Dash Gauges Erratic

[Brett63]

Ok, all of my dash gauges have started constant sweeping except the fuel and air. With that, I have a check trans, check engine and ABS light and a flashing lost ECU comms. I have an Acoms system and can hook up to see what is going on, but ECU or nothing is detected.

My question is, who would this be a repair for? The engine starts and runs fine, so I doubt it's a Cummins repair, the trans shifts both forward and reverse, so doubt it is an Allison issue. Are we then defaulting to an RV service center? We are about 20 miles N of Tampa. I don't even know where to take it to try and figure out what is going on, but I know there is a loss of comms on the J1939 line between the Engine and the gauge cluster somewhere.

09 Monaco Signature

[Dr4Film]

Brett, is there a hatch on the top of your dash to access the instrument cluster? There may be a way to reboot the computer that drives the instruments back there, I really don't know.

You may want to send a PM to Frank McElroy who has a lot of knowledge in this area.

Frank McElroy - Bill D’s Monacoers

Edited July 16, 2022 by Dr4Film

[Jim Pratten]

37 minutes ago, Dr4Film said:

There may be a way to reboot the computer that drives the instruments back there, i really don't know.

Reboot the computer, that’s what I’d try first also.  Simplest way is remove your negative cable for a couple minutes at your chassis batteries. Good luck!

[Tom Cherry]

1 hour ago, Brett63 said:

Ok, all of my dash gauges have started constant sweeping except the fuel and air. With that, I have a check trans, check engine and ABS light and a flashing lost ECU comms. I have an Acoms system and can hook up to see what is going on, but ECU or nothing is detected.

My question is, who would this be a repair for? The engine starts and runs fine, so I doubt it's a Cummins repair, the trans shifts both forward and reverse, so doubt it is an Allison issue. Are we then defaulting to an RV service center? We are about 20 miles N of Tampa. I don't even know where to take it to try and figure out what is going on, but I know there is a loss of comms on the J1939 line between the Engine and the gauge cluster somewhere.

09 Monaco Signature

The first and most standard fix.  No AC power from the Shore of the Genny.

Remove the charging fuses from the solar so your solar panel is NOT connected.  Option is to just cover the panel with a thick blanket or a poly tarp.

Remove both negative cables from the House and the Chassis.  Frank says the positive is not necessary and may be the way that the stored energy is dissipated back to the battery.

Let it sit a while,  What you are doing is letting the systems, and there are a bunch of them reboot on the J-1939 data Buss that runs from the front to the rear.  There are a bunch of them.  Allison TCM & Shifter. Cummins’ ECM.  Bendix ABS & ATC…I think two. Your front gage and dash…the dash with the idiot lights is the input and then your gauges are attached to that module.  Your Aladdin or Silverlleaf monitoring system.  Think having 8 or so PC’s in a network, except they are commingled and constantly chitchatting with each other.  One has some issues, maybe 2….but you have to shut them all down and let them boot back up, simultaneously, and then, hopefully the one that is confused, will be OK.l.but as they come up and do the “handshake with the network, they also have to say good morning to each other PC and get a wave or a welcome back.

Reconnect the batteries,  Restart the engine.  If you still have an issue drive it and rest the braking and see if it shifts OK….maybe use the exhaust brake.  That means the engine and the tranny (shift and TCM) and brakes are working on.  That then narrows it down.  Post the results l

[Frank McElroy]

Brett is having an issue with his J1939 databus.  It could be a bad wire, a bad terminating resister or a bad module.

One item Brett didn't mention in his post was that there was a nearby lightning strike that did effect his coach (lost a 12v light string) but other more significant damage to other coaches.

What Brett is asking for is a recommendation for a nearby repair shop who is experienced and knowledgeable in working on a J1939 system.

In the meantime and for reference, the attached video is a very good one on how one goes about troubleshooting the J1939 databus.  Brett is doing the basic troubleshooting now. 

But if this doesn't work, he needs recommendations on where to take the coach for repair.

 

 

[Dr4Film]

To prevent collateral damage from any nearby lightning strike I have gotten into the habit of disconnecting the shore cord from the pedestal once I receive a warning on my phone of a severe storm warning. I run the generator which gives me the opportunity to exercise it for a spell. That isolates the coach electrically. It won't help if I take a direct hit though.

[Brett63]

53 minutes ago, Dr4Film said:

To prevent collateral damage from any nearby lightning strike I have gotten into the habit of disconnecting the shore cord from the pedestal once I receive a warning on my phone of a severe storm warning. I run the generator which gives me the opportunity to exercise it for a spell. That isolates the coach electrically. It won't help if I take a direct hit though.

I suspect you are not in FL this time of year or you would know that thunderstorms pop up without notice pretty much every day between 0000-2359. This particular strike was at 0245, and no notice. We would be on generator 24/7 during the monsoon season down here...lol

[Dr4Film]

16 hours ago, Brett63 said:

I suspect you are not in FL this time of year or you would know that thunderstorms pop up without notice pretty much every day between 0000-2359. This particular strike was at 0245, and no notice. We would be on generator 24/7 during the monsoon season down here...lol

You guessed it! We have never spent a summer in Florida and are currently in the White Mountain area of New Hampshire Workamping at Totem Pole Park. Much cooler weather up here. We only spend fall & winter at our Florida beach house but use the same protocol anywhere we are located.

There are hundreds of Weather Apps for your phone but not all of them will give you early storm & lightning warnings. I use the Fox 13 weather app and it has been very accurate and quick when alerting us to possible lightning in our area no matter where we are located.

Hopefully Frank has been able to help you resolve the issue with your communication data buss.

[Brett63]

On 7/17/2022 at 9:25 AM, Dr4Film said:

You guessed it! We have never spent a summer in Florida and are currently in the White Mountain area of New Hampshire Workamping at Totem Pole Park. Much cooler weather up here. We only spend fall & winter at our Florida beach house but use the same protocol anywhere we are located.

There are hundreds of Weather Apps for your phone but not all of them will give you early storm & lightning warnings. I use the Fox 13 weather app and it has been very accurate and quick when alerting us to possible lightning in our area no matter where we are located.

Hopefully Frank has been able to help you resolve the issue with your communication data buss.

We use the same app, and yes it is a very good app. We typically are not at our lot in FL this time of year, but medical forced us to be here this time. 

 

After several hours of trouble shooting and many texts and phone calls with Frank, a lot of sweat, and a few choice words The failed culprit is the ECM.

One thing for certain, I can say with pretty accurate sureness that I am very familiar with the J1939 data bus system on this coach, where every connector, module and resistor is, how to trouble shoot the system, what voltages and Ohms I should have, how it all interfaces together and anything else you want to know...lol I even think maybe Frank learned a little bit as well.

I couldn't ask for a better mentor than Frank McElroy, thank you Sir a million times. You have become a good friend through all of my coach issues which are proving to be well more than anyone deserves.....lol

[Frank McElroy]

Thanks for the kind words.  With a bit of guidance, your systematic troubleshooting with an ohm / volt meter and being able to find all the J1939 modules on the databus is what enabled you to identify the engine ECM as the bad module causing the loss of communication on the databus and the dash gauges to sweep continuously.  Hopefully the nearby lightning hit only damaged the engine ECM.  Fingers crossed.

[ncjimgr]

Frank,

Not sure if you have followed my saga about my 2006 Camelot getting hit by lightening. It took out mainly chassis items (along with an A/C board, tank monitors and Magnum remote display). It has been suggested the CAN Buss is in error. I had Cummins mobile service come here and they got the engine starting. It was the high pressure fuel pump as well as the engine ECM. He could not get to the ECM using the front or rear data ports. He finally plugged into the ECM directly and it was working. He re-plugged it into the data bus and it worked. Engine Solved. Maybe it rebooted.

Now the "check transmission" light came on with the engine start. The ABS light and ATC lights are on. The dash gauges go crazy, pegging and then going to 0. The transmission selector light segments will blink in conjunction with the gauges. We had Allison Mobile Service come out. He checked the transmission ECU and it was okay. He did unplug several modules with out changing the above scenario. He confirmed that we both smelled a burn smell in the front run bay. No visible burned wires or fuses. The transmission does work but, for safety, we had it towed to a service center and they said, we can not work on this, so it will be towed back to our RV Park. That is when I need to try my luck.

So...My issue is that no one near Crystal River, Florida will attempt to fix our coach. MANY RV Service Centers have been called all around Florida, by Progressive Insurance. I believe I need to start looking deeper into this myself. I was told there is a resister at the front of the CAN Buss and one at the end. I am thinking maybe the resister burned in the front run bay (if that is where it is), and that is what I smell. I do not know what it looks like, where either resister is and how to locate front or back units. My background is electronics so I have multiple volt/ohm meters. I just need direction! Can you give me any guidance? I am handicapped (bad legs) but I can direct friends to help me. Any help you can give me would be very appreciated...

JimG
2006 Camelot PAQ

[Brett63]

Jim, you are describing exactly my symptoms. After several hours of troubleshooting I am fairly certain my ECM is the bad module. The easiest way to check your terminating resisters is to disconnect all batteries thus removing all power. Then on either doetsch connector check ohms on pin C and D. The data test ports are lettered with A in the middle. When checking Ohmos on C/D pins you should see between 55-60 as each terminating resistor is a 120 ohm resister in parallel. on my coach there is a terminating resistor in the front run bay and within 10" of the rear doetsch connector in at the engine. They will be triangle shaped and have a coax type cable going to them with a green, yellow and ground wire. Hope that helps.

[ncjimgr]

Brett63,

Thank you so much for the response. The Cummins Tech checked the ECM and found it to be working properly, so I can eliminate that module. The engine now starts/runs but that is when we discovered the "Check Transmission" light + gauge issue. I believe someone sent me a layout of the CAN Buss to look at. The difficult part is finding the other modules. The Allison Tech checked all the modules connected to the transmission and he said they were all operating properly, just no communication between them, so I can eliminate those. My gut feeling is that the resisters are burned out.

Is the doetsch connector the data port located in the front run bay and in the rear? Not familiar with that connector name. Do you have a photo of what the terminating resister (triangle shape) actually looks like? I don't remember a unit like that in the run bay but, there again, I was not specifically looking for it either.

The coach is going to be towed back to my RV Park on Monday, so I will start the troubleshooting then.

Thanks again,

JimG
2006 Camelot PAQ

[Ivan K]

Jim, This video might also help you, it shows the resistors too.

 

[Brett63]

2 hours ago, ncjimgr said:

Brett63,

Thank you so much for the response. The Cummins Tech checked the ECM and found it to be working properly, so I can eliminate that module. The engine now starts/runs but that is when we discovered the "Check Transmission" light + gauge issue. I believe someone sent me a layout of the CAN Buss to look at. The difficult part is finding the other modules. The Allison Tech checked all the modules connected to the transmission and he said they were all operating properly, just no communication between them, so I can eliminate those. My gut feeling is that the resisters are burned out.

Is the doetsch connector the data port located in the front run bay and in the rear? Not familiar with that connector name. Do you have a photo of what the terminating resister (triangle shape) actually looks like? I don't remember a unit like that in the run bay but, there again, I was not specifically looking for it either.

The coach is going to be towed back to my RV Park on Monday, so I will start the troubleshooting then.

Thanks again,

JimG
2006 Camelot PAQ

Typically your bendix ABS module and the TCM modules are in the overhead of the first storage bay. The doetsch connector it the round OBD port located under the dash and in the engine bay.  I don't have a handy pic of the terminating resistor but they are grey and will have three (typically) orange dots on the end. It will be a plug that is the only one that is triangle shapped.  Attached is a generic picture of the resistor. Your shift pad on the dash is a module and I suspect you have a medallion on the dash which shows all of your idiot lights, that is a module for the dash cluster. That should have three plugs on the back of it, one is black, that has the J1939 data line in that plug for the dash cluster. If you have an alladin system that is a module, I don't think you have Vorad or that woul be a module. I believe that will be all of the modules ou have. In my case I can start, run and drive but my gauges all sweep constantly, ABS, Trans and engine lights are all on, my readouts are loss ecu comms, loss trans comms and I have no brake or turn lights. Through extensive trouble shooting I have found my ECM to be the bad non communicating module.

[ncjimgr]

Brett and Ivan...Thank you for the information. VERY Helpful! I will report back when I find something wrong!

JimG
2006 Monaco Camelot PAQ

[amphi_sc]

Interesting thread as the symptoms of cycling dash gauges similar to a problem I and several techs chased for 18 months before finding it.  Major difference is your engine runs implying the ecm is working whereas mine wouldn't.  Mine ended up being an intermittent relay that sometimes wouldn't close cleanly or would vibrate open just enough.  Have you tried thumping all the relays to see if it could be a bad wiper?  Something not getting powered up drawing the bus down?  On the other hand, you've had 16+ years of use and technology has advanced a lot so maybe it's just time to buy something new.  Summer sales are on.

[birdshill123]

I went through a com problem with our 08 Dynasty. Spent over $1500 at an FL dealer and git nowhere. I was at Massey in Phoenix and they gave me heck for dirty battery connectors. I was told they have to be shiny. My problem was intermittent. I returned to my shop in Mexico. All was good. But I was concerned the problem would return. Removed and cleaned a bunch of frame grounds. That was years ago and the problem never returned. Monaco tech  ( he was an electronics expert) said there have been problems with the Deutch  connectors. Often it is one that is bundled with a mess of wires on the RH frame close to the rear run box. I did find it and it looked OK. But I gave it a dose of contact cleaner. I have read that the pins in those connectors can be loose. Never take this problem to an RV dealer.  OTR trucks are easy to fix. They look fir a bad connector or wire. If thst does not work they install a new harness. In our unis the harnesses are custom. Another spot for a problem is in the drivers side console that has the shifter. I am told that Cummins that was across from the Old Monaco factory is familiar with that problem.

[Tom Cherry]

11 minutes ago, birdshill123 said:

I went through a com problem with our 08 Dynasty. Spent over $1500 at an FL dealer and git nowhere. I was at Massey in Phoenix and they gave me heck for dirty battery connectors. I was told they have to be shiny. My problem was intermittent. I returned to my shop in Mexico. All was good. But I was concerned the problem would return. Removed and cleaned a bunch of frame grounds. That was years ago and the problem never returned. Monaco tech  ( he was an electronics expert) said there have been problems with the Deutch  connectors. Often it is one that is bundled with a mess of wires on the RH frame close to the rear run box. I did find it and it looked OK. But I gave it a dose of contact cleaner. I have read that the pins in those connectors can be loose. Never take this problem to an RV dealer.  OTR trucks are easy to fix. They look fir a bad connector or wire. If thst does not work they install a new harness. In our unis the harnesses are custom. Another spot for a problem is in the drivers side console that has the shifter. I am told that Cummins that was across from the Old Monaco factory is familiar with that problem.

Good and timely and practical advice.  Along those same lines…..I had a gremlin pop up….not as bad.  I installed a fire protection system over my ISL.  Had to route the discharge hose from the cylinder to the sprinkler head I installed over the engine.  When I started to mount the tank, inside the engine compartment, there was a “wad” of wires where I needed to drill a hole….into the backwall of the rear bedroom.  I carefully tugged and moved the mess and then repositioned them and zip tied the bundle in place

THEN I started getting a false Dash alarm and an annoying (to DW…i can’t hear high pitched alarms) alarm.  The dash said….OPEN DOOR.  Say what.  There are NOT any limit or closure switches on my Camelot.  I KNOW that from inspection as well as the prints.  I went back and forth with the original guys in Oregon the Navistar kept on the phone 📞 .  They said….OPPS, you DO the “door alarm” harness.  It was the same one used on the Dynasty (or higher) and they THOUGHT that since the ISL 425 was used on the Camelots and as the lower end or standard on the Dynasty that I have a harness with an alarm wire that was NOT supposed to be terminated on the Medallion dash cluster…but was.  I called Medallion and got the prints and found the “pin” that fed this alarm.  SURE enough…connected.  I started to clip it….but I want back to the “rabbit hole” where it was probably passing through.  I repositioned the Bundle….and then banged and jostled and beat on it.  NO ALARM.  I then “reziptied” it in place.  Did this in 2010….no alarms in over 55K….

YES, I had a chaffed wire….and it was shorting out intermittently.  So. WIRING a issues are tricky…and an errant ground can wreak havoc…..

 

[ncjimgr]

Thanks for all the advice. Got a call from the insurance adjuster today and they contacted an RV Service center in Tavares, Florida I gave them. They are Coach Crafters, and they said they would look at the coach. They do some CAN Buss issues. It will be towed there tomorrow (although it can be driven but we are not sure how safe it would be). They are going to attempt to give the insurance company an estimate. Not sure what is going to happen, but, if they can not fix it, I have good advice from all you folks that answered me and I will attempt to correct it myself. I will let you all know what happens...

Thanks Again,

JimG
2006 Camelot PAQ

[Tom Cherry]

55 minutes ago, ncjimgr said:

Thanks for all the advice. Got a call from the insurance adjuster today and they contacted an RV Service center in Tavares, Florida I gave them. They are Coach Crafters, and they said they would look at the coach. They do some CAN Buss issues. It will be towed there tomorrow (although it can be driven but we are not sure how safe it would be). They are going to attempt to give the insurance company an estimate. Not sure what is going to happen, but, if they can not fix it, I have good advice from all you folks that answered me and I will attempt to correct it myself. I will let you all know what happens...

Thanks Again,

JimG
2006 Camelot PAQ

Jim, first, this comment should have been posted immediately on your original “Lightning Strike” as there so many folks that are following it and have spent a lot of time trying to help and assist you.  I did a lot of research, as did others and suggested 4 places….and here was your response….  Much of this offline and over the phone.

Thanks for the recommendations Tom. Most of those places you listed will not touch it! I do not think the repair shop in Tavares, FL called Coach Crafters was called. I will give the insurance guy that info. All others were called. We just need a repair estimate.

Bottom line, and i do understand your health issues and also not having an intimate knowledge, but your past posts were helpful and some progress was made.  In the future, when suggestions are made after a lot of effort and no action occurs…..group dynamics sets in and the amount of interest and participation drops off.

Please copy or post this in the original thread.  Good luck…. I felt certain that based on the research that Coach Crafters should be up to the task…..if not, then their webpage is overly hyped…but the reviews are good.

We all, those here and those not here, but following the original thread are trying to help as well as learn.  So keep us, preferably on the original topic, updated.

It seems that Mother Nature and/or those pesky electronic gremlins are rampart this year….maybe they have come out of COVID quarantine and are well rested….other than that….don’t have a clue….LOL

It is REALLY great that you now seem to have a solid lead and can get it resolved.  What is a bummer, though, since you are much closer to the “EPITOME” of all RV behemoths….LAZY DAYS….in the Villages as well as the original Tampa location ….that THEY don’t seem to have a clue or be interested.  THAT a is disheartening……sell ‘em….service ‘em….but we might NOT know how….sorry….

[ncjimgr]

Thanks Tom,

Re-posted my last comments to the original thread. Guess I thought this was the original...

Yes, we are not having much luck so far with this issue. We are fortunate we were negotiating with someone here in the park to buy their 2018 Forest River Cedar Creek Cottage (owner passed away over a year ago) and we did end up buying that unit and it is on our lot now so we have a place to live. I guess the Camelot was not happy with that scenario!!!

I will let everyone know what happens going forward after Coach Crafter's takes a look at it...

JimG
2006 Camelot PAQ

[Bradley]

Hi there, I know this thread is over a year old… but having identical problems with my gauges on my 06 Dynasty- my hours of troubleshooting is also pointing me to bad resistors. Still runs and drives normal. Did you ever get to the bottom of this? Thanks in advance!! 

[Frank McElroy]

Yes, the problem was that a lightning strike knocked out the engine ECM and the rear Kongsberg CCM module.  Both needed to be replaced.  This was a chassis multiplex coach with Medallion instrument gauges.  The terminating resistors were fine.