PATS Armed 2010 Expedition No Start

[Jon1985]

Today i had a weird issue with my Expedition with some running around i had to do today at one point i notice i had a wrench icon on my dash and my transmission would not shift at all so i limped it home. I checked it with my code scanner a U0100 (Lost Communication with ECM/PCM "A") pop up so. i disconnected the battery and i check all the connections to the PCM by disconnecting and reconnecting everything i figured must be a loose connection somewhere but now i cant even start it now the PATS Light is flashing how do i go about resetting this ? Thanks!

 

[stamp11127]

Search "pats" since this pops up now and then. Everything you need to know is in those threads.

 

[Jon1985]

Thank you I did I don’t understand the process then I guess . Both of my keys don’t work do I just leave my key in run for 15 minutes I’m confused this is ridiculous All this from disconnecting the battery it’s very frustrating ....

 

[stamp11127]

The theft light is flashing rapidly because it doesn't recognize the keys & when both keys don't work you are screwed.

Go back over everything you disconnected checking for bent or broken pins.

Reassemble carefully not forcing the connectors.

If nothing was found wrong it is probably time to look at FORscan:
http://www.forscan.org/modules_list.html

 

[Plati]

.... All this from disconnecting the battery it’s very frustrating ....

Of course this is a guess since I dont know how PATS works but if it was my vehicle I'd be guessing the problem root cause was there before disconnecting things and just has a new symptom (PATS wont start) after all the disconnect/reconnect.

do you have remote start? i've had it where key wont start it until i use remote start again

 

[stamp11127]

We have posted how the PATS system works a few times on here and it is explained in simple terms. If the OP doesn't understand certain things on how the system works they can ask for clarification.

Bedrck47 may be gone in body but he is still here in spirit!
Quoting Sam Kinison: Ahhhhhhhhhhhhhhhhhh!

 

[Jon1985]

I Had it towed to my ford dealer they told me the high speed network within my Expedition isn’t Communicating and is down. So they need to check every module within my Expedition to find which one that isn’t working and figure out why it’s not communicating. They said if one goes down they all go down that’s why I’m having a no start .

 

[Plati]

Thanks for following up, seems to make sense. I'm pretty sure all Fords have a CAN BUS ... a high speed communication network. If that goes down, the various subsystems cant talk to each other.

https://www.csselectronics.com/screen/page/simple-intro-to-can-bus/language/en

It does'nt mean MrStamp didn't point at another potential problem since you did some work on your own (plugging/unplugging). Hopefully you mentioned that to the dealer so they know what potentially may be all buggered up.

Worst case you had a computer (ECU) fry or the CAN BUS wiring is compromised. Shop should be able to find that pretty quick.

Let us know how this ends up!

 

[stamp11127]

I teach multiplexing which is what the CANBUS operates on - what they have told you is incorrect. If a module goes down it doesn't communicate with the rest of the modules. Think of it as a student sleeping in class. Do the rest of the students stop learning?

If on the other hand it gets to "running its mouth off" it saturates the network and communication can grind to a halt.

You can sever the network into 2 halves and the modules will still communicate with other modules on that half, just not the half that isn't connected.

I would expect the antenna for the ignition key to be disconnected and not communicating as the root cause.

 

[Plati]

I teach multiplexing which is what the CANBUS operates on - what they have told you is incorrect. If a module goes down it doesn't communicate with the rest of the modules. Think of it as a student sleeping in class. Do the rest of the students stop learning?

If on the other hand it gets to "running its mouth off" it saturates the network and communication can grind to a halt.

You can sever the network into 2 halves and the modules will still communicate with other modules on that half, just not the half that isn't connected.

I would expect the antenna for the ignition key to be disconnected and not communicating as the root cause.

How many CAN BUS's are there in the 2010 Ford Expedition?

If more than one, is there a Gateway?

If you sever the network, do you have to terminate properly to maintain integrity of the differential signal?

Stamp, are you there?

 

[stamp11127]

Not sure about the 2010`s but the 08 i looked at had 3 and a gateway. Two terminators.

 

[Plati]

I think, based on my work experience with communication networks .... the problem here could be as simple as a bad terminator.

https://talk.newagtalk.com/forums/thread-view.asp?tid=695485&DisplayType=flat&setCookie=1

If "I'll be back" comes up in the message center ...

 

[stamp11127]

It has to have both fail for the noise (echos) to squash the communication. It will work with one but not at the rated speed. This is the same star networking as the internet uses except running under different protocols. I teach J1507, J1708 and J1939 at an intro level.