[ace2050]

BMW E90 318i 2006

As the title states I’ve had an intermittent no crank/no start for about a year by now. I’ve been trying to figure out the cause to no avail.

The car has usually started after a few failed attempts. I can only hear a click. Sometimes it would just click but then after like 2-4 seconds it would start.

Recently it has gotten worse until to the point it wouldn’t start at all. I checked the voltage of the battery after two days of it sitting in the parking lot and it showed 12.11V. The car turned on immediately with the help of a booster.

After that it has started but for example yeaterday after sitting for a day IT TOOK 20 ATTEMPTS… Today it started first try.

Replaced the battery and IBS about a year ago and the alternator a few months ago. Original battery was 90Ah and the new one 80Ah, but from what I understood this shouldn’t be a problem. Battery was also programmed and registered.

Pulled these codes from the car:
- 2E7C
- 2E8B
- 2EB8
- 2EBE

From what I understood these codes are saying something about the BSD-line? I’ve had problems with the oil sensor too which is connected to this BSD-line (sometimes it doesn’t work).

I’m begging for someone to help me I’ve been fighting this problem for way too long.

[ctuna]

https://www.youtube.com/@BMWDoctor

[Tambohamilton]

Sounds like the IBS is at fault. Though it could be another BSD device knocking out the bus. Try disconnecting the IBS and see if that helps the symptoms or the error codes.

[ace2050]

The IBS-sensor at negative cable was replaced a year ago but I will try to disconnect it and see if it helps.

[Bims328i]

Perhaps you have some corrosion or water ingress into the cars DME which could cause these strange issues. Ensure the engine bay / cowl box that contains the interconnects has not seen water intrusion and are not corroded.

I've thought it might be a good idea to place a silica pack in this box from time to time to absorb any moisture. I've been using them on my new headlamps to remove the tiny bits of residual moisture from the lamp assemblies.

[ace2050]

I thought that too so I checked out the DME but it looked ok, no water or moisture anywhere. I also checked the motors ground strap which was okay as well…

[Tambohamilton]

No crank no start is a known outcome of the IBS failing. No need to fuss about the dme. Follow what the fault codes tell you.

[ace2050]

But the IBS-sensor was replaced a year ago, do you recon it could be faulty from somewhere else than from the sensor?

[Tambohamilton]

The funny thing about the bsd line is that one faulty device on it can bring down the whole line. Start by unplugging the IBS. If that solves the no crank and clears your bsd errors, you know you have your culprit.

If unplugging the IBS doesn't help, recheck the error codes to see what has changed, then unplug the next device in the chain and recheck errors. Do this until you've singled out the failed device(s).

I assume you have already, but Google your fault codes - or better still look them up on ISTA - to get their proper definitions so you know what you're looking at. If you include this info in future posts, people can be more helpful too.

[ace2050]

I will try that, thanks for the advice. Also I did check the definitions of the fault codes but forgot to mention them in the original post, sorry about that. It is hard to locate the culprit since my problem is intermittent but I will try to see if anything changes in the fault codes. I will keep you updated!

[lookalikehuuh]

Let's be clear here, just because you have IBS codes doesn't mean its necessarily the IBS that is causing it.

The IBS, water pump, alternator, and oil level sensor all live on the BSD bus. If another sensor is failing it can cause all kinds of random errors from other sensors. What I would do is start by unplugging each sensor 1 at a time and then running the car to see if the codes go away with that component unplugged.

In my case I had a bad alternator that caused codes for IBS and oil level sensor, water pump worked fine though...

Then again, where did you source the "new" IBS from?

[ace2050]

I took my car to BMW service and they replaced the IBS there. You’re right on the fact that IBS fault code doesn’t necessarily mean that it’s faulty but rather some other component in the BSD-line. I have a coolant leak and an oil leak somewhere in the car too so it could be possible that the oil pan is leaking on the oil sensor or coolant leaking on the water pump maybe? I will spend tomorrow to investigate the BSD-line and update the results here. It can’t be the starter tho right? I think it’s the original one and the car has 180 000 kms but from what I understood these symptoms don’t add up to the starter being faulty…

[lookalikehuuh]

Originally Posted by ace2050

I took my car to BMW service and they replaced the IBS there. You’re right on the fact that IBS fault code doesn’t necessarily mean that it’s faulty but rather some other component in the BSD-line. I have a coolant leak and an oil leak somewhere in the car too so it could be possible that the oil pan is leaking on the oil sensor or coolant leaking on the water pump maybe? I will spend tomorrow to investigate the BSD-line and update the results here. It can’t be the starter tho right? I think it’s the original one and the car has 180 000 kms but from what I understood these symptoms don’t add up to the starter being faulty…

When starters fail there is usually a few failure modes, one of them is actually a "click" from the starters as it fails to properly actuate. It is definitely possible that the starter itself is failing as they do randomly fail. Although in my experience BMW starters generally fail from one day to the next, maybe your is just falling slowly but surely?

[ace2050]

Originally Posted by lookalikehuuh

When starters fail there is usually a few failure modes, one of them is actually a "click" from the starters as it fails to properly actuate. It is definitely possible that the starter itself is failing as they do randomly fail. Although in my experience BMW starters generally fail from one day to the next, maybe your is just falling slowly but surely?

But wouldn’t the fault codes be different if it were the starter? Also first the problem slowly got worse over time and the no crank/no start was becoming a more frequent problem, until it didn’t start at all and it sat for two days but with the help of a booster it finally started. After that it has been working well.. So if it is the starter it definetly would be a weird way for the original starter to fail

[lookalikehuuh]

Originally Posted by ace2050

But wouldn’t the fault codes be different if it were the starter? Also first the problem slowly got worse over time and the no crank/no start was becoming a more frequent problem, until it didn’t start at all and it sat for two days but with the help of a booster it finally started. After that it has been working well.. So if it is the starter it definetly would be a weird way for the original starter to fail

You don't always get a starter code when it fails... that being said I would figure out the BSD issue first, then figure out if the starter is the issue after that.

You should also check the grounds because its possible that you don't have a good ground therefore the starter doesn't have enough currently flow to spin up.

[ace2050]

Originally Posted by lookalikehuuh

You don't always get a starter code when it fails... that being said I would figure out the BSD issue first, then figure out if the starter is the issue after that.

You should also check the grounds because its possible that you don't have a good ground therefore the starter doesn't have enough currently flow to spin up.

Oh I didn’t know that, thanks for the information. I will check the starter if I don’t get problem solved by fixing the BSD-line. I’ve already checked the engine ground strap and it was in perfect condition but I will look more into that too!

[ace2050]

I was just about to leave to my parents to go do some investigation of the BSD-line but the car wouldn’t start. I immediately checked the battery voltage and it showed 12.3V which should be enough (I know optimal is 12.7V). I had another battery in my trunk and I tried to start the car with the help of that battery but it still wouldn’t start. That other batterys voltage was 12.4V. I also disconnected the IBS-sensor but that didn’t help either.

I attached a video of trying to start the car (ignore the airbag light it turned on a while ago due to reconnecting my battery and has not been cleared out yet). You can even hear the starter solenoid clicking under the hood.

Also when taking the key out the small screen on the dash didn’t turn off like it usually does, and earlier this week my lights stayed on after turning the car off and taking the key out. Only after locking the car doors remotely did the lights turn off?

I dunno why the car started with a booster a weeks ago when this same thing happened but now it won’t with the help of another battery. I put a charger on that battery now and will try again after two hours, I will keep you updated.

Watch the video here: https://youtube.com/shorts/iDFmi4GDx...ppsqZ2iY-vzhyE

[e92tincan]

ive never heard a good starter make that sound before. when in doubt, hammer it out, hit the starter and see if anything changes.

[ace2050]

Originally Posted by e92tincan

ive never heard a good starter make that sound before. when in doubt, hammer it out, hit the starter and see if anything changes.

I can’t get to the starter to hammer it out since it is under the intake manifold, thank you for the advice though. However I just tried to start the car after charging the battery to 12.60V but it wouldn’t start. This time though I could hear a strange fast crackling/clicking and weird electrical sounds from somewhere in the passanger side. I also made some research and it seems like my CAS module is going bad, that would explain the lights staying on after turning the car off too. The fault codes don’t add up though so i don’t know.

The starter being faulty is unlikely since it has been like that for almost a year and my understanding is that starters don’t go bad like that. It also is worse sometimes and better sometimes so there is no linear line of it going worse by time.

[e92tincan]

How do you lock and unlock the doors? With the key fob or the physical key? If its with the key fob then i dont think your issue is with the CAS module

[ace2050]

Originally Posted by e92tincan

How do you lock and unlock the doors? With the key fob or the physical key? If its with the key fob then i dont think your issue is with the CAS module

I use the keyfob but appearantly the CAS module doesn’t go bad overnight which would mean that my keyfob wouldn’t work at all but rather it is slowly going worse. I remember this one time I was leaving work and for some reason the red ELV light was on but went away after waiting for 30 mins. Faulty CAS module would explain that aswell.

I know i’m dumb as f*ck but I lost my license one and a half year ago and my car sat outside through winter for half a hear until I got my license back. It was getting moisture inside and thats probably how the CAS module went bad since it’s very sensitive.

[e92tincan]

Originally Posted by ace2050

I use the keyfob but appearantly the CAS module doesn’t go bad overnight which would mean that my keyfob wouldn’t work at all but rather it is slowly going worse. I remember this one time I was leaving work and for some reason the red ELV light was on but went away after waiting for 30 mins. Faulty CAS module would explain that aswell.

I know i’m dumb as f*ck but I lost my license one and a half year ago and my car sat outside through winter for half a hear until I got my license back. It was getting moisture inside and thats probably how the CAS module went bad since it’s very sensitive.

mhm interesting. what if you try removing the CAS module and letting it "dry out" it could be failing but it still has some life in it.