Hey guys,
Our 2003 expedition intermittently dies while driving or sometimes doesn't start. When the car is in motion and this happens, there is no warning, no chugging, sputtering, etc--the engine just cuts out. There is still power to auxiliary, but the engine just quits. We coast to a stop, having lost power steering and brakes, but the rest of the electrical seams to work.

When we try to turn it over to restart it, we get nothing. No click, no chug, no usual truck-in-need-of-repair sounds--it's as if the truck is immobilized. And sure enough, when we turn the key to the on position, the LED on the dash which usually glows a solid red for about 3 seconds on start up does not glow at all. The LED stops blinking when we turn the key and the truck wont start. In this state, the truck does not give us the odometer reading, instead displaying a series of dashes: "------".

There's nothing we can do but wait for the car to get over it. When it does, it starts up as usual, as if it didn't have any problems with it at all. The usual wait is about 45 minutes, but sometimes it has been a few hours. We've towed it to the dealer a few times while it hasn't been working, but by the time it arrives and they go to check it, the car is working again, and we are out a $100 diagnostic indicating the car is running fine. The dealer suggests that they could do some exploratory work to see if they can find the problem with no guarantees as to time it will take to find/fix problem. We could be out $100s with no solution.

Please help!

We've noticed recently that if we unplug the set of 3 quick connect cables that run into the passenger compartment on the passenger side (see picture), that we can get the car to start by leaving these unplugged for about 3 minutes. In particular, we've noticed that the set of plugs closest to the wheel well controls the LED on the dash. If we have the plug unplugged and we put the key in the ignition, turn it to the on position and then plug the plug in, if the car is working again, the LED will begin to glow.

I've got some vide for you starting the car when it is working and when it is not working. I've also got a picture of the set of plugs referred to above.

both videos and pic: http://gallery.me.com/frankkarabotsos#100213

or youtube:

dead truck: http://www.youtube.com/watch?v=F8-5NFxfH5c

alive truck: http://www.youtube.com/watch?v=CXKfg5e-ek8

and flickr for the pic: http://farm4.static.flickr.com/3457/...bddf30.jpg?v=0

So, what do you think?

Thanks,

Frank

 

Is it possible that the key is damaged? Have you tried a different one? What I'm not sure of is if the PATS system is always active, or just when first starting the car. If it's only when starting, then my suggestion won't have any measure.

 

PATS is supposed to turn off when you start the car. This is indicated by the long flash.

Would a short in the electrical system disengage the PATS when the car is on?

 

what was the solution to this? This is exactly the problem I am having.

 

The computer was fried. Replaced it and the problem went away.

 

Rats. Not the answer I wanted. If you don't mind me asking... about how much did that set you back?

 

They found a used one for us. About $1000 Canadian if I recall correctly, all in. Not before they tried reprogramming it $300 and replacing our intrument panel $600. At least you won't have to go through the hassle I did.

 

Is the computer specific to the PATS system? There is another current thread here regarding aftermarket alarms and a $15 bypass for the PATS system.

 

No, it was the main computer.