Well here is the problem, my 01 screw in the last few days will not start, you can drive it all over town with no problem and then it will not start, I do have an after market alarm system with an auto start on it and that was installed in Feb. of this year. So if I park the truck even over night I can remote start the truck and will not start(sometimes) reset the alarm and restart it again and it will start. So one day I was in the truck, shut the truck off went into the store with out setting the alarm system got into the truck and went to start it and it would not start, I noticed that the THIEFT LIGHT on the dash was flashing even when I went to start the truck with foot on brake, nothing.
I sat in the truck a few minutes and went to start it again and the THIEFT LIGHT went out and the truck started, but I noticed when I put my foot back on the brakes is when it went out, has anyone had this problem and if so how can I fix this ASAP..

 

Do you have another RFID tag on your key ring ?
( Mobil speed pass, another PATS key, etc )

Not sure how the aftermarket Alarm / RMST did the PATS bypass, if the key is only the Ford key, and you are having problems, could be the PATS transponder.
This is around the ignition key cylinder.

Try starting with only the key programmed for the truck ( not on a key ring ) and try the other key for the truck also, to see if it acts the same.

Have you had this problem when it was warm out ?

There was a tech tip on the PIK3 PATS bypass in cold weather, where the newer IPATS signal strength is lower than the previous EPATS signal strength.
Don't think this applies to your MY truck, but is why I asked about the temperatures when the symptoms happen.

 

The remote starter pad and the truck key are on the same key ring, I will remove and see if that cleares it up but since it is colder out here live in victorville ca., is when it has been doing it.

 

So my wife and I have been driving the truck around now without using the new remote and alarm system at all and also seperated the remote from the truck key too and with all that done we have had no starting problems. So now Im going to go back to the shop that installed the system and tell them to fix the problem or take out the system all together and want my money back..

 

Ok so I have had just been using the factory key to lock and unlock my truck and its been going good until now, the truck will not start and the thieft light is staying on and I think is keeoing the truck from starting, is there any way to disconnect the thieft light nad where is it at.

 

Nope, that is the reason it is an Anti-Theft.

It should not be the case, but I would look at the aftermarket RMST install.

The PATS key should be the one that gets read, but depending on the RMST install ( some use a programmed key with the lock part cut off ) this could be reading as 2 different RFIDs, causing PATS to read it as a invalid key.

What is the type of PATS bypass on the aftermarket RMST ? ( key in the box type or the PIK3 PATS bypass type ).

 

So I went and pulled the dash apart on my truck and found the remote start box and the main box for the new system that was installed and so I pulled the main box out and unpluged it and the truck started, no more thieft light on when I went to start it too.

 

Let's keep an eye on it, and see if it happens again.

Please give us an update in 2 weeks at most.

 

Well it would not start again and now the fuel pump is out so I replaced the pump and filter my self and its running alot better, but will keep an eye on it for a few days to see if it does it again..