Why does my car start?! (PATS question)

[Kernle32DLL]

Hi,

While looking for replacement keys (as I only have a single one), I noticed my key does not have a transponder thingy. In fact, its just the raw cut key, no plastic housing at all.

So... why does my car start? From all I have read, this should be impossible? I doubt the thing was flashed with a PATS defeat (would make no sense given the cars history).

 

[Kernle32DLL]

The plot thickens. I picked up a replacement key from a lock smith today, and guess what - it does not work. I see the lock icon flash on the dash, and the car won't turn over. Tried the "bare" key again - works.

That the new key won't work is to be expected - its not programmed in. But why does the "bare" key without a transponder work? Doesn't that kinda defeat the whole purpose of PATS?

 

[Juice]

I have read on the interwebz, that some folks secured a working transponder in the column near the lock. Essentially defeating PATS. Pull the bottom shrowd and see if there is a transponder key hidden under there.

 

[JC SSP]

I initially thought someone disabled the PATS but if there is no transponder in the vicinity (I.e., in the column) how is the car starting with a bare key and why the new key with no programming didn’t start?

 

[86GT351]

I have read on the interwebz, that some folks secured a working transponder in the column near the lock. Essentially defeating PATS. Pull the bottom shrowd and see if there is a transponder key hidden under there.

This. Search the column for this. In theory what you are claiming should not happen without a transponder being there.

 

[TARA-fied1]

This. Search the column for this. In theory what you are claiming should not happen without a transponder being there.

just a dumb question, if there is a transponder hidden, why wouldn't the new key work? Neither have a chip, based on original post, so how does the car know it's not the same key?

 

[Juice]

just a dumb question, if there is a transponder hidden, why wouldn't the new key work? Neither have a chip, based on original post, so how does the car know it's not the same key?

Read post #2 again.

 

[JC SSP]

If car has PATS then new key will need to be programmed.

There is something strange here since the key he’s using is bare with no chip yet he states he has PATS active.

 

[Robert Larimer]

just a dumb question, if there is a transponder hidden, why wouldn't the new key work? Neither have a chip, based on original post, so how does the car know it's not the same key?

Hold on to that working key...it's magic. There is no other explanation.

 

[Kernle32DLL]

Update. Took the whole steering wheel trim off. No hidden transponder....

For fun, I disconnected the immobilizer (the ring thing that is around the actual lock). With it disconnected, neither the bare nor the new un-programmed key work. Connected it again, bare key only working again.

At this rate, I might record a quick video tomorrow to prove my own sanity.

 

[Kernle32DLL]

There you go.

 

[Miker]

I don't know how the system works so just throwing this out there. Is it possible that the chip that comes with the keys default setting is to activate the security system unless it is programmed to work in sync with it? If so would removing the chip allow the key to bypass the security system? Seems like there is no way that is correct as a thief could simply hammer the ignition and start it with a screwdriver if that was the case.

 

[JC SSP]

This is a mystery to me but I am not and alarm/elec specialist so it might be something else…

 

[Juice]

To find the naswer, you need to find out how many keys are stored in the PATS system.
Forscan can read that info. (And program keys)
A non-transponder key should not work if PATS is functional.
A transponder key, unprogrammed should not work, and it does not, check.
If PATS is disabled, the non-programmed key should work, and it doesn't.
That is contradictary, get Forscan.

 

[JC SSP]

Ok take apart the new key and remove the black plastic casing which incorporates the chip. Then use the new bare key to see if it will start.

 

[Midlife Crises]

Is it possible you have a “Master” key. Try the magic key in another Mustang of similar year.

 

[Kernle32DLL]

Seems like there is no way that is correct as a thief could simply hammer the ignition and start it with a screwdriver if that was the case.

Exactly my thought.

To find the naswer, you need to find out how many keys are stored in the PATS system.
Forscan can read that info. (And program keys)
A non-transponder key should not work if PATS is functional.
A transponder key, unprogrammed should not work, and it does not, check.
If PATS is disabled, the non-programmed key should work, and it doesn't.
That is contradictary, get Forscan.

Got it. I need to find out where I can find the programmed keys. So far I only saw options to program in new keys. I will come back to this.

Ok take apart the new key and remove the black plastic casing which incorporates the chip. Then use the new bare key to see if it will start.

I will do that as a last resort, as to not scratch up the casing.

Is it possible you have a “Master” key. Try the magic key in another Mustang of similar year.

Someone next town does have a 05-09 GT. I might get in touch with him.