Ok,
First I had to argue with the parts guy at the local ford dealer that such a thing exists as a VSM on a 2003 navigator, after insisting there is one and making him look **** up, he came up with a part number of 4L1Z-15604-AD with a description of a security kit, is this the VSM? Also, anyone have experience pulling it out on a 2003? Most of the vsm references I can find in the search are for the trucks where its mounted in a different spot. I can get to the 3 connectors that go to it, but the box its self is a bit out of reach (If i'm actually looking at the right thing). Can someone confirm that hte VSM is in fact mounted on the passenger side, above the fuse box way near the top of the dash on the inside of the dash?

 

That depends on what you think VSM stands for!
Abbreviations are okay, but it's good practice to use the long version once at the beginning of a message so that everyone knows they're all talking about the same thing.

For example, to you is it a Voltage Sensing Module, a Vehicle Speed Modulator, a Vehicle Service Message indicator, or a Variable Speed Module?
See what I mean!

 

Thank you alloro, that would insure that everyone is on the same page.

 

Well, I took apart the dash and pulled the VSM Part # on it says

2L1T-15K602-AM
RECV ASY-ALRM&LK SYS R/CONT

guess i'll go down to the ford dealer on monday and hand it to them and say, This **** is broke, and obviously it exists in my car cause here it is.

Pretty sure I got the right part in my hand, I opened it up and its a circuit card with some surface mount components and a 10 inch or so long bare wire thats soldered to the board at one end and just runs along the inside of the case (Im assuming an antenna).

Too bad I dont have access to my microminiature repair lab that I had at my last duty station, would just throw it on there and find the bad component and replace it.

First image is the inside
http://picasaweb.google.com/lh/photo...eat=directlink
2nd one is the label
http://picasaweb.google.com/lh/photo...eat=directlink

 

Sorry, Vehicle Security Module
aka Body security Module
Shop manual just calls it VSM in the diagram

 

Hi! I know you opened this thread a while ago but I'm currently have exactly same issues with my 2003 nav. Have you figured out and fixed your truck? Was it VSM at all?
I experience exact same problems as you described. Power locks don't work, radio stays on, windows work after door is open, lift gate don't work and automatic lights don't work. In addition to that I think 4wd stop working and air suspension quit.
When you replaced VSM had you had to programm it? How your entire truck repair ended up?

 

Any update whether you fix the issue or not? We would like to know and if this part is interchangeable with another vehicle of the same year. Would you please let me know.

 

Also would like to know if it fixed it. My 04 is doing something, in the setup menu it says data error for the liftgate, lights, steps and locks. After disconnecting battery now they are not even listed.

 

Mine was the T-Mobile Syncup Drive that was causing the issue once I removed that everything went back to normal!