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Topic: Cleaning ECM connections to correct bad data issues (Read 857 times) previous topic - next topic

Cleaning ECM connections to correct bad data issues

My VMSPC is seeing a lot of bad data coming from the ECM.  There are no engine performance symptoms but certain VMSPC gauges, like odometers & tank minders, are not working.  Others, like RMPS & temps are working fine.  I spoke with Art at Silverleaf and he says that less than 1% bad data, as reported under the VMSPC Advanced tab, is normal.  He says they can deal with up to about 20%.  Mine is running at 30%.  He suggests checking all connections at the ECM.

I plan to check the ground wire at the ECM and disconnect, clean & grease both plugs at the ECM.  Is there anywhere else in the system, other than the plug under the dash, that should also be checked?

Re: Cleaning ECM connections to correct bad data issues

Reply #1 –
Good idea, but go carefully on 21 year old connectors and wire.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Cleaning ECM connections to correct bad data issues

Reply #2 –
Our Allison ECM has several long plugs. And each of these plugs have dozens of small wires, each with a single metal termination connection that also pulls out of the back of the big plug. All places for problems which need to be checked.

Re: Cleaning ECM connections to correct bad data issues

Reply #3 –
Good advice from Bruce, wires and connectors can be brittle.  Use a electrical contact spray cleaner.  It is just as often the connection between the wires and the connectors as the connectors or a bad or frayed wire so look carefully.  You can use a dielectric grease to waterproof the plug.

Bad data especially for miles that are used in the trip odometers and the tank minder seem to be pretty common for our older coaches.  VMSpc is just seeing what is reported and trying to use that.  There is almost no error checking at the source and the reporting rates on the older data bus protocols are slower.  This makes trying to read many data points, smooth out the curve and throw away the outliers pretty hard especially if you see lots of bad reports in a row.

The newer coaches have a much faster reporting speed and the latest hardware from Silverleaf is able to read the faster rates. It is not retroactive.

Let us know how this goes and if it helps. 

Roger

Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Cleaning ECM connections to correct bad data issues

Reply #4 –
Anyone know how to remove these ECM connectors?  I was expecting to see a bolt through the middle but there's nothing obvious holding it.  It feels very solid.  Does it snap in place?

Re: Cleaning ECM connections to correct bad data issues

Reply #5 –
Quote from: bdale –
Anyone know how to remove these ECM connectors?  I was expecting to see a bolt through the middle but there's nothing obvious holding it.  It feels very solid.  Does it snap in place?
Bumping this back up in case someone today might know the answer.  From everything I've found online, the entire yellow connector should pull straight away from the ECM, towards the side of the coach.  But, all of the ones I've found have a bolt through the center that I don't have.  It seems like it has to be simple but I stopped pulling & very light prying for fear of breaking something.

Re: Cleaning ECM connections to correct bad data issues

Reply #6 –
Have you asked Dave Atherton? I would shoot him a picture and ask him.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Cleaning ECM connections to correct bad data issues

Reply #7 –
Quote from: bdale –
Anyone know how to remove these ECM connectors?  I was expecting to see a bolt through the middle but there's nothing obvious holding it.  It feels very solid.  Does it snap in place?
Is there a bolt on the other end of the connector?
Tim Dianics
Pam Sapienza
Vader PupZilla Labrador Canine Beast (AKA Pup)
Columbia, MO
1996 U320 4000
2021 Jeep Gladiator, Diesel
 

Re: Cleaning ECM connections to correct bad data issues

Reply #8 –
Quote from: TGordon –
Is there a bolt on the other end of the connector?
Contacted Dave Atherton as Brett suggested.  He was going to diagnose the problem a few days ago when we were coincidentally in Custer,  SD. Unfortunately he had to cancel due to an emergency of some kind.  He did tell me that there is an Allen screw holding the plug in place bit didn't recommend removing it.  I'm not going to risk it while on the road.