Check Engine Light

[thomasgibbens]

I recently had a check engine light on my dash. I have the Silverleaf Electronics display so I checked it and it said Fault code 641-9, VGT Temp-Driver-Update.  It has been intermittent and didn’t occur again for about 20 hours of driving. So I went to a Cummins Shop and after 4hours of diagnosis(about $700), they said they couldn’t find anything, but they said it could be a loose connection or a wire shorting against some metal or several other things. Their recommendation was to replace the wiring harness which was estimated to be about $5000 installed!  They said I could just monitor it but they said to get it taken care of. Has anyone run across this issue and if so, how was it resolved?  I have driven a couple of days since and no warning lights have come up. This is a ISX-600 Cummins in a 2015 Dynasty. Hope I have given enough information. 
 

Tom Gibbens

’15 Dynasty 

[DavidL]

18 minutes ago, thomasgibbens said:

I recently had a check engine light on my dash. I have the Silverleaf Electronics display so I checked it and it said Fault code 641-9, VGT Temp-Driver-Update.  It has been intermittent and didn’t occur again for about 20 hours of driving. So I went to a Cummins Shop and after 4hours of diagnosis(about $700), they said they couldn’t find anything, but they said it could be a loose connection or a wire shorting against some metal or several other things. Their recommendation was to replace the wiring harness which was estimated to be about $5000 installed!  They said I could just monitor it but they said to get it taken care of. Has anyone run across this issue and if so, how was it resolved?  I have driven a couple of days since and no warning lights have come up. This is a ISX-600 Cummins in a 2015 Dynasty. Hope I have given enough information. 
 

Tom Gibbens

’15 Dynasty 

That's a classic Cummins Shop story.

Charge diagnostics and not provide a diagnostic.

Replace a way overpriced wiring harness.

I would diagnose the wiring issue by using a schematic.  Replace only the wires that check shorted or open.

Just disconnect the wire at both ends (according to the schematic) and test.  Just run a pair of wires parallel to the old harness and connect the sensor back up to where it's supposed to be.

About a few hours of work.  Save $5K.

 

Edited July 21, 2023 by DavidL

[vito.a]

I would wait until (or IF) it really becomes a problem.  Right now, they are guessing.  And they could induce more problems when they replace that wiring harness. 

Enjoy your coach!

[96 EVO]

My God!

Spend 5G on something that may fix your issue, or may not 🤔!

Is it just me, or are Cummins shop's getting stupider every day? 

[Guest Ray Davis]

The warning light has become somewhat of a joke.  I wish I had a nickel for everyone I've heard of coming on for no discernable reason.  Mine has come on a time or two over the yrs.    It has come on in a downpour so it doesn't take much.      Now, if the red stop engine light comes on I would absolutely see why.     

39 minutes ago, 96 EVO said:

Is it just me, or are Cummins shop's getting stupider every day?

They think you have a lot of money and they want it.   😁

It seems to me there was a significant change when they started calling themselves TECHs instead of mechanics.  Of course, that's probably about the time the engines became electronic.  The mechanics sold their tools, retired & bought a MOHO.   LOL   🛠️

[96 EVO]

9 minutes ago, Ray Davis said:

  

They think you have a lot of money and they want it.   😁

 

Plenty of businesses & politicians more than happy too part you from every Nickel you have!!  

[philcarrell]

 VGT Temp-Driver-Update fault code you posted is referring to the turbo charger.  Don't know if they have updates are not.  If you have good turbo boost I would say drive on.  However I would think Cummins would have pulled the turbo actuator off and checked it in the 4 hours they were trouble shooting.  Of course the techs nowadays overlook the obvious when trying to troubleshoot intermittent problems 

[OhReally]

Tom, just a comment about your dash light.

SilverLeaf, like any other diagnostic system, is at the mercy of small system signals that may go high or low for many reasons. The dash light comes on when any signal is "out of limits" per the diagnostic system designer. Any diagnostic system will act on this momentary out of limits signal and try to determine where the signal originated. That is a difficult thing to do and will often result in multiple different codes that suggest a problem in components that are operating just fine. That is (unfortunately) normal given that any diagnostic system only approaches 100% capability and accuracy. I recently received three different codes on my SilverLeaf when an oil pressure sender failed. Two of the three codes were unrelated to the oil pressure sender and no problems existed in those other components.

Watch for any new codes in your SilverLeaf history and like Vito said, enjoy your coach.

[SoDakLou]

57 minutes ago, Ray Davis said:

red stop engine light

What would you look for if this light came on?

[jacwjames]

I would stop ASAP.

Then pull up the diagnostic on the Silverleaf to see what codes are recorded.

Then go to the Cummins Quickerve site and see what the code is and how to troubleshoot.  Quickserve has a fault code lookup, very easy to use.  I will provide an initial document that explains the code and some info on how to trouble shoot BUT within this document there will be links to other documents that provide a step by step procedure on how to troubleshoot. 

Depending on what is wrong I would fix or call for a tow to the nearest shop that could fix the problem. 

[Tom Cherry]

Couple of comments as a "member" and a "reminder" as a moderator....

FIRST.  All the comments are great.  I don't pretend to be the expert on the codes and we have a LOT of folks that understand the Cummin's Diagnostic software and have performed complex engine repairs....probably better than a LOT of Cummins's techs.  SAD but true.  

SECOND....Jim J and I usually agree on so much stuff that it is spooky.  However, we have had at least one or two cases where a simple repair that SHOULD have been made in the field but since ONE HAS COACHNET and the towing is FREE....resulted in the destruction of a very nice MH.  Towing, for me, will be the last option....  A Mobile Repair tech, from a Cummins Certified Shop (and I know all the wise cracks and such that brings....so spare us...) might be, in the long run....CHEAPER.  A simple hose that came loose and would have take maybe 10 minutes of just "LOOKING UP THERE" or having a knowledgeable tech out....OF COURSE with his Laptop and Insight (?) Cummins diagnostic software would have been maybe $200.  Coachnet sent out Cowboy Bill and his RIG....with NO CLUE...so the poor MH was towed and DROPPED THREE TIMES....yes TRES... the damage was upwards of $75K and it took a LONG time for Coachnet and their "certified towing contractor" and their insurance policies and a few lawyers thrown in, just to make it interesting....to finally get it resolved.  In the end the repairs were made....but there were some issues that were never quite "right" and the member traded it off.

THAT is, hopefully, a ONE OFF and really freak and extreme situation.  There have been many posts here about what a knowledgeable owner needs to know and the information (weights and measurements) that is needed to tell a competent Tow Truck service is needed....BEFORE they send out the RIG....and if they don't have a CLUE....SAY GOODBYE and get Coachnet back on the phone.  Likewise, the good ones appreciate this.  We have also had horror stories of using bailing wire to tie up the Driveshaft or not bagging the parts used to disconnect or whatever and that damage was in the thousands as the driveshaft "done fell down" and sparked and arced all the way.

The final comment....and let's not let this one morph and get out of control...  We probably have had enough of the good natured kidding of techs, politicians and I threw in a lawyer, as I raised one and am proud of his accomplishments. SO, please refrain from taking that a bit further down the road where it gets testy and it violates our NON POLITICAL (as well as Religious...and whatever) charter; THEN we have to hide threads or edit or warn and such.

Thanks in advance....

[jacwjames]

Tom,

I made a mistake in assuming that everyone on the forum is capable of fixing stuff.  I know that a lot of people are very capable but there are some that aren't.  I have a friend who is very smart, former University Professor, but when it comes to fixing stuff he has minimal success and calls me, and I may be able to help him over the phone and if not I jump in a car and head that way. 

So I guess my answer was geared more toward the DYIer who could fix the simple to moderately difficult problems.  I have a fairly decent maintenance background so I'm not afraid to tackle problems.  But I have had 3 instances where I've had to be towed.

1. My Class C developed a severe transmission leak at the output seal.  When I first noticed it we were ~150 miles from home, we had stopped to give the dogs a break and part of my routine was to do a walk around including taking a glance under the motor home.  Looked under and saw a pretty constant drip, told my wife we had to turn around, stopped after ~50 miles and took another look, by that time it became a pretty good stream.  Ain't driving it anymore so called for a tow and arranged for the mechanic I use to take a look.  He pulled the tranny and only found the output seal bad.  This was on a Ford Chassis, he recieved a new seal and within the box it had a WARNING>original seal was not for HD applications.  Huh!!.
2. Monaco Windsor  My wife was getting ready to head out on a trip and I was getting ready to head to Spain for business.  I was helping hook up the Jeep, got back in the coach and no power at dash and cat eyes on the shifter.  I spend a day checking everything I could find as a possible cause.  Called the local Cummins shop, the would not sent out a tech saying they were short handed, no other options but to call for a tow.  They ended up diagnosing the TCM and had we decided to replace since my wife had the trip arranged. 
3. Monaco Windsor   Driving I-40 east I got an alarm on the Silverleaf but no lights on dash, pulled into a Cracker Barrel to check things out thinking it wasn't bad and immediately saw coolant coming out below the radiator.  Flashlight in hand crawled under an saw the radiator had multiple punctures, road debris took out the radiator, not driving anywhere.  So called for another tow. 

Luckily all 3 tows were uneventful.  Even got to rid in the tow truck 2 times.  The first time was with the Class C, the driver knew what he was doing but he drove pretty fast, I guess since it was a smaller RV.  The second time was in the Windsor with the radiator problem.  This driver did everything right from tieing up the mud flat, pulling the driveshaft, hooking up air and check all was good.  He drove at a slower speed, knew every bump in the road and would change lanes as necessary. 

I know there are far more skilled people on the forum, I consider myself above average and can figure stuff out and ain't afraid of getting dirty.  I think I could fix most of the things a mobile tech could fix unless it requires the INSITE computer and or major surgery.   I would be able to make that determination pretty quick and make the decision to fix or tow. 

So I guess my answer should have had the qualifier  >>>>  It Depends On Whether You Can Fix Stuff!!! 

[Tom Cherry]

@jacwjames & @Dr4Film

Jim, thanks.  My comments were just mine and not any criticism or such...and the comments about the "folks that fix" MH's have been know to deteriorate rapidly.

Here is a post that I have often copied and used...the source is Richard or our DR4Film.  It has been used by others with more info and such.  We have a BUNCH of good info if you search "Tow Information" and select TOPICS....so here is what every one should know...before they let the "Monsterous Recovery Vehicle Technician" start to work...especially if he/she utters..."DAD GUM...Ain't never seen one like this befur..." comment(s)

IF the carriers don’t handle Class A, throw them out.  Demand a LOW BOY trailer for transport….. Richard’ post follows….

I started with Coach-Net back in 2010 prior to leaving CA and traveling full-time. I am still with them and will not switch to any other ERS. I have had three different tows, one in Oregon, One on the Cassier Highway in northern British Columbia and one on I-81 in Virginia. Each time the tow company had to bring two trucks, one for the coach and one for my 30 foot cargo trailer I was towing at the time. The tow in northern BC would have cost me close to $7000 as it was over 200 miles one way. It only cost me a signature.

They have always dispatched the proper equipment to handle the job safely without causing any damage.I have put together a list of critical information needed whenever I have had to call them for a tow.  Here is the list below for my coach - 2002 Windsor.

Towing Information for Towing Company

Length of Coach = 41 Feet

Width of Coach = 108 inches

Weight of Coach = 36,000 lbs

Rating of Front Axle = 13,000 lbs

Rating of Rear Axle = 23,000 lbs

Total Weight Coach and Trailer = 48,000 lbs

Height of Coach = 12 Foot

Type of Suspension = Air Bag

How many Air Bags = 8 – 2 on each Wheel - Outboard

Front Cap Slide or No Slide = Front Cap Generator Slide

Transmission Model Number = Allison 3000MH

Distance from Front Cap to Front Axle = 96 inches

Clearance from Ground to Bottom of Coach = Varies

[DavidL]

1 hour ago, jacwjames said:

Tom,

I made a mistake in assuming that everyone on the forum is capable of fixing stuff.  I know that a lot of people are very capable but there are some that aren't.  I have a friend who is very smart, former University Professor, but when it comes to fixing stuff he has minimal success and calls me, and I may be able to help him over the phone and if not I jump in a car and head that way. 

So I guess my answer was geared more toward the DYIer who could fix the simple to moderately difficult problems.  I have a fairly decent maintenance background so I'm not afraid to tackle problems.  But I have had 3 instances where I've had to be towed.

1. My Class C developed a severe transmission leak at the output seal.  When I first noticed it we were ~150 miles from home, we had stopped to give the dogs a break and part of my routine was to do a walk around including taking a glance under the motor home.  Looked under and saw a pretty constant drip, told my wife we had to turn around, stopped after ~50 miles and took another look, by that time it became a pretty good stream.  Ain't driving it anymore so called for a tow and arranged for the mechanic I use to take a look.  He pulled the tranny and only found the output seal bad.  This was on a Ford Chassis, he recieved a new seal and within the box it had a WARNING>original seal was not for HD applications.  Huh!!.
2. Monaco Windsor  My wife was getting ready to head out on a trip and I was getting ready to head to Spain for business.  I was helping hook up the Jeep, got back in the coach and no power at dash and cat eyes on the shifter.  I spend a day checking everything I could find as a possible cause.  Called the local Cummins shop, the would not sent out a tech saying they were short handed, no other options but to call for a tow.  They ended up diagnosing the TCM and had we decided to replace since my wife had the trip arranged. 
3. Monaco Windsor   Driving I-40 east I got an alarm on the Silverleaf but no lights on dash, pulled into a Cracker Barrel to check things out thinking it wasn't bad and immediately saw coolant coming out below the radiator.  Flashlight in hand crawled under an saw the radiator had multiple punctures, road debris took out the radiator, not driving anywhere.  So called for another tow. 

Luckily all 3 tows were uneventful.  Even got to rid in the tow truck 2 times.  The first time was with the Class C, the driver knew what he was doing but he drove pretty fast, I guess since it was a smaller RV.  The second time was in the Windsor with the radiator problem.  This driver did everything right from tieing up the mud flat, pulling the driveshaft, hooking up air and check all was good.  He drove at a slower speed, knew every bump in the road and would change lanes as necessary. 

I know there are far more skilled people on the forum, I consider myself above average and can figure stuff out and ain't afraid of getting dirty.  I think I could fix most of the things a mobile tech could fix unless it requires the INSITE computer and or major surgery.   I would be able to make that determination pretty quick and make the decision to fix or tow. 

So I guess my answer should have had the qualifier  >>>>  It Depends On Whether You Can Fix Stuff!!! 

The GREAT majority of folks on just about any forum don't have the background to diagnose and repair the type of issue the OP speaks of.

Heck, seems Cummins isn't capable either....(geees).  Might as well just remove the radiator cap, roll a new RV underneath and call it fixed...

As far as ignoring DTCs....as a general statement, that's not a wise move.  They are there for a reason.  And can be frustrating as they are real time monitoring voltages and signals going across different ECUs on the vehicle data buss.  Intermittent connections, water intrusion, salt, corrosion, bad grounds, and fluky electronics all contribute to intermittents which can be frustrating.

BTW, the "Silverleaf" is reporting powertrain issues.  It's not generally creating them.  It just listens and talks on the vehicle data buss for DTC issues and reports back to you for ease of use.   It's a mini scan tool.  It has it's own set of diagnostics and reporting, but those aren't powertrain, and those shouldn't be triggering Check Engine or Power Loss idiot lights (that's against Fed Emissions Law).

Best is to find someone local that has high diagnostic ability (industry calls these 'Diagnostic A Tech").  Most are found in Auto as there is far more volume of work, issues and experts.  They generally all work similar, the process for diagnosis is same.  And yes, there are tricks and experiences that working on same vehicle certainly helps...but with a good DTC, and a schematic and general understanding of the system, it's fixable without replacing an overpriced and unneeded wiring harness.  And yes, those folks are the highest per hour paid of all Auto / Truck / RV techs.

 

Edited July 22, 2023 by DavidL

[dl_racing427]

On 7/21/2023 at 7:33 PM, DavidL said:

That's a classic Cummins Shop story.

Charge diagnostics and not provide a diagnostic.

Replace a way overpriced wiring harness.

I would diagnose the wiring issue by using a schematic.  Replace only the wires that check shorted or open.

Just disconnect the wire at both ends (according to the schematic) and test.  Just run a pair of wires parallel to the old harness and connect the sensor back up to where it's supposed to be.

About a few hours of work.  Save $5K.

Agreed, though it's going to be difficult to ID the problem when it's intermittent.
It doesn't appear to be something that's going to strand you.  I'd wait and see if it reappears and becomes consistent, so you have a good chance of finding the wiring issue.

 

[Scotty Hutto]

From the “For What It’s Worth” department…

My DW’s family owns one of the largest big vehicle towing services in the Southeastern US, Simmons Wrecker in Meridian, MS (shameless plug). My brother-in-law has been in the towing business almost 50 years, and my father-in-law (God rest his soul) was in it over 60 years. All of which qualifies me to say “I know a guy…” 😂

Ricky and I have had many conversations about towing motorhomes. The short answer is motorhomes (more specifically the frames) aren’t designed to be “towed”. He purchased a “bus carrier” (basically a specialized lowboy flatbed with winches and such), and uses that exclusively to “tow” motorhomes. 

His advice is fix it onsite if you can. (Yourself or mobile tech) It will almost always be cheaper.  But some things can’t be fixed on the side of the road. If you can’t fix it, make sure you find someone that knows what they’re doing towing a motorhome.

He told me (and I quote), “ I don’t even answer the phone for Good Sam.  They beat you (the towing company) down on price, then don’t pay on time. CoachNet is very fair and pays on time.”

[96 EVO]

15 minutes ago, Scotty Hutto said:

 

He told me (and I quote), “ I don’t even answer the phone for Good Sam.  They beat you (the towing company) down on price, then don’t pay on time. CoachNet is very fair and pays on time.”

Wonder how widespread that is around the continent 🤔?

Mine is up for renewal next month.

[Scotty Hutto]

I only have that one data point.  It would be useful to find out, tho!