Won't start- PATS shutdown?

[Dekeman]

Hello,

My '00 WS will not start. It recently had an alternator replacement, and my wife said it stalled on her in the church parking lot on Sunday. It's run fine since then, and I suspect a weak battery. When checking the battery today, I had her start it, and the start immediately stopped. What I mean is that it wouldn't even crank or turn over once. It's like something is stopping it from starting, and I suspect that the PATS system is malfunctioning. The keys are original to the vehicle and I have relocked and unlocked it fully with both keyfobs, and used both original keys to attempt to start it. It does the same thing in all cases. Ideas or suggestions are appreciated. Hope my description is sufficient; I've never seen or heard a vehicle do this.

[Windstartled]

Originally Posted by Dekeman

It's like something is stopping it from starting, and I suspect that the PATS system is malfunctioning. The keys are original to the vehicle and I have relocked and unlocked it fully with both keyfobs, and used both original keys to attempt to start it. It does the same thing in all cases. Ideas or suggestions are appreciated. Hope my description is sufficient; I've never seen or heard a vehicle do this.

I have the misfortune -or the luck depending on how one sees it- of being familiar with PATS issues with my own '00 Winnie. First of all determining if PATS is involved is quite easy: the "Theft" light on the instrument cluster will begin to flash rapidly when the ignition is turned to ON. Not the normal flash it always does when the ignition is off but much faster, you can't miss it. When it does this the PCM won't allow the starter to function, turning the ignition to START you will just hear a faint click then nothing, it will be just as if the ignition was turned off. On some other Ford models PATS will allow the starter to work but will cut off fuel delivery so it won't run either but on the Windstar PATS cuts all electric power to the engine. It's deadly efficient against theft but supremely annoying when it's your own van you are trying to start and it won't let you.

The way PATS work is relatively simple. When you turn the key to start the engine a PATS transceiver located on a ring around the ignition cylinder reads a code from the key chip and forwards this code to the PCM, which then compares the code to the one stored in its memory and allows the engine to start if the codes match. There are basically three PATS issues that will prevent starting the engine: A) using a key with the wrong code either because it's the wrong key (duh!) or because the key chip has become corrupt and is unreadable B) the transceiver module is malfunctioning C) there is a problem with the circuitry between the transceiver and the PCM.

You can eliminate or confirm possibility A by using your spare coded key (assuming you still have it) and try to start the engine with it. If neither key works chances are it's not a chip issue and that's usually a good thing because a bad chip requires that you have your vehicle towed to a dealership to have a new set of keys cut and programmed for it. I suppose it's possible you just bring the PCM to the dealership but I'm not 100% sure, in either case it will be an expensive ordeal.

Possibility B (bad transceiver) is the most common cause of PATS issues and fortunately, the easiest and cheapest to fix. First check the fuses related to PATS, IRC they are #9, 10, 16 and 28. Those rarely fail but you never know so check them just to be in the clear. If fuses are ok then the transceiver needs to be replaced. The transceiver is just that, it reads a code through an integrated antenna and relays it to the PCM via wiring. The transceiver itself is not coded and requires no programming so ANY functioning transceiver from a 99 and 00 Windstar will work on yours. Ford sells them at a hefty price and usually insist on installing it themselves which is pricey. You can do this yourself using precisely three tools: an 8mm socket, a small metric hex key and a phillips screwdriver. Job takes less than 20 mins. As for the replacement transceiver you can get one off eBay for 5$ or a self-serve junkyard where they will often just let you have it for free. Personally I leeched three transceivers from a junkyard just to make sure at least one would work and the first one I tried worked like magic. Total investment for this fix: about $10

Possibility C usually involves damaged or shorted wiring between the PATS transceiver and the PCM. Visual inspection is tedious but not very complex. Replacement of the wires will usually fix this issue. This is more common with vehicles that have a remote starter (like mine) because the starter module is secured using only cable ties and can shake wiring loose with time.