Current ramping coils?

Rudy Technician California Posted   Latest   Edited  
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2013 BMW 335i xDrive 3.0L (N55B30A) 6-spd (GA6HP19Z) — WBAKF9C50DE860019
Misfire

Has anyone current ramped all of the coils at once on one of these? 

Between Alldata and Idfix, it appears as if the coils are powered directly from the DME. Is this correct? If not where are you connecting your probe?

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Phillip Diagnostician
Alaska
Phillip Default
 

I believe their is a splice that you can get to but I can't remember. But if you can get to all the wires I would believe you can do all the wires at once in your amp clamp. That's how I do the GM when their is 2 fuse for injectors or coil banks.

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Eric Technical Support Specialist
California
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Rudy, Fuse 01 in the Electronics Box near the DME ( A8681 is it's designation) is the supply for the ignition circuits. Regards, Eric …

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Stuart Mobile Technician
Illinois
Stuart Default
 

That's where I go also

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Rudy Technician
California
Rudy Default
   

Eric- When I looked at the wiring diagram it shows the coils connected directly to the DME with no fuse or anything. However as I mentioned above, my diagrams were aftermarket. I assume you have access to the OE diagram, does it show that fuse?

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Eric Technical Support Specialist
California
Eric Default
 

Rudy, Yes , the diagram shows the fuse 01 and 02 being powered by the K6341 relay. F01 is the supply voltage for the Ignition circuit through the DME (pin 10 X60001). Fuse 02 is the supply voltage for the injection circuit. I can share some detail with you directly. Send me an email tomorrow : …

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Richard Technician
New York
Richard Default
 

You can remove the engine cover and go to the yellow wire around the 3 and 4 cylinders and get all the coils right there.

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Rudy Technician
California
Rudy Default
 

Richard- This engine has ducting and other items over it. It isn't like older bimmers with just a cover and 4 bolts.I was trying to avoid taking it apart. Guess it's unavoidable....

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Richard Technician
New York
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That stuff comes apart in like 4 minutes. A couple of 8 mm bolt and 3 or 4 5mm allen heads and the valve cover and wiring is exposed. If I can do it, so can you. :) Here is a screenshot I did a couple weeks ago. The issue was miss on cylinder 1. I got coil currents at the ORANGE wire. I guess my memory slipped on the wire color before. Hope you have a nice thanksgiving.

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Ward Technician
Saskatchewan
Ward Default
 

Hello Rudy! One of the first things I ever captured when I first got my PICO. Not a 6 at once, I just amp clamped the wires to the individual coils, Good coil VS. bad coil sorted out very quickly. When I put the fuel injection system in my truck (MegaSquirt) The coils and injectors Have two injectors to a breaker and two coils to a breaker, for a total of eight wires feeding B+ to them. I have a…

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Justin Technical Support Specialist
California
Justin Default
 

Rudy, In my experience, for what its worth, I find it easier and cleaner to scope both primary ignition current and voltage at the coil activation wires. In this case the white wires from the DME to the ignition coils. I can't give you a solid reason as to why current ramping and primary voltage on the common 87 circuit is not as clean other than it has a lot of "traffic" happening on it…

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Hophy Diagnostician
China
Hophy Default
 

Hi Justin, good idea to clamp 4 wires to capture current to…ther. By the way, could you attach the pico files, it is a good example.

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Justin Technical Support Specialist
California
Justin Default
 

Unfortunately both of those captures show misfires. The primary voltage patterns are bad. Since they are bad captures I don't have the psd file, only the screen captures. :-(

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Thomas Technician
Virginia
Thomas Default
   

Brandon Stickler did a video on the Trained By Techs youtube channel about current ramping all coils on a E series. However it is the N54 not N55

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Rudy Technician
California
Rudy Resolution
   

Thanks to Eric I did find the correct fuse,however if someone can point out on this diagram what symbol indicates there IS a fuse,it would be helpful to myself and others: ***BTW the issue was a bad injector***

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Eric Technical Support Specialist
California
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Rudy, U_IGN<1 is the "path designation" on the supply wires to the coils from the DME. U=supply voltage IGN= ignition circuits <1= Fuse origin. So, if you select the diagram for Supply voltage to the DME, You will see the Fuse 1 as an input and it carries the same IGN designation. An understanding of the DIN system and how each German manufacturer applies it to the diagrams is very…

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Rudy Technician
California
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Invaluable!! Thank you very much.

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