Kann nich Motor starten (E46, 2002)

Zitat

Original von Nutzername23
No problem for this help, thats why this page exists.

Back to your problem:
You see what I mean, they change (expensive) parts for nothing, only for the reason they THINK it could be the suspicious device.

Your problem is really strange because your car suddenly stopps. From this distance its hard to make a reliable diagnosis. Do you have a protocol of the fault recorder? I hope you know what I mena, I am not sure if this is the right translation for "Fehlerspeicher". What I mean is that you can connect your car with a computer. Then you can see all the faults which occured during the last time. Maybe you can find an indication...

Can you repair your car on your own? I guess not... ;))

With the marten, I think it is just a possibility you should think about. Just take a look in the engine compartment and watch out for any traces of this cute but annoying animal.
Your error which occurs as a random failure might be a short circuit...you should have a look at the fault recorder which I told you about at the beginning. Then you should post it here or send me to my email...

Dont worry about your German, its good enough.

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I guess I can not repair car on my own. I was able to do small things like : replacing environmental sensor, installing an interface for iPod and etc myself, but this case i believe is more difficult. Plus requires some equipment, like to pull the car up

I know what you mean about this error messages. My car is in the garage right now (they put it outside and dont do anything, since I expect some help from BMW CustomerCare Munich. While talking to this department they said that BMW Engineers could help masters of garage remotely in case of need, but it takes several days normally before my complain is being processed and they could react). I don't have access to this error log read from the car. According to the master, there was no errors or they were misleading. At the moment I don't have them

I have spoken regarding weasels (marten) with the master. Somehow he is confident that it is not the case. The arguments he used were: they don't bite fuel pipes (initially he was thinking that it was a failure of fuel system). My model does not have wires directly accessible to the animals, they are hidden in looms (protections around several wires going the same way). According to him they investigated weasels damage, but none was found

Thank you for your help! As I said my current plan is to wait few days for BMW Munich to help resolve this matter. If it does not happen or brings no results, I will move my car to better garage (which was mentioned here already)

sorry for a delay with the answer - I was away yesterday

Slava

Hello FriendlyKiwi!

thanks a lot for your messages and hints!

Zitat

Original von swiki
(we have been talking on another forum, it is FriendlyKiwi here

OK, done some research about your problem

Based on your N42 motor controlled by the ME9 engine management system (DME).

[quote from BMW manuals]
Battery voltage monitoring

The battery voltage is continuously monitored in the DME. At a battery voltage of less than 2.5 V or greater than 24 V, a fault is entered. The diagnosis only becomes active 3 minutes after engine start-up. This means that the effects of the starting process or starting assistance on the battery voltage are not regarded as a fault.

Fuel Pump
The fuel pump is located in the fuel tank. It is switched on and off by means of a relay and delivers the fuel via the fuel filter to the fuel distributor pipe.

Fuel pump relay
The control unit can only monitor activation of the relay but not of the pump itself. A safety circuit ensures the relay can only be activated with the engine running and only shortly after switching the ignition lock to position 2 in order to build up pressure.

Once the engine shuts down, the DME control unit no longer recognized engine speed and immediately switches off the relay. This ensures that the fuel pump cannot continue running when the engine turned off.
[end quote]

[here is my analysis]

The DME (digital motor electronics) controls the fuel pump in the E46 via a relay, K96

The fuel pump is protected by fuse F54, 15A

Before you start hunting for weasel damage, I recommend:

1. Replace fuse F54 (15A) with a new (or spare) one. Sometimes fuses develop hairline cracks that cause problems with vibration and heat. The fuse is very cheap to replace, try a new one.
F54 is located in the fuseholder above the glovebox.

2. For the same reason, replace fuse F3 (20A). This supplies power to the fuel pump relay, the secondary air pump relay and the AC compressor relay. If this fuse is cracked, you will loose power to the fuel pump relay. F3 is in the fuse carrier in the engine bay electronics box.

3. Replace the fuel pump relay K96. Tarnished or burnt relay contacts cause many electrical problems. If the fuel pump looses power then fuel pressure will be lost and the engine will stop. A new, quality BMW relay is cheap and easy to fit. Relay K96 is located behind the glovebox, the leftmost of 4 relays.

4. Check loom connector X6021 for corrosion and water damage or loose fitting. it is located in the electronics box in the engine bay where the DME is. Power to the fuel pump (and secondary air pump relay and AC compressor relay) go through pin 2 of X6021 (red wire with white stripe). If this has a bad connection, power to the fuel pump relay might become intermittent.

5. I think it is impossible to have weasel damage in the fuel pump wiring, as the relay and fuse are in the glovebox, and the wiring from the relay to the pump goes through the inside of the car.
However, the DME is in the engine bay and the DME controls the fuel pump relay. Some wiring from the DME to the inside of the car may be exposed. This is where one should inspect very very carefully.

7. A way to diagnose the fuel pump: the fuel pump has 2 x wires on the fuel pump connector. Blue/white (12V power) and brown (ground)
Run 2 x temporary wires from the fuel pump connector to a small 12V 5W light bulb that can be placed in view of the driver. The light bulb will light when the fuel pump is running. Drive the car, and monitor the light bulb. If the light goes off and then the engine fails, it proves lack of power to the fuel pump.

Well, that probably exhausts all possible fuel pump power issues - if you work through the above and change fuses and relay and check the loom connector and monitor the pump, you will know for sure the state of your fuel pump.

Swiki aka FriendlyKiwi

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I am feeling sorry, since I did not say it very clearly that fuel system was checked already in the garage. They had replaced fuel pump by a new one, but the problem was still there. I don't know about fuses and relays though, I will ask master next time when I visit the garage.

I will dare to ask you another thing : Is there a way according to your manuals to check whether engine control unit is working properly? they said "there was not signal coming from it to the fuel pump, so it was broken." (I guess they meant to fuel relay instead of the fuel pump directly according to your manual above). This box costed me alone (as replacement part 1200SFR). They installed new one and the problem still exists. They say "old one is broken anyway". Personally, I dont believe there is a big chance to have 2 things broke at the same time in the car. If old box is working, that means that whole bill (about 2000SFR) should not be charged to me at all.
Since they insist on failure of old one, I might do the following: take a new one installed and ask for the old one (since it belongs to me). And I would like to check the old one afterwards

Thanks a lot mate for info!!

p.s are these manuals available to buy somethere?

SlavaR

Zitat

Original von Nutzername23
The case with the marten is improbable I know, but a case that MIGHT happen.
BMW knows this problem, thats why alle the cables have an extra protective cover as u mentioned before. But I have seen cases where this hairy animal destroyed the wiring although there was this protective cover mounted, maybe this animal was very very hungry. Useless to say that you can see this of course...

Anyway the fuel lines or electric connections to the fuel pump are impossible to reach for this animal because they go through the inside of your car, but it is possible that the fuel pump itself is working but the pump doesnt get a signal for some reason.

Unless the error report doesnt give any useful hints and your car is still in the garage, we only can guess what could cause this problem.

Think about what Swiki wrote, this guideline seems to be very useful if the fuel delivery system is responsible for your problem.

Let us know please....

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Sure, please get me right. Personally I would be happy if the root cause will be marten (since I have it covered by my insurance). I said to the master that I heard that they could bite the cables and it is difficult to find. He answered that he knows about it and they had checked it, but no damage was found. He was so confident that I started to feel that I won't be able to use the insurance to cover it

I know that without the physical access to the car and error log, it is difficult to say. Only blindly guesses and it could be many reasons for car failing. I appreciate the help you gave me here, I am not intending you guys to list me every possible reason. Once it is resolved by current garage or the new recommended one, I will let the know the root cause of course.

thanks a lot again!!

Hello Kiwi,

thank you the links and info!

hmm.. the control unit was sold to me for the full price (I called BMW part dealer in Zurich and asked them for the price. They said nearly the same, i.e. 10$ difference). I am going to chat about it with the garage then

I will check the links at home, since website does not want to work from Mac

have a good evening!
SlavaR

Wanted to make an update on this story. I brought my car to Bickel BMW garage (as it was suggested by some people here): he is a nice person and he did a thorough checks. Main relay switch was replaced and since then I did not see any problems (it was already 3 weeks, so I had time to make sure it is really working).

thanks a lot everyone for the help! and the good advise to use bickelauto garage. It is great indeed!

so to sum up: control unit was replaced, but the problem repeated. After replacing main relay switch it had gone.