you know that it wont fail the same way again. Programming is needed for this, the car will start but you will have a Christmas tree of lights on.

  5. hello,
    I just recently bought a USED BMW 745LI with 159,682 miles on it from one of my customers that painstakingly has given up on it.I bought it pretty cheap.Anyway,the problem that its having is there is no codes in ecm when I connect my snap-on verus scanner up to it.The car cranks over slowly,I do not hear the fuel pump energize,and it simply will not start.Can you offer some insight to where I can start a good diagnosis or Just tell me what components deal with starting and power supply to the fuel pump.Any information would be great.

    1. To be honest I can’t tell you for sure but I have personally seen Four 7 Series lose the CAS—>DME Adaptation from having the battery disconnected for longer than a day, i.e. engine swap or valve stem seals repair. This will cause a no spark or fuel pump activation. There is also a fuel pump replay in the Passenger B Pillar that activates the fuel pump which goes bad too. This can be confirmed by externally powering the fuel pump and then cranking it. Hope this helps.

  6. does the integrated module has to reprogram after replacing a new one

    1. No not at all. This is just Relays and Fuses. If you open up your old one you will see. Dont let any Dealership pull your leg and tell you it needs 1-2 hours of programming to replace a relay/fuse pack.

  7. This is exactly my problem. The BMW dealer replaced my starter – $1521 – but I am still having trouble. this sounds too simple. Can I change this myself?

    1. Yeah it actually is this simple. I am sorry to hear that they jumped to the starter first thing. The Relay inside of this ISM activates the Starter amongst other things, so yeah it could very well be this. It will take you 15 mins to hook up if you have all the common tools.

  8. Hi
    How do you extract the ISM from a UK 760Li?
    After removing the 4 connectors from the top, you cannot then extract the ISM as there seems to be more connections underneath (which you can’t get to)

    Any ideas?

    At the moment, my car is flashing the PND lights when idling (the RPMs drop too when the lights flicker) and they flicker every time it’s revved hard.

    I have videos of the symptoms if you have time to email me 🙂

    I have tried a different Power Module (no change)
    I have ordered another SIM/ZGM (aka SGM) as I’ve seen issues with the iDrive being dead on entry and the Comfort Access being offline which requires a battery off/on reset..

    Perhaps this is the cause, but it sounds like it could be the ISM as I too experience a rough(ish) idle and the occasional no start..


  9. I am a do it your selfer kind of guy is people like yourself that average joes are not taking advantage off may God bless you and your good intentions I recently had my old 2002 745i stall on me with my kids in the middle of the busy freeway here in LA I love this cars but oh man they have so many issues, it did run again but before it gives me the same problem I am going to replace that part just in case

  10. I’m having the same issue it stalled on the free way and won’t start and is not giving any codes? I have changed the crankshaft sensor but still will not start. 2006 x5 4.4

  11. I don’t ordinarily comment but I gotta admit appreciate it for the post on this special one : D.

  12. I had a 2005 545i with the same issue. It would fail to start intermittently, one time it hesitated on the freeway which almost got me in serious trouble. My very good mechanic figured the problem but it did take him some time.
    Thank you for sharing this information

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