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E36 (1991 - 1999)
The E36 chassis 3-Series BMW was a huge hit among driving enthusiasts from the first moment the car hit the pavement. The E36 won numerous awards over the years it was produced and is still a favorite of many BMW enthusiasts to this day! -- View the E36 Wiki

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Old 01-18-2013, 11:46 PM
albinomidget albinomidget is offline
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Location: Rapid City, SD
Join Date: Nov 2005
Posts: 31
Mein Auto: '98 E36 M3 Sedan
It won't start!

I originally posted this on the M3 forum but was told to post here so more folks would see it.

Now that I understand a little more about my problem I'm not sure where to begin troubleshooting it. The history is this:

My '98 BMW M3 quit starting in the fall. It wouldn't turn the starter. All instrument lights would light and I could pop the clutch to start the car. The key would no longer stop the car either. I would stop the car by killing the motor with the clutch.

I suspected it was a bad ignition switch so I bought a new one and tried to install it. When I had it apart I found that the new switch would not start the car either. I put the old switch back in since I thought this was not the problem and all of a sudden the key started working again and would turn the starter over every time.

It worked for about 2 months and then it left me stranded at work. It was very cold in Minneapolis that evening and I tried to pull it around the parking lot to pop the clutch but I suspected it was just too cold.

It almost seems like the EWS is locking it out but I was also told that it could be the crankshaft position sensor or the cam shaft position sensor.

Why would any of those sensors relate to this problem?
Since the key will not turn off the car as well, is this a clue that leads to something in particular that is the problem?
I see quite a few things wired into the EWS in my Bentley manual. How would I determine if one of these devices or the EWS itself is defective?
It shows the EWS located behind the glove box. Is this a hard device to access?
Could this be a case where there is an open circuit somewhere in the wiring? If so what is the best way to determine where that is?
It shows a diagnostic coding input on the EWS in my Bentley manual. What hardware is required to communicate to the EWS?
What information can I find out by plugging into the device?
Do I have to access the EWS module to hook up to this communication port or is access in another location on the car?

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Old 01-19-2013, 12:03 AM
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hornhospital hornhospital is offline
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Mein Auto: E24x2,E36x1,E30x1, F150
If the key will not turn the engine OFF, it's not the EWS. I think you have problems with the link between the key tumbler and the switch. That piece can break but still function for a while. Pull the tumbler and try to turn the link with needle nose pliers (odd-shaped pin-like thingy in the recess behind the tumbler).
If that's what the problem turns out to be, you'll have to buy the whole column lock. You can't buy the link by itself.
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Last edited by hornhospital; 01-19-2013 at 12:05 AM.
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Old 01-27-2013, 06:10 PM
albinomidget albinomidget is offline
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Location: Rapid City, SD
Join Date: Nov 2005
Posts: 31
Mein Auto: '98 E36 M3 Sedan
Thanks for the response Hornhospital.

So get this... I took the dash all apart to access the EWS since I didn't know exactly where it was or what module it was under there. The only way I found it was by carefully following the wiring diagram... see attached schematic out of the Bentley manual.

I found the green/black wiring coming from the ignition switch to the EWS and the black/yellow wire coming out of the EWS and going out to the starter. I unhooked the harness from the EWS and made my own temporary jumper wire and installed it across these 2 wires.

To my amazement the thing started to turn over. I turned it over a couple times and my battery seemed to be low on juice since it has sat in the cold for so long. I took another vehicle and jumped the E36 M3. I had plenty of juice to crank the starter.

I cranked and cranked and the thing would not fire. This is very odd since the thing usually fires right up even in the coldest of weather. Now I'm beginning to wonder if the EWS also locks out the ignition so that the plugs will not get spark. I decided to take a break and do a little more research.

Could the EWS lock out the ignition so that no current is supplied to the spark plugs???

Thanks for your help,

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Old 01-27-2013, 08:38 PM
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BMR_LVR BMR_LVR is offline
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Location: Asheboro, NC
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Mein Auto: 1992 525i
I'm pretty sure that, if the EWS was at fault, it would not run at all. It not only disables the starter, but the fuel and ignition as well. If you could bump start your car, then it's not the EWS. Just think about it. If it was designed that way, all a theif would have to do is bump start the car.

I would recommend putting the wires back as they were and look elsewhere.
Most problems are usually something simple !

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It's Deja Poo - as in, I've heard this **** before.

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