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RVing message boards => Tech Talk => Topic started by: LTJourney on September 23, 2009, 08:11:13 AM

Title: Cummins ISB fault code
Post by: LTJourney on September 23, 2009, 08:11:13 AM
Hi all,

We just bought a new (to us) 2002 Journey 32DL with a Cummins 300 and Allison 6 speed ~64k miles. Mid-way home from the midwest to the west coast (1900 miles) we started to get an intermittent check engine light (CEL) upon coasting downhill (but only with the exhaust brake off and foot off the gas). Twice the rig even started spewing smoke and lost all power for a few seconds. The rest of the ride home I made sure to stay on the gas or on the exhaust brake, and the light didn't return while driving.

Now whenever I start the engine, or let the rig idle after parking it the CEL will come on and when I start driving there is very little power for a few seconds. Then the light goes out and things run normally.

Now we're home and I just installed the Silverleaf VMSpc software. The code that I get for the CEL is: ENG, SID, 254, 8, Controller #1, Frequency Error. I called Cummins and they don't even list a code 254 (maybe I should have asked for code 254-8???). Does anybody have any experience with something similar, or a list of Cummins codes that may shed some light?

Thanks in advance,
Lars and Tamara
Title: Re: Cummins ISB fault code
Post by: Tom on September 23, 2009, 09:16:58 AM
Here's a link to fault codes for the ISB engine:

http://www.diesel-service-parts.com/isb-fault-codes.html

FWIW code 254 is listed for the ISM and ISX engines. Since 254 isn't listed for the ISB engine, you might want to call Martin Perlot at Silverleaf:

http://www.silverleafelectronics.com/

Edit: Looks like you posted on their forum.
Title: Re: Cummins ISB fault code
Post by: Gary RV_Wizard on September 23, 2009, 09:22:35 AM
I have a code list for the ISC & ISL engines and that has no #254 either.

Here is a link to a list of ISB codes. No #254 there either.
http://www.diesel-service-parts.com/isb-fault-codes.html

Suggest you contact the VMSpc people to see if they have any explanation of the unknown code you are getting.

Title: Re: Cummins ISB fault code
Post by: mayfair on September 23, 2009, 10:13:42 AM
It's a longshot - but here ya go

First let me state that I don't know JACK about motor homes, but Cummins engines in Dodges I AM familiar with. Assuming that a Cummins is a Cummins no matter WHERE it's installed I'll give you a suggestion

A friend of mine has I think it's a 2004 Dodge Ram with the Cummins engine and it was doing the same exact thing that you describe. After hours and hours of trying to figure out what it was it turned out to be a wire near the A/C compressor that had rubbed through the insulation and was intermittently grounding itself out. He couldn't see it right away because it was only a small area and it was obviously on the bottom side. Once repaired, the problem was gone.

If you are at all interested in this theory, I can find out a little more to the story specifically which wire it was. It was a year or so ago and I've since forgotten.

Let me know ... good luck !!
Title: Re: Cummins ISB fault code
Post by: BernieD on September 23, 2009, 01:47:57 PM
Lars

A type of mistake most of us make at one time or another is: Did you set the Silverleaf for the correct engine ???
Title: Re: Cummins ISB fault code
Post by: Tom on September 23, 2009, 05:15:54 PM
Bernie,

I've never made that mistake  :-[
Title: Re: Cummins ISB fault code
Post by: LTJourney on September 23, 2009, 07:27:47 PM
Thanks for the fault codes.  And I'll check the wiring for chafing as well.  I double checked that the software was programmed for the right engine (and that mine is indeed the ISB), and indeed it is all true and correct.

I don't understand why the 254 code is not on the code lists, but Martin Perlot of Silverleaf responded that the 254 code means BAD ECM :'(.  For the specific 254-8 code I will need to speak with Cummins directly, and let them know it's a J1587 code. 

I now have mixed emotions - "Woohoo I know what the code means!", then very shortly thereafter: "Dang, it's the ECM!"

I've heard that chafing wiring can cause ECM woes so I'll chase that avenue first...

Thanks again and I'll let you know the final verdict.

Lars
Title: Re: Cummins ISB fault code
Post by: mayfair on September 23, 2009, 11:55:48 PM
Good luck !!

If you need / want me to chase down the fella who had the problem for more info, let me know.
Title: Re: Cummins ISB fault code
Post by: Gary RV_Wizard on September 24, 2009, 11:26:08 AM
ECMs themselves very rarely fail. Trust me - I worked several years with the auto & engine companies worldwide as a computer consultant to develop ways to diagnose ECM problems in the field and all the manufacturers pretty much concluded the ECM is almost never the problem. It is wiring, connectors, and sensors & activators that feed the ECM (in that order too). So don't rush off to replace that expensive box quite yet.

All ISBs are not alike - the ECM programming in the Dodge Truck version is not the same as in motorhomes and the fault code list is different.
Title: Re: Cummins ISB fault code
Post by: mayfair on September 24, 2009, 11:33:53 AM

All ISBs are not alike - the ECM programming in the Dodge Truck version is not the same as in motorhomes and the fault code list is different.


I agree 1000%, however some of the things that cause the problems could be similar ( chaffed wire, bad sensor, etc )