E93 M3 Random starting problem. (100% SOLVED)

[SaNGRia]

Finally I have had the chance to record this random starting problem to try to pin point the cause of the problem and I was researching lots of forums over the last 6 months to find out what could cause this problem in my 2008 e93 m3 vehicle that I drive only on Sunday.

I will write some information about my symptom first. My car never experienced this problem on a cold start before today. The problem was occurring after I would drive and stop at three or more places when the car was warm, so I focused on a warm start problem before today and the reason I couldn't record since then was I was always outside my house and usually by myself when the car was having this issue, but today I wanted to wash the car and when I tried to start in my garage it happened again. I called my wife and kids and one of them was trying to start the car while the other one recorded. I measured the voltage from my 5 month old OEM battery that I originally replaced since the problem was happening.

After 6 month research, I have learned a lot about the BMW Engineering and not to waste my money to find out what is wrong with my car, but instead I tried buying a part and trying to fix the problem. Other people on the forums had bought a starter and it did the same thing, or changed the battery and it did again or change the alternator, but then they found out it was only a battery cable problem etc.

So I got Native ISTA/P and ISTA/D with KDCAN and started reading all the starter diagrams to find out what could possibly be causing the problem. After too many readings what I learned is to check all the battery cables and measure the battery voltages. EWS system was on the list, but it’s 99% not my problem because when you have EWS based problem it usually starts and stops immediately. So my symptom is that everything turns on, voltage is always 12.4-12.6 (since I am charging with an original BMW Battery Maintenance Kit) and the car just randomly either starts or rejects starting and makes a clicking noise that you will see on the video below.

So if there is a clicking noise there are several solutions for that. One of them is to check all the cables (including ground and earth cables) to make sure they are tight and not corrupted.
Secondly check that the solenoid is not working properly (since I was always having problem while the car was hot, I researched hot starting problems and found out soloneid could have some problem when it gets hot and heat soaking making this issue, but since I got the same problem today when the car had been sitting for 5 days in the garage, that heat soak issue is not in the list anymore)
Thirdly, the ignition switch or relay can get damaged and not give the right current to feed the starter and just makes the clicking noise or Clutch sensor that allows us to start the car can get damaged and not work proper anymore or IBS cable on the battery is damaged.
Last on my list is that the starter has a problem and needs to be replaced. Before I spend any money on them,I need your help to pinpoint the issue in this case and not to be forced to sell my brand new looking M3 out of frustration.

I am just upset that I had experienced this issue with a very well maintained 35k miles car and I bought from the first owner thru BMW Dealer and the car was in spectacular condition. The car doesn't give any error codes at all. Neither the INPA or ISTA D program gives any error or stored error code whatsoever. Only the problem on the car was when I first purchased it, it threw SES Light and it was Fuel Rail Pressure sensor issue which was taken care of by BMW dealer and they replaced (09 or newer generation m3) sensor with the ECU update. Since I only drive the car on Sundays, it is very hard to duplicate the problem, and that’s why it took too long to analyze for me. Since I read lots of forums and experiences, I didn't want to go to dealer because many of them said they couldn't replicate the problem or the dealer suggested to replace the CAS or Starter Or Alternator and thousands of dollars would be spent and the problem would still exist! So I need really experienced BMW pros to give me a hand on this one. Here are the videos:

1st one when i am having starting problem on cold start

The first video car started and run like 2 minutes and then stopped the car and washed it and the video recorded right after the car wash done

After that video i noticed that my rear left tire pressure warning on the idrive and told my wife to drive to the Gas Station right next to our community (about a mile away) and we parked the car at the air pump place. I put air in all of the tires and went to start the car and it didn’t start! The car did not start until after three attempts. So i am starting to think since it’s happening more often today with a cold start, it is %80 percent a starter problem! But I really want to make sure what the problem is.

My questions are: In order to measure the voltage on the starter and solenoid, I have to remove the air intake right?

Let say I removed the air intake, will I remove the Positive and negative cables from the solenoid in order to measure the voltage? The weird part is how can I know that voltage is not changing? Because the car usually starts after three or four attempts, and worse being ten attempts.. I mean I really need to wire an extra cable from solenoid and stick them outside of the intake cover and whenever I have the issue I should start measuring the voltage other then that car already starts after 3 times attempt !! Like how can I do that? I called the dealer and explained everything and they said bring to us and let’s try to replicate the problem and we will try to measure the voltage on the starter. If we get the right voltage reading then we will check the solenoid and starter. If we don’t get the right voltage reading to the starter, then we will check the relays, cables and modules. My question is: When you replicate the problem you do not have too much time to wait and diagnose. What are they going to do… remove the intake and measure the starter and solenoid voltages? It does not make sense to me because during that time the car might start every time they try to start it. So they cannot start the car while the intake is removed or it may receive the right current after the intake is removed. I am obsessed with this problem and I really need some attention here! Thank you.

Last I measured parasitic battery drain using my multi meter and ammeter wasn’t between 25-50 it was way less then this so I don’t think I have a drain either!

Engine start

The overall sequence for starting the engine can be described as follows:
The remote control is inserted in the ignition lock.
· A ring coil in the CAS control unit feeds current to the data memory in the remote control and the EWS data is read. If the remote control is a valid and enabled key that belongs to the vehicle, it is locked in position in the ignition lock.
· After this locking, the CAS sends the command (terminal R on) across the data buses. This activates a number of control units.

Pressing the start-stop button
When the start-stop button is pressed, terminal 15 is activated first of all.
· Activating of the four outputs, terminal 15 in the CAS. The relief relay for the ignition coils is switched on via terminal 15-3.
· Activation of the three outputs terminal 15 WUP (wake-up) in the CAS.
On activation of the outputs terminal 15 WUP (wake-up), all the control units connected to the PT-CAN data bus are activated.

When the start-stop button is pressed, the CAS checks whether the brake pedal is pressed and the gear selector lever is at P or N. If this condition is met, the engine is started:
· Across the line terminal 50E, the CAS switches a positive (battery voltage) at the DME control unit, signaling that the engine is to be started.
· Across terminal 50L, the CAS switches a positive (battery voltage) at the comfort start relay. The starter motor is switched on.
· Via the data line D-EWS; a random code of EWS is transferred to the DME control unit.
· The engine control unit compares the transmitted random code with the calculated code. If they match, the ignition and the fuel injection are enabled.
· The starter motor turns until the CAS control unit receives the signal (Engine running) from the engine control unit via the data bus. Then, the terminals 50 in the CAS are switched off.
If the engine does not start, terminals 50 are deactivated after a maximum of 20 seconds and the engine start is aborted

Here is the Convenient Start Wiring Diagram and all the possiblilties according to starting system of e9x m3

[TTO898]

tl;dr; gl.

[anom3]

Yikes, tough luck

Yeah to check the starter you need to remove the pleneum or whatever its called. The big black box on top of the motor. You will also need to remove / move quite a few other items out of the way. The starter is located near the back of the motor, in between the 2 heads. Kind of a pain to get to.

Here is a good image of where the starter is located... In this image its removed, but this should give you a good idea.



As far as EWS... Not 100% sure, but I think it would throw a code.

But yeah, starter is where I would start checking next for sure. Also, its ok to start the car with the big black box off. But your idea about wiring wires and running them out so you can test whenever need be is good too. Yeah I know, very time consuming...

Another simple thing to try would be if you have a 2nd key, try using that key and see if it helps.

[anom3]

Another thing I would try before attacking the starter:

Before starting it. Disconnect, wait a couple of minutes and reconnect your battery. See if having the ECU's do a sort of reboot helps. If it does, you know its not the starter.

[SheaButter]

Originally Posted by anom3

Another thing I would try before attacking the starter:

Before starting it. Disconnect, wait a couple of minutes and reconnect your battery. See if having the ECU's do a sort of reboot helps. If it does, you know its not the starter.

+1 to the hail mary. It COULD be a starter, but I have a feeling it's another little gremlin causing the problem.

[SaNGRia]

Hello. Thank you for the advice. Let me post some DIY picture for Air Intake and Starter Removal for E9x M3 that can be helpful those who have problem with that in the future.

Here is How to remove Intake Cover :








This is the tool




And How to remove starter :
At the first picture you can see that you can replace the solenoid by itself, But BMW DEALER told me that no you can not, i guess they know better than Bmw original part producer and engineers



This is the Power supplies

This is the DME Master Relay under the hood

Originally Posted by anom3

Yikes, tough luck

Yeah to check the starter you need to remove the pleneum or whatever its called. The big black box on top of the motor. You will also need to remove / move quite a few other items out of the way. The starter is located near the back of the motor, in between the 2 heads. Kind of a pain to get to.

Here is a good image of where the starter is located... In this image its removed, but this should give you a good idea.



As far as EWS... Not 100% sure, but I think it would throw a code.

But yeah, starter is where I would start checking next for sure. Also, its ok to start the car with the big black box off. But your idea about wiring wires and running them out so you can test whenever need be is good too. Yeah I know, very time consuming...

Another simple thing to try would be if you have a 2nd key, try using that key and see if it helps.

[BPMSport]

Without a doubt, this is not related to EWS.

Even with an EWS mismatch, the engine will turn over. It will not start, but it will crank a day.

I would replace the IBS ground cable in the trunk. This is likely the cause of the problem, if there aren't any loose connections.

[SaNGRia]

Thank you for the advice. The problem is Let say i tried to start the car and it did not start, we do not know that the car will start at the second attempt or not. So Let say i tried and didn't start and than i remove the battery cables and reset the ECU, maybe car would start before reseting the ECU at the second attempt and when i plug back the battery cable car started and i will think, yeah starter working maybe modules has problem, but we do not know when the car wants to start or not so it is not going to help me to pinpoint this issue. And the reason i am researching and sharing here is not to attack to starter or any other possible parts that can caused this problem. I want to hit the right part and fix the problem. If my car was E60, E63 or E64 there was a very high possibility that i need to replace my "integrated supply box module". It was most likely the issue for this modules other than replacing starter or alternator or battery. But we do not have this. As my knowledge our cars ignition system managed by CAS electrical module and it usually throws codes when there is something wrong on it

Originally Posted by SheaButter

+1 to the hail mary. It COULD be a starter, but I have a feeling it's another little gremlin causing the problem.

[SaNGRia]

Originally Posted by SheaButter

+1 to the hail mary. It COULD be a starter, but I have a feeling it's another little gremlin causing the problem.

if it is the starter, it is worse than Pepboys after market Lifetime warranty starter then!!! 35k miles and its dead? Label is Valeo! So if it comes out starter issue i will def contact with the factory of valeo and complain then!

[SaNGRia]

So Should i wire the cables to starter and stick them out side of the intake and secure them with the plastic wire protection covers and whenever happens again i can check the current on the starter whenever push the start button. And i read somewhere that, the voltage should be 12V or more and BMW did a weird thing that whenever you push the start button it drops to 0 Volt and when engine starts goes back to 12V is that right? And if i wire extra cable, which cables i am going to extend? Big Red + cable which comes from Battery and Little black cable which comes from solenied ?

[SaNGRia]

Originally Posted by Mike Benvo

Without a doubt, this is not related to EWS.

Even with an EWS mismatch, the engine will turn over. It will not start, but it will crank a day.

I would replace the IBS ground cable in the trunk. This is likely the cause of the problem, if there aren't any loose connections.

Do you know how to check this cable is functional or not? IBS is on the list but i don't know how it effects the system when they re going bad!

[SaNGRia]

Originally Posted by SaNGRia

Do you know how to check this cable is functional or not? IBS is on the list but i don't know how it effects the system when they re going bad!

Update : If IBS sensor has problem it is stored on DME Error data. So I don't have any stored data like this!

[BPMSport]

Originally Posted by SaNGRia

Update : If IBS sensor has problem it is stored on DME Error data. So I don't have any stored data like this!

Not necessarily.

[SaNGRia]

Originally Posted by Mike Benvo

Not necessarily.

so do you know how to test it tho? I think I should test the electrical voltage on the starter first before doing anythingelse . If I am getting right voltage while trying to start the car so it is definetly something wrong either on solenoid or starter. If the voltage is less than 12V then I should look for different avenue?

[BPMSport]

I would replace the IBS cable. I would defer to MileHighM3 on how to test its functionality. He's a very bright foreman at the dealership. Try shooting him a PM.

[Sered]

Pull your battery and the tray it sits on. You've probably got water leaking into the bottom and not draining so the connection gets gummed up. Semi common occurrence.

Also, practice brevity. I had to read half of your post (which gave me a headache due to no paragraph structure) to actually figure out what the symptoms were.

[SaNGRia]

Originally Posted by Sered

Pull your battery and the tray it sits on. You've probably got water leaking into the bottom and not draining so the connection gets gummed up. Semi common occurrence.

Also, practice brevity. I had to read half of your post (which gave me a headache due to no paragraph structure) to actually figure out what the symptoms were.

The battery that i have right now is replaced by me and registered with Tool32 . I purchased an OEM Battery from S/Dealer and i did the replacement. This car never even driven in the rain. Always garage kept and i never seen water in the tray either. And this problem was in the car before the battery replacement. But if it was a water leaking it makes sense what you are saying. And sorry for the long writing

[SaNGRia]

Originally Posted by Mike Benvo

I would replace the IBS cable. I would defer to MileHighM3 on how to test its functionality. He's a very bright foreman at the dealership. Try shooting him a PM.

Thank you so much. I will pm right now! (I just noticed ironically enough he replied my older post few hours ago )

[Sered]

Originally Posted by SaNGRia

The battery that i have right now is replaced by me and registered with Tool32 . I purchased an OEM Battery from S/Dealer and i did the replacement. This car never even driven in the rain. Always garage kept and i never seen water in the tray either. And this problem was in the car before the battery replacement. But if it was a water leaking it makes sense what you are saying. And sorry for the long writing

I think you misunderstand. Pull the tray the battery sits on. The wire for the starter/alternator runs under the tray and connects to a separate terminal. That terminal can easily become submerged even with just a small amount of water. If it happens enough times, it will degrade and cause the exact issues you're describing.

Mine was so bad I had to chop off the end and redo it with a battery extension cable and terminal. I've heard its semi-common as the water gets in behind the gas cap to body seals and drains down there.

[SaNGRia]

Mmm, yeah it gives me a wish. So here is a picture of e9x m3 tray. Can you show me ?


I mean i checked my positive Red big battery cable under the car. And yeah i read some of the people experience that cable corroded. So you want me to look at the bottom of the tray where this cables are connected? And remove them to check it?

Note: When i asked the technican at the Dealer, He said if you have a connection problem on your cables it will show a sign like your clock reseting or your Idrive showing some signs. Did yours do something like that while you were experiencing correded cable issue?

Originally Posted by Sered

I think you misunderstand. Pull the tray the battery sits on. The wire for the starter/alternator runs under the tray and connects to a separate terminal. That terminal can easily become submerged even with just a small amount of water. If it happens enough times, it will degrade and cause the exact issues you're describing.

Mine was so bad I had to chop off the end and redo it with a battery extension cable and terminal. I've heard its semi-common as the water gets in behind the gas cap to body seals and drains down there.

[X5-User]

SaNGRia How can I download this software for DIY?

[Sered]

Originally Posted by SaNGRia

Mmm, yeah it gives me a wish. So here is a picture of e9x m3 tray. Can you show me ?
Attachment 1233321

I mean i checked my positive Red big battery cable under the car. And yeah i read some of the people experience that cable corroded. So you want me to look at the bottom of the tray where this cables are connected? And remove them to check it?

Note: When i asked the technican at the Dealer, He said if you have a connection problem on your cables it will show a sign like your clock reseting or your Idrive showing some signs. Did yours do something like that while you were experiencing correded cable issue?

See the black terminal/box at the bottom that the red wire runs to? That's where mine corroded. The red wire running to it is routed different ways depending on the year, etc. Mine was/is routed from the left side of the tray going under it.

That is a clean tray, if that is yours, then you're not having any kind of leak issue. But no, you don't see any warning lights or anything if this particular cable has issues; the technician is wrong. This cable goes on a completely separate circuit to the starter. The only thing that happens when it is messed up is you can hear the starter click and it won't turn over. There's no engine warning light because this runs on a separate circuit.