Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 09-22-2013, 11:23 AM   #1
Junior Member
 
Mid Atlantic Campers
Freightliner Owners Club
Join Date: Sep 2013
Location: Chesapeake
Posts: 3
Air Pressure erratic changes

I have been experiencing a problem with the air pressure monitoring system on my 2008 Sportscoach Pathfinder. The coach is built on a Freightliner XC Chassis and I have been reading a bunch of stuff about the VDC/VDU and the MMDC, however, I can't seem to find this "module" anywhere on the coach. I have traced airlines to every place I can think of on this thing and cannot find the module. Not sure it even has one - the green/red hoses that are suppose to be attached to this module run directly from the brake pedal module (just under the floorboard) to the to the gauges in the dash - I disconnected to hoses to see if there was a problem with moisture, but nothing but dry air came out of them. I have recently changed the dehydrator filter cartridge thinking that was the problem, but the problem still exists. The gauges will just suddenly drop to zero and the alarm will sound - still have plenty of air pressure but the behavior is erratic - sometimes the front gauge will drop and alarm, sometimes the back gauge will drop and alarm, some times they both go together. I believe this is an electrical problem with the computer that monitors the system, but cannot find any clear guidance online to resolve the problem. Any help from anyone out there would be greatly appreciated. Thanks. Jeff
2008 Sportscoach Pathfinder 384TS - 2007 Chevy Tahoe.
__________________

__________________
Steelersfan1 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 09-22-2013, 11:36 AM   #2
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 14,972
Freightliners free help line 1-800-385-4357 ,have your serial number handy, may be able to help with approx. location. While your on the phone inquire about joining "Access Freightliner " for online access to parts and wiring info on your chassis.
The air lines attached to the VDC on my coach are 1/4" the smallest lines on the whole coach. I think I have a picture, if I can find it , I'll re-size it and re-post.
__________________

__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 09-22-2013, 11:50 AM   #3
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 14,972
Here is a picture, showing VDC, on the left , Trans controller , center, and VIM-V.
Air lines are visible lower left corner. Because F/L supplies a bunch of extra hose and wire in the harnesses the coach maker can relocate these modules. Mine are in the engine bay , passenger side, with the extra hose & wiring , they could be moved 4 > 5 feet from there.
Edit: Just realized there is nothing for scale in the photo. VDC is 8" square 1 1/2 " thick.
Attached Thumbnails
Click image for larger version

Name:	IMG_0242 (640x360).jpg
Views:	239
Size:	157.0 KB
ID:	46547  
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 09-23-2013, 11:35 AM   #4
Junior Member
 
Mid Atlantic Campers
Freightliner Owners Club
Join Date: Sep 2013
Location: Chesapeake
Posts: 3
So I just got off the phone with Freightliner and they explained to me that the problem is actually with the jumper wires that connect all the gages together from the LBCU (Light Bar Control Unit) which was introduced into the XC-S Chassis in 2007 (hence the reason I have one of the first available). Apparently Coachman didn't do a very good job securing these wires under the dash and over the years they have vibrated loose (at the plugs) causing the erratic behavior of the air pressure gauges and alarm. They have since developed a more robust harness/jumper wires which they are shipping to me this week. In the mean time, I will be disconnecting each section of the harness to clean each connection with an electronics cleaner and then reconnecting with some dielectric grease. This should work until the new harness arrives.

The representative at Freightliner told that this would definitely fix my problem - sure hope he was right - more to follow...

Jeff
2008 Sportscoach Pathfinder 384TS/2007 Chevy Tahoe/Blue OX
__________________
Steelersfan1 is offline   Reply With Quote
Old 09-23-2013, 11:43 AM   #5
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 14,972
Good that your not the only one to ever have this problem and that there is a fix. Hopefully the replacement parts are the cure.
Were you able to get info on MMDC location or do you even have one ?
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 09-23-2013, 11:51 AM   #6
Senior Member
 
Skip426's Avatar


 
Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 14,972
Jeff, It looks like your typing your coach info at the end of every post,
If you open the " User CP " on the blue bar left end, under the welcome message. Then go to " Edit Signature " on the left side of the User CP page and enter you info there. It will automatically appear below your posts , as mine does below.
__________________
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 09-24-2013, 05:46 AM   #7
Junior Member
 
Mid Atlantic Campers
Freightliner Owners Club
Join Date: Sep 2013
Location: Chesapeake
Posts: 3
Skip, thanks for the encouragement. Last night I disconnected each of the jumper wires starting from the LBCU - they are daisy chained from the LBCU to each of the gauges in the dash including the speedo and tachometer - sprayed each connector with electronics cleaner and then applied a small amount of dielectric grease and reconnected. I also secured the last jumper that left the temperature gauge and lead to the air pressure gauges - the jumper was about 24" too long and Coachman did not secure the wire at all under the dash. I coiled up the jumper and zip tied it to a secure location under the dash - Although I didn't have a chance to do an actual road test last night, I'm pretty confident that this temporary fix will hold me over until the new, more robust, harness arrives. I would also guess that this fix would most likely solve the problem permanently if the owner is willing to check the connectors periodically - it only took me about 45 minutes to pull the dash pieces off, clean and apply the grease. Although this may vary from coach to coach, it is a pretty simple and easy way to eliminate the problem. I do not believe that Freightliner continued to use the MMDC from 2007 on - the new LBCU is now the "brains" of all the indications. I traced the air lines from one end of the coach to the other and did not find any type of device that resembled the VDC/VDU or the MMDC. I did not ask the technician on the phone yesterday - I may call back today just to inquire about it. Thanks for you help and please feel free to share this with anyone else you might know who is experiencing similar problems. I will post the part numbers of the jumpers when I received them so they may be ordered by folks who are out of warranty (5 years).
__________________

__________________
2013 Newmar Mountain Aire 4344
2007 Chevy Tahoe w/Blue OX towbar
Steelersfan1 is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:39 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.