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Discussion Starter #23
What is your model and engine type?
hahah its an E46 318i 1998 with the 4 cylinders M43B19 motor

btw they dont even have an engine check light or a E-OBD

i think it was one of the first models that Bmw published, and i think they are only in germany available.
 

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hahah its an E46 318i 1998 with the 4 cylinders M43B19 motor

btw they dont even have an engine check light or a E-OBD

i think it was one of the first models that Bmw published, and i think they are only in germany available.
😫 ok. But I think it's an electrical problem. Examine the DME and harness for signs of damage particularly where it comes into contact with the engine block or chassis. It seems that pin 8 on the central block of the DME is getting input from somewhere. Worse case scenario is replace DME. I hope I'm wrong. It would be nice if someone else on the forum could offer an opinon.
 

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I am going to ask the admin to move this to the General E$^ Forum rather than this General Regional Forum. Might get a bit more attention and input there.
 

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Discussion Starter #26
😫 ok. But I think it's an electrical problem. Examine the DME and harness for signs of damage particularly where it comes into contact with the engine block or chassis. It seems that pin 8 on the central block of the DME is getting input from somewhere. Worse case scenario is replace DME. I hope I'm wrong. It would be nice if someone else on the forum could offer an opinon.
this could be possible, the connector of the Crank sensor Has 3 pins 12v and 5v for signal, and the Ground, and some how when i connect the moltimeter to the 5v pin and the body of the car, the multimeter shows thar there is connection.
im not sure if this is normal, but i treid to do the same thing with cam sensor and there is no connection,

so maybe the cabel of the crank is broken somewhere and he is tuching the ground ?
 

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this could be possible, the connector of the Crank sensor Has 3 pins 12v and 5v for signal, and the Ground, and some how when i connect the moltimeter to the 5v pin and the body of the car, the multimeter shows thar there is connection.
im not sure if this is normal, but i treid to do the same thing with cam sensor and there is no connection,

so maybe the cabel of the crank is broken somewhere and he is tuching the ground ?
That's what I am thinking. The signal pin of the crankshaft sensor goes to pin 8 on that central connection block of the DME. All of the information on the internet says you have to have a signal on that pin for the car to start. That's not possible if the connector is unplugged. But you car is starting with the connector unplugged. That must mean that pin 8 is getting a signal from somewhere. Make sense?. Only possible source is a pin next to it or close by in the DME connection block. That's why I think it worth checking them out.
 

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Discussion Starter #28
That's what I am thiking. The signal pin of the cranshaft sensor goes to pin 8 on that central connection block of the DME. All of the information on the internet says you have to have a signal on that pin for teh car to start. That's not possible if the connector is unplugged. But youcar is starting with the connector unplugged. That must mean that pin 8 is getting a signal from somewhere. make sense?. Only possible source is a pin next to it or close by in th DME connection block. That's why I think it worth checking them out.
what do you mean with "DME Connection Block" and where do i finde it?
 

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ok Thanks man
Ok. I am struggling to find any information about your car's computer or its pin connections. But it doesn't appear to be anything like mine. So forget about the pins that I referred to earlier. However, I think the DME in this ebay ad is the one.

One of these pins shown in this picture will receive input from the crankshaft sensor. It may be receiving input from a pin close to it. So, find where this DME is located, remove the connectors and see if there is any sign of shorting or water access.

 

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Discussion Starter #32
Ok. I am struggling to find any information about your car's computer or its pin connections. But it doesn't appear to be anything like mine. So forget about the pins that I referred to earlier. However, I think the DME in this ebay ad is the one.

One of these pins shown in this picture will receive input from the crankshaft sensor. It may be receiving input from a pin close to it. So, find where this DME is located, remove the connectors and see if there is any sign of shorting or water access.

i will try today and see what will happend, i will tell you if i get it 😂

any way thanks for your time man.
 

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Discussion Starter #33
Ok. I am struggling to find any information about your car's computer or its pin connections. But it doesn't appear to be anything like mine. So forget about the pins that I referred to earlier. However, I think the DME in this ebay ad is the one.

One of these pins shown in this picture will receive input from the crankshaft sensor. It may be receiving input from a pin close to it. So, find where this DME is located, remove the connectors and see if there is any sign of shorting or water access.

do you think it could be a loose chain??
 

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do you think it could be a loose chain??
No. I don't think it's mechanical. I think it's electrical. Here is my logic.

If you look anywhere on the internet the story is that a car will not start without a crankshaft sensor.

This is no surprise because the computer doesn't know whaen to fire the plugs or open the injectors
because it doesn't know what position the crankshaft is in or where the pistons are. These events have
to happen at exactly the right point with respect to the crankshaft position in order for the engine
to fire up and keep running.

The crankshaft sensor communicates the crankshafts' position to the computer along the signal wire to
the computer. No signal, no communication.

But you clearly are able to start the engine even though the cable is unplugged.

So my conclusion is that, even though the crankshaft cable is unplugged from the sensor end the
computer end is still receiving a signal at the crankshaft position pin from somewhere else.

That somewhere else might be the intake camshaft sensor. The two cables are bundled together in
the wiring harness. If they are shorting out between each other that would explain why this is happening.
It is also possible that the short might be inside the connection block where the harness meets the
computer.

So that why I think you should be looking at the harness, for signs of waer or daage, and the connection
between the harness and the computer, for signs of water ingress, corosion or tracking.
 

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Discussion Starter #35
No. I don't think it's mechanical. I think it's electrical. Here is my logic.

If you look anywhere on the internet the story is that a car will not start without a crankshaft sensor.

This is no surprise because the computer doesn't know whaen to fire the plugs or open the injectors
because it doesn't know what position the crankshaft is in or where the pistons are. These events have
to happen at exactly the right point with respect to the crankshaft position in order for the engine
to fire up and keep running.

The crankshaft sensor communicates the crankshafts' position to the computer along the signal wire to
the computer. No signal, no communication.

But you clearly are able to start the engine even though the cable is unplugged.

So my conclusion is that, even though the crankshaft cable is unplugged from the sensor end the
computer end is still receiving a signal at the crankshaft position pin from somewhere else.

That somewhere else might be the intake camshaft sensor. The two cables are bundled together in
the wiring harness. If they are shorting out between each other that would explain why this is happening.
It is also possible that the short might be inside the connection block where the harness meets the
computer.

So that why I think you should be looking at the harness, for signs of waer or daage, and the connection
between the harness and the computer, for signs of water ingress, corosion or tracking.
i spoke to a bmw mechanic, and he told me those Engines Could run withou the Crankshaft Sensor,but they cant without the Camshaft Sensor.

but he said if you chain is loose maybe the signal from the two sensore is worng, and this could be the reason why my car is running better without the sensor.
but im not sure if i can believe him.
 

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i spoke to a bmw mechanic, and he told me those Engines Could run withou the Crankshaft Sensor,but they cant without the Camshaft Sensor.

but he said if you chain is loose maybe the signal from the two sensore is worng, and this could be the reason why my car is running better without the sensor.
but im not sure if i can believe him.
That's bullshit.

In the days before you had sensors and computers there was a thing called a distributor that was driven by a mechanical geared link to te camshaft. The distributor was responsible for firing the plugs in synch with the crankshaft. The camshaft was driven by the crankshaft through the timing chain or belt as they still are. The difference today is that the distributor is now replaced by the camshaft sensor and the DME computer. There is no way your computer can synch with the cranshaft without the crankshaft sensor.

The computer is just running a program. The program tells it do something when it receives an input from a certain pin. Example teh pin that is connected to the crankshaft sensor. When it receives a signal it fires a plug or opens an injector. If that input doesn't come the computer doesn't do anything. Those events don't happen. So how can your car run?

It's the same as you sitting at your keyboard now. You are on a website You press a key and the computer responds by printing a character on the screen. If you don't press a key nothing happens. The computer doesn't decide to type something for you.
 

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Hi, guys- responding to BigBopper's post on the general forum. Not European so I don't have a lot of exposure to the M43 engine, but I did do some digging.

There are a few posts where others have reported cars running in limp mode with the crank sensor unplugged. My guess is that the motor uses the cam sensor and makes a best guess to set ignition timing. Here's a post on bimmerfest where a guy is talking about his M54 running with the crank sensor disconnected: Disconnected Crank Position Sensor, now have issues

Don't mean to challenge you, BigBopper (and thank you for your help on the other thread!) but the DME may be inferring the crank position from the cam sensor when it doesn't get a signal from the crank sensor that it believes, and running in limp mode. I'm no expert but it seems possible, especially because these motors do appear to poll all three sensors and interpret the combined signal- there's reports of people throwing crank sensor codes when their camshaft sensor was really bad, and vice versa.

You may have two separate issues here....

1. Fuel pump relay clicking. I'd probably ignore this for now. If it runs in limp mode it's getting enough fuel to start. You need to address it but it's not critical.

2. Issue with either your crank, cam or both sensors. Whatever signal your DME is getting from the crank and cam doesn't make sense. When you pull the crank sensor connector and it only has the cam to go off, it runs.

For my money, I'd start with cam and crank sensors and go from there.
 

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Hi, guys- responding to BigBopper's post on the general forum. Not European so I don't have a lot of exposure to the M43 engine, but I did do some digging.

There are a few posts where others have reported cars running in limp mode with the crank sensor unplugged. My guess is that the motor uses the cam sensor and makes a best guess to set ignition timing. Here's a post on bimmerfest where a guy is talking about his M54 running with the crank sensor disconnected: Disconnected Crank Position Sensor, now have issues

Don't mean to challenge you, BigBopper (and thank you for your help on the other thread!) but the DME may be inferring the crank position from the cam sensor when it doesn't get a signal from the crank sensor that it believes, and running in limp mode. I'm no expert but it seems possible, especially because these motors do appear to poll all three sensors and interpret the combined signal- there's reports of people throwing crank sensor codes when their camshaft sensor was really bad, and vice versa.

You may have two separate issues here....

1. Fuel pump relay clicking. I'd probably ignore this for now. If it runs in limp mode it's getting enough fuel to start. You need to address it but it's not critical.

2. Issue with either your crank, cam or both sensors. Whatever signal your DME is getting from the crank and cam doesn't make sense. When you pull the crank sensor connector and it only has the cam to go off, it runs.

For my money, I'd start with cam and crank sensors and go from there.
This is why I posted it. To get others' input. It is perfectly possible to write the program so that it uses the the cam sensor inputs if the crankshaft sensor input is not detected. I know, for example, that this sort of arrangement is in place when brake lamp goes out. The car uses the indicator, I think, until you replace the brake lamp.
 

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This is why I posted it. To get others' input. It is perfectly possible to write the program so that it uses the the cam sensor inputs if the crankshaft sensor input is not detected. I know, for example, that this sort of arrangement is in place when brake lamp goes out. The car uses the indicator, I think, until you replace the brake lamp.
That makes sense.

So if that's what's going on here and it is possible for the car to run without the crank sensor, the most logical conclusion is that his crank sensor is sending a signal the DME can't make sense of.

  • Car runs with crank sensor disconnected.
  • Car does not run with crank sensor connected.
  • Additionally, with crank sensor connected the DME is repeatedly cutting power to the fuel pump. With it disconnected it is not.

That sounds like a bad crank sensor, or some issue in the wiring path between the DME and the crank sensor.

The fact that the car starts at all means the engine is capable of getting fuel, air and spark.
 

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That makes sense.

So if that's what's going on here and it is possible for the car to run without the crank sensor, the most logical conclusion is that his crank sensor is sending a signal the DME can't make sense of.

  • Car runs with crank sensor disconnected.
  • Car does not run with crank sensor connected.
  • Additionally, with crank sensor connected the DME is repeatedly cutting power to the fuel pump. With it disconnected it is not.

That sounds like a bad crank sensor, or some issue in the wiring path between the DME and the crank sensor.

The fact that the car starts at all means the engine is capable of getting fuel, air and spark.
It's the clacking relay that puzzles me. The OP says that the clacking stops when he unplugs the crankshaft sensor. The feed side is being pulsed. That's not the way it works. Almost as though the crankshaft signal is finding its way to the feed side of a relay. This is why I think we are looking at cable damage. Crossed wires or a problem at te DME interface.
 
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