[SI-LIST] Re: Automotive ECU EMI problems
- From: steve weir <weirsp@xxxxxxxxxx>
- To: A6intruder@xxxxxxxxxxxx, "SI-List" <si-list@xxxxxxxxxxxxx>
- Date: Tue, 13 Jul 2004 20:14:03 -0700
Dan,
Your problem is common mode noise appearing on the signal lines and/or
outer cable shield that you bring out of the enclosure, in this case the
serial port. You are either not using shielded cables, or the shields are
poor quality, or the shields are not attached to the connectors properly,
or the connector bodies on the ECU chassis are not connected to the chassis
well ( ie plastic connecctors, connectors on painted surface, etc. etc. ).
You might band-aid the problems with an ordinary clamp-on ferrite EMC
filter such as available at Radio Shack or offered by various hucksters as
the magic fuel line magnetic atomizer. A better choice is to fix the
shielding. A third alternative is to filter the signals.
I thought that altering the ECU has now been raised as a crime worse than
pirating old copies of the Rosie O'Donnell Show. Apparently, you aren't
afraid of the black ECU inspection helicopters.
Steve.
At 10:38 PM 7/13/2004 -0400, Daniel R. Nicoson wrote:
>I hope this post isn't out of place. I am part of another list (yahoo
>groups EECtuner) that uses a "piggyback" board to control our auto's ECU.
>Basically the ECU looks at any changes on the piggyback board each time it
>starts up and uses those settings to operate.
>
>Our problem appears to be some form of EMI. Several hundred of us have no
>problem but there are a small number of users that do have big problems. We
>have tried to figure it out but it appears we don't have the technical
>knowledge to solve the problem for every one's unit.
>
>The piggyback board mounts inside the OEM enclosure for the ECU (die cast
>aluminum) and cable about 5' long feeds out to a serial port connection for
>a laptop.
>
>Any laundry list of things to check that might solve the EMI problems?
>
>Several of those having problems suspect it is the cable acting as an
>antenna, problem goes away when cable disconnected (but then the device is
>unusable...). Myself and most of the group have no problems...trying to
>help the minority.
>
>Suggestions?
>
>Thank you in advance,
>
>Dan
>
>------------------------------------------------------------------
>To unsubscribe from si-list:
>si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
>
>or to administer your membership from a web page, go to:
>//www.freelists.org/webpage/si-list
>
>For help:
>si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
>List FAQ wiki page is located at:
> http://si-list.org/wiki/wiki.pl?Si-List_FAQ
>
>List technical documents are available at:
> http://www.si-list.org
>
>List archives are viewable at:
> //www.freelists.org/archives/si-list
>or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
>Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
>
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
