PATS Received Invalid Format of Key Code From Ignition Key Transponder
B1681 FORD - PATS Transceiver Module Signal Is Not Received

Is the key transponder intermittent or pats transceiver bad . I don't

know how key transponder is powered . I don't know about the wire connections to pats lays out , does the pats send radio signal to pcm with code or does it use can bus .


I copied this from a post so I don't know if its for our vehicle , but it has positive power and a ground so maybe see if thats getting flaky . Plus it has a tx wire and rx wire that is shielded tx -transmit ,rx recieve.
I found a better diagram in my repair manual .

Maybe you can monitor power going into pats . The ground area by passenger kick is a known corrosion problem . It appears to send codes over hard wires. Maybe I can learn something here but I know this is a tough area .Hopefully you can find a weak connection and post some pictures .

 

G200 ground maybe on drivers side it says left A pillar so its from a driver perspective. Left would be drivers side . I really don't know the a pillar from b pillar .

 

Given those TWO codes, looks like the PATS has received an invalid Key-Code FORMAT from the key transponder, and the PCM has not received a signal from the PATS transceiver.

Check the easy stuffs first:

Any other keys on the key ring?
Especially any other transponder keys?

Does this vehicle have an aftermarket remote start?

And as Red suggested, check fuse 28 in the CJB to be sure is has clean and good contacts, as well as the ground path. If the ground was bad in the driver’s side foot well you would have other problems, but it wouldn’t hurt to see if the black wire coming out of the PATS transceiver module has a good ground.

 

You can replace pats module but you have to have a really good scan tool to copy your existing . It still takes some knowledge to initiate it ,there are you tube videos but its usually a guy who does a lot of this for shops . Plus we don't know about the transponder by the key slot or inference from something in your vehicle .
Me I would try a different key , then I would see about changing transponder . I would also be looking at whether i had any magnets or electronic devices near there to screw it up .
How is transponder powered ?

 

The transponder grabs just enough energy from the transceiver over the air signal to send back its Key Code.
(That’s why the transponder doesn’t need its own battery.)

 

thank you and everyone else who has helped out, I’m having someone check out the PATS system this week. I’ll report back when it’s hopefully fixed. Thanks again!

 

I think you are wise to get help on a complicated problem like this . It gonna take a good tech to resolve this and some good equipment .

 

So far I can't locate a diagram for the transponder around the key slot . Its some times described as the halo . It gets its power from somewhere and may act as the antenna to receive the code from the key and it sends it to the pats module which compares it with the pcm stored code . Its not a perfect system as crooks can steal the code from your nearby pocket key and clone it among other ways , these readers can be bought from china .
If you have the diagram for 04 to 08 I would like to share it with others to help determine where to test connections .
As for the poster here Remove all other keys from around your vehicle ,nothing else on your key ring . If that doesn't work, get your key cloned as the one you have may have an intermittent circuit in it . That would be before changing transponder around key slot .

 

Just so we are all on the same page, the ”transponder” is the RFID chip that is in the key.

And the “transceiver” is another way of referring to the PATS module (I.e., P-assive A-ntitheft T-tranceiver S-ystem) module.

The halo is the ring around the key slot and is typically part of the transceiver. The transceiver sends a small current through this ring. The energy from this ring is enough to power up the RFID chip in the transponder with just enough energy for the chip to send back the key’s code. (That’s why the transponder can function without its own battery.)

Here is a brief explanation of how the earlier PATS functions, much better than I can describe.

https://ricksfreeautorepairadvice.co...itheft-system/

Here’s hoping the OP reports back with a success and an explanation.

 

I kinda realize how its supposed to work but I can't find any wiring on the halo . There is a real problem with naming here some call the halo the transponder ,some call the key chip the transponder . But the power schematic on the halo wires escapes me , I must be looking at the wrong place . Maybe the pcm is exciting it but I can't find it . The key on or crank signal should bring the halo on but it makes sense that the pcm controls this . I know the pcm has the code and the pats sends it to pcm to see if it fits. How do we know if the halo wires are intact. It has to power the key chip and pickup its code ..
my 05 is not blue booked for much as far as insurance goes , I'm not sure I want pats at one point if it costs so much to repair . So yes I would buy a pcm with pats disabled ,enough overkill .

 

The PATS that I have seen has the halo as a hard part of the transceiver, so no wires between the halo and the transceiver to back probe.
The web address I posted above shows a picture of a transceiver with the attached halo on the first page.

This web address:

https://diag.net/msg/m3veh2km3nqn15n1xgsfwedt0l

shows scoping the transmit and receive lines between the transceiver and the PCM. It also indicates why you may not need to program anything if you change out the transceiver.

 

Well, I wanted to close the book on this thread for the benefit of others who may come along in the future. Sorry for taking so long to do so.

The way it was left — was, with great help from forum members, I had exhausted all options available to me, and I arranged for the truck to be towed to a reputable local garage. That was back in the beginning of June. I brought the mechanic up to speed on everything I had done prior to try and figure this out, and that I thought it was most definitely a PATS issue. One of the things he tried that I hadn't, was fitting a new transceiver. It was a no-go on that. Next reports back from the mechanic was he suspected it to be a failed PCM, and he gave me price options on a PCM replacement. I went ahead and told him to order the new PCM, which would come with two blank keys I could cut for my existing ignition tumbler. I didn't hear from him for the next three weeks, until I received a call that he was "cutting his losses" and wanted me to tow the truck away. He said the new replacement PCM started the truck initially, but went dead on subsequent attempts. He surmised that fixing this issue would be a dealer-level repair (complete new harness, PCM), and that perhaps the truck wasn't worth fixing. So I had the truck towed back home. Luckily, he didn't charge me a dime, despite the hours he put into it, and the fried PCM he was left with.

My inclination was still that this was a PATS-related issue, and I revisited some of my previously searched bookmarks relative to various vendors who offered "PATS delete" services using one's existing PCM. So, with nothing left to lose, I chose a vendor I had seen on eBay, contacted him to give him the p/n and code for my specific PCM, and he verified he was able to program OUT the PATS module housed within the PCM. Instructions were to send him the PCM, and as long as it wasn't damaged, he'd perform the PATS delete and send it back.

Cut to... I received the PCM back about a week later, plugged it in, turned the key, and "Fakeraptor" once again roared to life! This was back in June, and it has started without issue every day since then.

For those who may see this thread in the future, have the same problem and need to do the same to save their truck, the service was done by Steve Hulett at Drag Radial Performance in Florida, and his eBay listing for the service is under the user-name pontisteve. I can't recommend him too highly. I spoke in detail with him over the phone and he took the time to explain the ins and outs of how these PCMs work, and what he could do to fix it. I chose to have him re-flash it back to bone-stock (with PATS bypassed) with whatever factory updates Ford has provided since originally manufactured.

I hope this helps someone in the future, and once again, thanks to all who took the time to help out.

 

Thank You, for taking the time to update this thread.
I’m sure others will appreciate your solution.

 

Wow what a journey ,Thanks for the feed back . The only thing different i would done is to get the dealer at the time to make me some new keys .

 

Because the PATS is now completely absent, keys can be cheaply cut, now that there is no attempt by the ignition circuit to read a chipped key.