Sporadic rear air bag pressure alarm

[Dave_H]

Recently bought a 2004 Newmar Kountry Star with Cummings 330 engine and Spartan chassis. Took it on our first trip this past weekend and noticed on at least 3 different occasions while driving down the road that the alarm sounded briefly, rear air pressure gauge and fuel gauge would both goes to zero and fuel gauge to empty and then would immediately return to normal. One one occasion the front air pressure gauge did the same thing and the low fuel light came on and within a couple of seconds again returned to normal. Did not notice any deflation in air bags when this occurred. Also one time the leveling jacks down alarm and light came on while driving but all jacks were in retracted or up position. Held down the jack up button for a few seconds and the alarm stopped. Is this common or a indication of a possible malfunction?

[Skip426]

Welcome to iRV2.

Sorry you're here with problems .

This sounds more like an electrical problem than anything to do with the air system .
The air system on your chassis has separate tanks for the rear and front brakes , the air suspension, is fed from one tank and is isolated by brake protection valves, so that a blown air bag will not leave you with no brakes.
With the jacks down system also giving alarms , the only common thing with the air alarm is electrical , possibly grounds in the dash board .
Contact Spartan , with your chassis serial number , and get an air system diagram and chassis wiring diagrams . Mention your problem with alarms they may be aware of the issue and have a fix.

[OldHatt45]

Dave,
I had a problem VERY similar to what you are experiencing..
It turned out that there was a Pink Wire that is the signal wire to the gauge cluster that someone had pierced (to test possibly) and had corroded and finally opened completely. The break was in the area over the rear axle.
It was labeled SP209 and is the Pink Wire of a Twisted 18 gauge pair, (SP210 was the Gray wire in that pair). It runs from the Instrument Cluster to the 3 ECU's in the back, near the engine.


Call Spartan and get the Wiring Diagrams for your coach. Tell them your symptoms and chances are they might even mark up the wiring diagram for you.


Hope this helps


Drew
2003 Travel Supreme 40DS02

[rvbiker45]

Originally Posted by OldHatt45

Dave,
I had a problem VERY similar to what you are experiencing..
It turned out that there was a Pink Wire that is the signal wire to the gauge cluster that someone had pierced (to test possibly) and had corroded and finally opened completely. The break was in the area over the rear axle.
It was labeled SP209 and is the Pink Wire of a Twisted 18 gauge pair, (SP210 was the Gray wire in that pair). It runs from the Instrument Cluster to the 3 ECU's in the back, near the engine.


Call Spartan and get the Wiring Diagrams for your coach. Tell them your symptoms and chances are they might even mark up the wiring diagram for you.


Hope this helps


Drew
2003 Travel Supreme 40DS02

Drew,
I have been having the same issue for several years. Spartan has been contacted and they have given several avenues to pursue that have not been successful. I have the wiring diagram for the MH and that has been informative, but no solution has been found.
My question is, where are the 3 ECU's in the engine compartment? Where are the #209/210 wires routed, left side/right side over the axle? Are those wires in protective conduit along with other wires, I assume there are many in each bundle.
Thanks for your help.

[OldHatt45]

Don,
Yeah, I had the sporadic thing for a year or 2 myself so I know what you mean.
To answer your questions.
1. On my rig, the ECU's for the transmission and ABS are in the same compartment as the Power Cord. If I remember right, the engine ECU is there as well. Engine and Tranny ECU's are on the back wall of that compartment.
2. Yes the main wire bundles on my rig are run down the Drivers side and along the frame rail. Once they get a little forward of the rear axle, they go into the frame rail and exit up in the generator compartment.
3. Yes they are in a conduit, but in the area over the axle, they break out of the conduit and are in a taped bundle.
Now the questions you didn't ask.
4. The wiring is broken into front harness, backbone harness, rear harness, engine harness. There are connectors at the generator compartment, over the axle and back in the engine compartment. The connectors at the rear are over the axle on the drivers side.
5. If you look at the Wiring Diagram Labeled Instruments, and then look for the "Message Center" (lower left on my diagram) you'll see the SP209 & SP210 Pink & Gray 18 gauge twisted pair. This was just to show you the wires.
Now find the Datalink/Diagnostics Diagram. you'll see those same 2 wires on the left side going into the diagnostics connector as the J1587 Positive and Negative (under the dashboard). Following these wires to the rear they eventually come to a connector in the rear labeled "70" (on my rig). From that connector (which is over the axle) these 2 wires show a connection going to the 3 ECU's and to the diagnostic connector in the engine compartment.


In my trouble shooting, I disconnected the "Message Center" connector under the dash (I actually pulled the dashboard panel) and jumpered the pink and gray wires.
Then went to the rear and tested for continuity. There was no continuity at the engine diagnostic connector.
Then started tracing toward the front. After testing what I could, I figured out that the break was somewhere between the 70 connector and the ECU's.
Fortunately for me, the local place I use for other engine/chassis work took over from there and found the broken wire pretty much in the area I thought it would be. The guys at my place are really good about listening to what I tell them and found the break in a couple of hours. I gave them printed out copies of the diagram and marked up the diagrams to help them.
They fixed the break and (VERY IMPORTANTLY) they sealed the fix properly so it wouldn't corrode again.


Hope this helps
Drew
Travel Supreme 40DS02

[rvbiker45]

Drew,

Many thanks for the well written reply on the gauge problem. I plan to work on it this weekend. I got the schematics out and found the wires, 209/210 that you referenced. That will give me a good lead in chasing this intermittent problem down.
I will keep you posted on what I find.

Thanks again.
Don

[rvbiker45]

Drew,
Well, I spent most of Saturday chasing the twisted wires from the instrument panel to the ECU panels. I did find an unrelated wire that was in need of some re-insulation as the original was torn away. Fixed that.
I could not find any interruptions in integrity of either wire. So I improvised a bit. I ran an parallel set of wires from the instrument panel to the ECU plug that was home to the 209/210 wires. I tapped into the original wires to give a clean path for the signal to the instrument cluster. Will this work? Road testing is the only way that I know for sure to give it a try and see if the problem reappears. Especially since I could not locate a problem with the wiring.
We plan to leave Tuesday for about a 800-900mile trip. Even then, there have been times that we did not get the alarm and warning lights even after an even longer trip. I will keep you posted on what sort of experience we have. We are hoping for the best and a permanent fix.
Thanks again for your help.

Don

[OldHatt45]

Don,
Theoretically it should work. LOL
On my rig, it was a pinhole in the insulation that allowed the wire to corrode.
Also in my case, I experienced the same thing. Hours and hours on the road and no problem. Then all of a sudden, the problem would appear and sometimes go away after a time.
Running a parallel pair is a good thought. If you tapped in at the connector, it should be good. I would assume that you made sure the new wire was well insulated and protected. You have nothing to lose. I would give it a check ride over some not so good roads. Wishing you good luck and I hope you got it squared away.


Drew

[Dave_H]

Don,

I would also be curious as to what you find out after a couple of long test drives. I currently have my rig in the Cummings service shop for a few other items to be looked at. I explained the issue I was having with the periodic alarm and air bag and fuel gauges momentarily dropping and then returning to normal. Of course like many things it won't happen while at shop. They said they took a look at it but could not find anything unusual. I printed out the comment from Drew how he corrected his issue hoping that might give them an idea where to start. Not getting my hopes up however. Another issue I had the morning I was going to drive to the shop was I could not get my jacks down alarm to go off and as a result air bags would not inflate. Noticed a leak in front driver side jack but the front passenger side was the one that still had about a 1 1/2" left to go before being fully up. Put a small car jack under the coach jack and immediately air bags began to inflate. Shop said they replaced a T in the line where it was leaking and thinks that should fix the problem. I am suspicious that this small leak would prevent full retraction of the jack. Hydraulics are not reversed on retraction but don't they totally rely on spring tension and zero hydraulic pressure to retract?? Also like so many others with similar year and coaches was told ball joint boots are totally shot and should be replaced. $$$$ Said there was very little play in the ball joints but a matter of time before they get worse. We don't put many miles on per year and rig is stored in doors. Should this be a concern for me now or like I have read from other that keeping them clean and perhaps trying to wrap with a flexible rubber wrap to help minimize dirt and water getting in there may buy me more time.
Thank you all for your update posts and I will post if the shop by luck finds anything pertaining to my situation.

Dave

[rvbiker45]

Drew and Dave,

I did tap into the original wires at the speedometer and at the ECU just before the multi-pin connector. The entire length is covered in the black slit tubing and taped and tie-wrapped in place. Each connection is covered in liquid tape as an extra seal. I will give it a good workout this week and give a report of what is happening with it. Hopefully nothing.

Dave,

A couple of things come to mind concerning the jack not coming up. If the solenoid is releasing pressure, the springs should bring the jack to the fully retracted position. You can manually release the solenoid, usually mounted on the hydraulic reservoir for the jacks. Also, check the style of springs that you have. If they are the same diameter the whole length, they are the old style. The new style, and stronger, have a taper at each end going into the hook. They are easy to replace if you are handy.
The air leak, may have been an issue, but I doubt that it was related to the no retraction problem. I think those are two separate issues. The air leak may have been in the ride height leveling valves. Mine have failed all the way around at different times. Besides, the air and hydraulics are not mixed, so the explanation is suspect.
I have to tell off on myself here. I was working on the MH for several days and I could not get it to air up on the bags as I thought it should. It turns out that there is a shuttle valve that goes between dump and stow. In a HWH manual, I found the proper way to address the issue so it does not happen again. Always press the stow button on the levelers on start-up to move that shuttle valve to the inflate position away from the dump position. I do it every time now.
Moving right along.

The ball joints. While they are still in good shape, look around for a good shop that can do the work. Not all big truck shops will touch a Spartan chassis. It requires special tools and i suppose some would rather not bother with it. I had mine replaced this January. It drives very well now and the old ones were shot at 85,000miles. I can't address if wrapping the ball joints will make a difference, but keeping it lubed probably will help a lot.
Spartan will replace them at the factory if you happen to be going that way.

Good luck and keep us posted and I will do the same.

Don

[Dave_H]

Don,

Thanks for the info. I should have been a bit more specific regarding the leak on front driver side jack. It was leaking hydraulic oil apparently at a T in the line. Once the jack on passenger side was totally retracted with a little assistance air bags inflated to normal. I do have the older springs as they are the same size all the way, will look at replacing with the newer ones if problem persists. The coach only has 41,000 miles on it and if ball joints are showing no or very little play, I am hoping to get some more mileage out of them before needing to replace by hopefully keeping them clean as possible and greased.

Dave

[rvbiker45]

Originally Posted by Dave_H

Don,

Thanks for the info. I should have been a bit more specific regarding the leak on front driver side jack. It was leaking hydraulic oil apparently at a T in the line. Once the jack on passenger side was totally retracted with a little assistance air bags inflated to normal. I do have the older springs as they are the same size all the way, will look at replacing with the newer ones if problem persists. The coach only has 41,000 miles on it and if ball joints are showing no or very little play, I am hoping to get some more mileage out of them before needing to replace by hopefully keeping them clean as possible and greased.

Dave

I know the T on the hydraulic jack that you are referencing. I have had the same problem in the past. If you have not been doing it, I would suggest using some lubricant like WD-40 on the jack cylinders. Spray and wipe them down. I don't do it every time, but they do seem to work better when cleaned and lubed.
The ball joints are probably going to last you a long time, but when they start to wear, they seem to go bad in a hurry. If you have a good alignment and it starts to take a bit of effort to keep it tracking correctly, maybe it is time to give them a serious look.

Don

[rvbiker45]

We got back from our trip this week with about 800 miles on the clock. The original problem with the air and fuel gauges dropping to zero and then back to normal happened again, several times on this trip. So, I have not isolated the problem.

I spoke with Spartan today, at length, about the problem again. The person that I spoke with in Parts said they had received a request from a customer for a new "message center" because of the same issue that several of us have had. They have not had any feedback as to if that fixed the problems. I was under the impression from our discussion that the part that was ordered was the speedometer. It was not. It is the 16-lite module that has all of the icons when the ignition is first turned on. It is called a "Tell-Tale" module. It sales for about $195 from Spartan. The round speedometer with the speed and the mileage/hours of operation in the small window is the 5" SCU unit. That unit is $500+. They could not tell me how the signal information gets from the ECU to the 4-in-1 gauge with the air-fuel-and volts. I have a call in now to the technical folks at the company where the gauges are built. I hope to find something out as to what the "Tell-Tale" and the SCU units do and what part they play in the whole system other than just a display.

I wish I had better information to pass along concerning the erroneous gauges.
Maybe I'll hear something tomorrow, Thursday, 5/24/2018.

[Dave_H]

Don,

Really appreciated the update and please let us know what you hopefully find out tomorrow.