For 5 years I used a VMSpc serial to USB product. I recently upgraded to the VMSpc USB product. Nothing else changed and I am using it with the same Windows 7 Laptop. Cruise set speed will only show the set speed occasionally. I can find no pattern of timing when it will show, or how long the set speed will be indicated. When the set speed is not shown, I only see ‘0'. So what is the problem? Rex Darley

Hmm.. That make this a J1708/J1587 Only Coach, as far as the VMSpc is concerned.. I don't know why this would be different, between VMSpc Models, but if there was Engine Work done, I would not be surprised with this change.. It would be helpful to have a RAW Engine Log sent to us.. Please create one by Selection the "Raw Log" menu option on the Advanced Menu.

Hi Rex, I have been using VMSpc on my 03 Dynasty (ISL400) for about 8 years... before that on my Diplomat (ISC). I suspect that the Monaco/Cummins diag plugs are the same. Occasionally the Cruise set speed reading goes to "0", then comes back to the correct value in less than a minute. Nothing functionally changes so I suspect there's a bug somewhere... (not wanting to place blame anywhere). It looks like the Cruise Set Speed PID code (86) or its value either gets missed or perhaps loses a bit somewhere. I've considered it an annoyance ... wondering if there's something with the Cummins-to-VMSpc interfacing since I've only heard of it with those engines.

Submitted by larrycad on Thu, 2013-01-17 18:33


I have a cummins ISC 8.3, 315hp and I have had this same problem since I installed VMSpc. Has anything changed or is this still a problem? I would really like to have consistent and reliable cruise information.

I was looking, but I don't believe I have received any Raw Logs from Rex Darley. If you would like to Capture a Raw Log and send it to me, that would be very helpful.. Mark Overholser =================================================================== Mark D. Overholser Engineering Technician SilverLeaf Electronics Inc. 2472 Ferry Street SW Albany, OR 97322 888-741-0259 541-967-8111 541-967-8988 (fax)

Submitted by on Tue, 2013-02-12 09:19


I have a 2003 Alpine Coach with a Cummins ISL 400HP (6-Pin Diagnostic Plug) and have experienced an intermittent cruise control display since the VMSpc was installed. I will not have access to my coach until late March but can provide a raw log if still necessary at that time. I'll keep checking status.

Submitted by mwassing on Tue, 2013-06-11 16:16


I have this same problem with my 2004 HR Endeavor. I sent you a rawlog on Sunday June 8, 2013. Did you receive the E-mail and were you able to open the Rawlog. I hope this info will help to resolve this problem. I have a cummins 330hp with an allison 300mh tranny. I have a additional problem of my max rpm always reading in excess of 3000rpm.

Submitted by mwassing on Mon, 2013-08-12 09:27


Anything new on this problem? I sent you the raw log about 7 weeks ago. The boss should be back from the Summer FMCA by now. No word on the cruise set problem or the max rpm problem. Any help would be nice.

Submitted by larrycad on Tue, 2015-04-07 20:41


Since my 2000 American coach, ISC 315 hp does the same thing, i.e. reads "0" most of the time and randomly reads cruise set speed, I have been watching this thread for a couple of years to see the solution. So far, nothing. I downloaded the latest release and installed it but no change.

Submitted by walt2137 on Wed, 2015-04-08 19:18


Well it's to late to be of help to my good friend Rex Darley as he passed last year but I hope you guys get a fix, I never had that problem with my old serial VMSPc that I bought in 01 and I used it on a 99 ISB Cummins and a ISC 350. Walt

Submitted by Art on Fri, 2015-04-10 12:12


Hey fellas...Art here... I see this is an ongong issue with many ISC engines. My feeling (without solid data to back it up) is that some of the fixes we built into v3.x software broke this function. Most of those fixes were for the prolific ISL. Here at VMSpc v2.5b10c this link you'll find the earlier program common to the serial-jib [Walt ;-) ] Its a complete package but for drivers. Keep your old drivers installed. When it prompts you for the Install Directory, remember: its defaulting to "VMSPC" unless you rename it. If you don't change it, it Will overwrite your original. Do rename it. Give it something like 'VMSpc 2.5' Then, after it finishes, copy your trips and SCReen (guages) files over to the new 2.5 directory from the original directory you've been working from; likely C:\VMSPC. Once installed, it will look much like the v.3x We've had some issues with fuel, cruise and tank minder levels. Hope this helps! Art Documentation Central Silverleaf Electronics (888) 741-0259 (US) or (541) 967-8111 (Everywhere else)