Help: Car does not start (till after a break)

[bmw_e46]

Hi fellow m3 drivers,

car (E92) has been acting up. So frustrating !

1) started with the sign of clock being reset
2) one day could not start
3) Tried to jump start, no use
4) Towed car and got battery replaced but still could not start
5) the check engine light is not coming up.
6) Car left at workshop, diagnostics showed it might be CAS.
7) strangely, 24hrs later, car started. No idea what was wrong. various modules were updated.
8) next day, same thing happened. Car started ok the 1st time, then after stopping, car could not start. Decided to leave it there, and low and behold, 4 hours later, the thing started.
9) Brought it to the shop, when it runs, diagnostics shows all ok. Grrr.... but then while later, stopped the car, left the door open. could not start again. All other electronics work but car does have the check engine at all. Again, diagnostics seem to suggest CAS.
10) Seemed that teh CD changer (Idrive) was not shutting down properly. You can hear it spinning. Tried the reset many times, but does not stop. Anyway, in the end, Ordered and changed the CAS module. Thought all would be fine right....
11) Err.r....car could not start. same symptom. it can start 1st time, but needs to have a 'break' , before it can start up again. in between, what u do, does not seem to help. However, with CAS change, the diagnostic changed targets. Now it is saying wake up line and IBS. However, IBS when changed, still no effect.
12) At wits end.... even workshop is stumped.

Anybody has a similar experience and can share. Much appreciated.

Mean time, car is a sitting lemon.

Thanks in advance for reading.

[bmw_e46]

Any body who can help ? or give hints ?

New Batt, IBS & CAS... done.

thanks

[tibra1]

Take it to BMW?

[bmw_e46]

Hi Jake,

Thanks for this. Tried with both keys and mine is non-CA.

Also, checked the grounds at the +ve at the engine bay, as well as ground in the trunk. both secure.

But you are right about the corrosion hint... i have checked the TSB 61 08 11 so looks like will need to check the wire behind the fuse (which have not been done yet). But this TSB states that the whole car is 'dead'.

however, the funny thing is that in my case all other electronics work.

Have searched many many threads but not many have the same symptom as mine

another interesting pc of info: ran check with Autologic and it is saying IBS & wake up line fault. a wake up line fault comes when termninal 15 is not matched with IBS & BSD... any body knows how to explain how this can happen ?

thanks again.

Originally Posted by JakeB

Have you used the same key every time the car won't start? I would start there first if you havent tried another key as a key that is bad or on the fritz will not usually set a fault at all. If you have already tried that I would be looking at the chassis and engine grounds as they will prevent engine cranking if they are loose or corroded. Let me know.
Jake

[bmw_e46]

Thank Jake for the hints.

yes, IBS & CAS were replaced.

shall check them and revert...am praying hard, its one of these... its a sweet car... love it to bits.

Originally Posted by JakeB

You said the IBS and CAS were replaced already? I have seen where the car wont start and other electronics work. I would want to remove the JB and look at the cable and JB for discoloration or melting. This is very common. If that proved to be ok than I would check the engine ground as well as the power distribution block on top of the battery. These are all places I would look. There is also a possibility that there is a line or wire fault due to the ibs bsd faults, these are in the back by the battery and run all the way to the alternator. If I had the car I would figure it out but I hope this helps!
Jake

[bmw_e46]

Checked the cable from the batt to fuse. all Good.

checked grounds in boot and front of enginer. all good.

Running out of options

latest fault codes:

1) 2791 IBS general
2) A732 wake up line

Someone with more hints ?

thanks

Originally Posted by bmw_e46

Thank Jake for the hints.

yes, IBS & CAS were replaced.

shall check them and revert...am praying hard, its one of these... its a sweet car... love it to bits.

[BPMSport]

I would reprogram CAS and NFRM and junction box to latest versions + recode.

Maybe the IBS cable you have is bad? I had some of these issues where the car wouldn't start three years ago. They replaced the IBS cable and I haven't had a single issue since.

It has to be a ground or some sort of connection that is severed if it's not the modules causing the fault.

[bmw_e46]

Hi Mike, thanks for the reply.

the car has been completedly recoded with the latest versions.

question is how do i know if its a BAD IBS ? its a non-repaireable part.

at the moment, its down to checking grounding inside the car compartments... just started with the one at the driver's side footwell, looks good

the car got stuck again whilst waiting at the car wash. After waiting about 3hours, it started again.

Pretty easy to judge, if i see the DCT gear light up when unlocking the car, i know its good to go.

however, 1 disturbing thing is whilst checking the car when it was down, there is still about 5v running on the wakeup line. logic is that it should be 0 or 12v, hmmm..... once everything works. the voltage flow is as expected.

anybody can explain this part ? wake line having some voltage of 5+ running.

thanks all

Originally Posted by Mike Benvo

I would reprogram CAS and NFRM and junction box to latest versions + recode.

Maybe the IBS cable you have is bad? I had some of these issues where the car wouldn't start three years ago. They replaced the IBS cable and I haven't had a single issue since.

It has to be a ground or some sort of connection that is severed if it's not the modules causing the fault.

[BPMSport]

No Problem..

I doubt it would be grounding inside the car.. Have you checked where the negative cable connects to the chassis in the rear?

I would connect a laptop to the OBD port and try to see if KL15/Terminal 30 is activated when you are having this problem. It's important to see if everything is getting power at the time of the fault occurring..

You should be able to "wakeup" the cas and frm by pressing buttons, like start button, try navigation volume button etc..

I would think that if it's not an IBS or grounding problem, that the CAS or NFRM has a problem..

It's difficult to diagnose a faulty IBS cable other than checking the connections to make sure they are tight.

And when you say wake line, what wire specifically are you referring to?

Originally Posted by bmw_e46

Hi Mike, thanks for the reply.

the car has been completedly recoded with the latest versions.

question is how do i know if its a BAD IBS ? its a non-repaireable part.

at the moment, its down to checking grounding inside the car compartments... just started with the one at the driver's side footwell, looks good

the car got stuck again whilst waiting at the car wash. After waiting about 3hours, it started again.

Pretty easy to judge, if i see the DCT gear light up when unlocking the car, i know its good to go.

however, 1 disturbing thing is whilst checking the car when it was down, there is still about 5v running on the wakeup line. logic is that it should be 0 or 12v, hmmm..... once everything works. the voltage flow is as expected.

anybody can explain this part ? wake line having some voltage of 5+ running.

thanks all

[bmw_e46]

Hi Mike,

yes, check the cable at the rear. There is another in the engine compartment. Both are tight.

I have researched about the wakeup line fault:

>>>
Terminal 15 Wake-up Signal Faults
The IBS recognizes wake-up line faults. The IBS can detect a wake-up line error under
the following conditions:
• DME “ON”
• Terminal 15 “ON” (voltage high at IBS)
• Terminal 15 running via BSD
If Terminal 15 at the IBS and Terminal 15 via the BSD are not equal, a fault is indicated in the BSD line or an IBS Fault.
<<<

With regards to software, with autologic, the car has the most updated versions.

Yea, you see the interesting or rather distrubing thing is that when experienceing the problem of non-start, there is currrent running in the PT-CAN Wakeup line (when we plug in the autologic). The question is what is causing this... hmmm ???

As the problem is intermittnent, meaning, if you let the car 'rest', it starts up after a while. So, that is really throwing things up in the air...

If its wiring or software, we should assume that the car either starts or does not..... one of the cause (guessing....):
1) something in the car is still sucking power when it is left sitting there
- question... above what amps should we worry ? 20 ?

2) when the car is driven and 'heated' up, a connection/contact expands becomes less 'contactable'.... once it cools, its back to normal.
- hence checking grounding to try to eradicate this possibility.

*gosh*... this gremlin is seriously driving me up the wall

but, when you love an M3 , you have to stick to this love affair and not stray when the going gets tough

ok, more ideas/hints to sort this is appreciated... to the one who finally gets it

Originally Posted by Mike Benvo

No Problem..

I doubt it would be grounding inside the car.. Have you checked where the negative cable connects to the chassis in the rear?

I would connect a laptop to the OBD port and try to see if KL15/Terminal 30 is activated when you are having this problem. It's important to see if everything is getting power at the time of the fault occurring..

You should be able to "wakeup" the cas and frm by pressing buttons, like start button, try navigation volume button etc..

I would think that if it's not an IBS or grounding problem, that the CAS or NFRM has a problem..

It's difficult to diagnose a faulty IBS cable other than checking the connections to make sure they are tight.

And when you say wake line, what wire specifically are you referring to?

[BPMSport]

Originally Posted by bmw_e46

Hi Mike,

yes, check the cable at the rear. There is another in the engine compartment. Both are tight.

I have researched about the wakeup line fault:

>>>
Terminal 15 Wake-up Signal Faults
The IBS recognizes wake-up line faults. The IBS can detect a wake-up line error under
the following conditions:
• DME “ON”
• Terminal 15 “ON” (voltage high at IBS)
• Terminal 15 running via BSD
If Terminal 15 at the IBS and Terminal 15 via the BSD are not equal, a fault is indicated in the BSD line or an IBS Fault.
<<<

With regards to software, with autologic, the car has the most updated versions.

Yea, you see the interesting or rather distrubing thing is that when experienceing the problem of non-start, there is currrent running in the PT-CAN Wakeup line (when we plug in the autologic). The question is what is causing this... hmmm ???

As the problem is intermittnent, meaning, if you let the car 'rest', it starts up after a while. So, that is really throwing things up in the air...

If its wiring or software, we should assume that the car either starts or does not..... one of the cause (guessing....):
1) something in the car is still sucking power when it is left sitting there
- question... above what amps should we worry ? 20 ?

2) when the car is driven and 'heated' up, a connection/contact expands becomes less 'contactable'.... once it cools, its back to normal.
- hence checking grounding to try to eradicate this possibility.

*gosh*... this gremlin is seriously driving me up the wall

but, when you love an M3 , you have to stick to this love affair and not stray when the going gets tough

ok, more ideas/hints to sort this is appreciated... to the one who finally gets it

You need to perform an energy diagnosis with the factory software. It takes hours but will give you a full report on exactly what is staying awake and causing the issue. I am not sure if the Autologic does it though.. ISTA/P running on an ISSS machine should be able to do it..

[bmw_e46]

Hi Mike,

have checked through and found the after market alarm drawing power.>40amp. now that it is disconnected, the power when the car is at rest is a nice 11amp. so looks like we have sorted out the power.

however, took it for a long drive about 45min and the same thing came back.

this time, had the autologic on hand, it shows that there is a 4.5v on the wake up line. This is strange. anyway, left the car to 'rest'. about 4 hours later, went back, checked that the everything was back to normal and car could start.

any ideas, why there would be power running through the wake up line at that voltage ? i am expecting it to be 0 or about 12V.

thanks

Originally Posted by Mike Benvo

You need to perform an energy diagnosis with the factory software. It takes hours but will give you a full report on exactly what is staying awake and causing the issue. I am not sure if the Autologic does it though.. ISTA/P running on an ISSS machine should be able to do it..

[BPMSport]

I would remove any other potential aftermarket equipment on the car, reflash the entire car, and perform a battery reset.

[bmw_e46]

thx. shall try this.

am trying to avoid a DME replacement

any idea, how the wake up line is powerred ? each time it cant start, the line shows voltage abt 4-5v on this line.

Originally Posted by Mike Benvo

I would remove any other potential aftermarket equipment on the car, reflash the entire car, and perform a battery reset.

It's possible that the drain from the alarm was causing unfavorable choices to be made by the IBS system.

[THE TECH]

Make sure that the wires used to tap for the aftermarket alarm are in good working order. Maybe some sort of short is causing the issue?

[M3Denver]

When the car doesnt start does the engine turn over at all trying to start or is it just dead?

[gblansten]

If you and the car are on a break do you think it is ok to see other cars?

[BPMSport]

I highly doubt that replacing the DME would rectify the issue.

[tom @ eas]

Originally Posted by THE TECH

Make sure that the wires used to tap for the aftermarket alarm are in good working order. Maybe some sort of short is causing the issue?

+1

Someone could've possibly accidentally tapped into a CAN wire when installing the aftermarket alarm. This can cause all sorts of wacky behavior just as OP is describing, including not letting the M3 properly enter into sleep mode.

[BPMSport]

Originally Posted by tom @ eas

+1

Someone could've possibly accidentally tapped into a CAN wire when installing the aftermarket alarm. This can cause all sorts of wacky behavior just as OP is describing, including not letting the M3 properly enter into sleep mode.

True, anything going on with the CAN wires will cause really strange issues.

There are two CAN wires, CAN Hi and CAN Low. CAN is a twisted pair wire network, with a 5V reference signal. If you scope it, you should see lots of peaks and valleys that sort of mimic eachother when comparing CAN Hi to Can Low. (Can Hi from 0 to 5V and can Low from 0 to -5V)

If there is a module that is defective or malfunctioning on the CAN network, this can also cause weird issues as you are describing.

I would remove all aftermarket equipment and go from there.

I have been working on a theft recovery 2006 E60 M5 in Mississippi. Complete car was pretty much dead, no power seats, hud, iDrive, buttons on center console dont work, etc.. Turned out to be that the MOST bus connection was backwards at the TCU, and the fusebox had five extra fuses in it and this was completely knocking out the CAN network.

Now all is good

[bmw_e46]

Originally Posted by THE TECH

Make sure that the wires used to tap for the aftermarket alarm are in good working order. Maybe some sort of short is causing the issue?

have removed the after market tracker / alarm. it was hooked direct to the 30g and drawing power. but kindda a strange it took such a long time to finally bring the car power down, assumed it might be defective.

do you have experience, what kind of shorts typiclaly happen. have checked the grounding points too.

thx

[bmw_e46]

Originally Posted by M3Denver

When the car doesnt start does the engine turn over at all trying to start or is it just dead?

the car is just sits there pretty... everything works but the starting...

but once the car 'rests' enough and starts... roars to life