Another low air warning.

bigdog · 07-30-2011, 11:16 PM

I got an air warning lite, buzzer and the rear gauge went from full to 0 and back and stayed there while the buzzer and lite stayed on.Front stayed ok.I pulled off the road,did the air brake check and finally heard the air valve pop-off,but still had the buzzer and lite.I took off anyway and the brake didn't come on.Drove it home and the situation came and went. Called Freightliner and described the problem and he said that it was the VDC or VCD.Called the shop where I get my work done and he checked on the part and said it was a $500 part and that I should bring it in and they would check it out for sure as they would hate to replace the VDC (?) and find it was something else and less money..(I've spent a l;ot of money with them since I got this thing).
What is the VDC and why would it indicate a low air pressure when it isn't happening???? It seems to me that it would probably be a sensor or something of that sort.

Elkhartjim · 07-31-2011, 04:33 AM

I have a LBCU on mine-08 Freightliner chassis. Its the brains that monitor and light the idiot lights and gauges. My LBCU went out under warranty. I was having the low air pressure issue just like you.

Maybe this info from the FCOC group will help.

http://f1.grp.yahoofs.com/v1/oCc1Ttl...20FL%20VDU.doc

Norm4015 · 07-31-2011, 05:47 AM

My brother-in-law was having the same problem with the VDC. We removed it and I resoldered the connections on the circuit board. Some of the solder joints had very very small cracks and some looked like cold solder joints. After we did the repair he has had no more problems. I have talked with several people who say this is a common problem. If you are a handy man and good with a soldering iron you can fix it for free.

charles tuit · 07-31-2011, 07:04 AM

Do a search on VDC repair. Very comon problem and an easy repair.

Charlie Tuit
02 Journey, 158,000 miles
XL-7 toad

llmrealestat · 07-31-2011, 12:01 PM

We had the same problem and it turned out to be a loose wire under the dash. Fixed the wire, no more alarms.

Fred Cooper · 07-31-2011, 06:07 PM

Sounds like the VDC solder joint problem that primarily affected 1999 - 2001 chassis.

If you can't find the repair instructions, I have a word document that describes the repair of the VDC (VDU) using a soldering iron. I has a picture of where to look. If you need a copy, send me an email address.

Fred

J Walker · 08-01-2011, 11:53 AM

I had a VDC that gave improper pressure readings and had it replaced by Freightliner, Gaffney. The VDC provides the presure sensors and provides the digital signal to all of the dash instruments. Amazingly, the air lines for the front and rear air tanks connect to the VDC where the pressure reading is made. I would definitely try to re-solder the circuit board. I also have the procedure. Let me know if you want it. BTW Freightliner had problems with their VDCs for a year or so. We are unlucky to fall within that timeframe.

bigdog · 08-01-2011, 05:12 PM

Thanks for all the replies.I got it into the shop this AM,along with the directions for the solder repair and they got'er done in a couple of hours and we took it out and road-tested it pretty hard and everything's hunky-dory. It cost me two hours labor which I think is pretty good as I'm not good at that sort of thing.They pulled it,it's in the compartment with the inverter,took it apart,soldered it and it really needed it as three of the strips were cracked and put it back in for $150.
(smallest bill I think I've ever had on the MH)
So,again,thanks for the help.

Norm4015 · 08-01-2011, 05:28 PM

Glad you got it fixed. Once it is soldered correctly it will give no more problems. Happy travels.

free-to-roam · 10-20-2011, 04:42 PM

Latest...FL has ordered 9 parts to fix this, under warranty, as well as a recall issue, don't know what that is all about. Have as Nov 2 appointment in Tampa. Will post results.
I wrote FL requesting the location of the VDU, included my VIN, they responded via E mail asking me to go to a FL dealer for service. I went to Brooksville, Fl, to Register RV & FL, but the FL company wanted me to go to a truck dealer for the recall. Still have the screecher, about to get totally fed up with the string of service appointments, and shuffling. Will post after the 2nd, and let you all know...
Thanks! JR

Elkhartjim · 10-20-2011, 04:53 PM

Quote:

Originally Posted by free-to-roam

Latest...FL has ordered 9 parts to fix this, under warranty, as well as a recall issue, don't know what that is all about. Have as Nov 2 appointment in Tampa. Will post results.
I wrote FL requesting the location of the VDU, included my VIN, they responded via E mail asking me to go to a FL dealer for service. I went to Brooksville, Fl, to Register RV & FL, but the FL company wanted me to go to a truck dealer for the recall. Still have the screecher, about to get totally fed up with the string of service appointments, and shuffling. Will post after the 2nd, and let you all know...
Thanks! JR

I thought you had the VDC repaired a month or so ago. Is that what you mean when you say VDU?

free-to-roam · 10-21-2011, 07:30 AM

Have seen the Vehicle Data Computer referrd to as a Vehicle Data Unit also, seems like you can pick what term comes to mind first! Nutz isn't it!
Tried to get the thing fixed for a month, am having a terrible time getting a Freightliner to fix it, even though they say they know what the problem is. Register in Brooksville, Florida made the most headway, was ordering parts to fix it, under warranty, when they ran the VIN, Freightliner responded by dtopping their participating in the repair, instead sending me on down the road to another shop, this time in Tampa, scheduled 11/2....will let all know...
What a frustration!
J.R.

free-to-roam · 11-03-2011, 04:01 PM

All fixed....under warranty. What a voyage to get it fixed!
Thanks to all....

Dutcstar3891 · 12-28-2011, 03:05 PM

Quote:

Originally Posted by J Walker

I had a VDC that gave improper pressure readings and had it replaced by Freightliner, Gaffney. The VDC provides the presure sensors and provides the digital signal to all of the dash instruments. Amazingly, the air lines for the front and rear air tanks connect to the VDC where the pressure reading is made. I would definitely try to re-solder the circuit board. I also have the procedure. Let me know if you want it. BTW Freightliner had problems with their VDCs for a year or so. We are unlucky to fall within that timeframe.

I am having the same issue with my rear brakes in a 2001 Dutchstar. Which joints on the ckt board do I resolder?
Thanks for any help you can provide.