Anti theft system problem

98SaleenCobra · Jan 10, 2004

I have a problem with my anti-theft system. When I insert the key and turn it to ON, the theft light flickers and the car won't start. It will crank, but not start. Also, the fuel pump comes on, but never seems to pressurize, and never shuts off. I have suspected the key, but I'm not sure. Does anyone have any ideas on what it may be? Thanks.

Oh, the car is a '98 Saleen Cobra. Don't know if Cobras are set up different as far as the computer and/or anti-theft system.

Jason

claytucc3 · Jan 10, 2004

Sounds like the key to me. Peeps on here are hesitant to answer anti theft problems. I has one and people were accusing me of all kinds of stuff. But yeah it sounds like the key. Have you accidentaly switched it. Also, try using both sides of the key.

teesgt · Jan 10, 2004

My anti theft module went out on mine. The engine would just spin over but never fire. I would try the key first, if that didn't work, I would check the anti theft.

Sam98 · Jan 10, 2004

98SaleenCobra said:
I have a problem with my anti-theft system. When I insert the key and turn it to ON, the theft light flickers and the car won't start. It will crank, but not start. Also, the fuel pump comes on, but never seems to pressurize, and never shuts off. I have suspected the key, but I'm not sure. Does anyone have any ideas on what it may be? Thanks.

Oh, the car is a '98 Saleen Cobra. Don't know if Cobras are set up different as far as the computer and/or anti-theft system.

Jason

The PCM should turn the pump on for a couple of seconds to pressurize the line then shut it off. When you said it doesn't seem to pressurize are you guessing or do you know the fuel system isn't pressurizing? If the PCM senses that the fuel system isn't pressurizing like it should, it will disable the car the same way it does when the PATS doesn't prove out. Maybe your fuel pump is shot. Otherwise, it sounds like the PCM...do you have a chip on there? Mine will do that if I have my tweecer in the wrong position, so a partly seated chip should be able to cause similar symptoms. If the problem were with your PATS module the fuel pump would still function normally. The theft light would come on, then start flashing rapidly, and you can crank the car all day but it would never start, and the fuel pump would never turn back on without cycling the key.

98SaleenCobra · Jan 11, 2004

Sam98 said:
The PCM should turn the pump on for a couple of seconds to pressurize the line then shut it off. When you said it doesn't seem to pressurize are you guessing or do you know the fuel system isn't pressurizing? If the PCM senses that the fuel system isn't pressurizing like it should, it will disable the car the same way it does when the PATS doesn't prove out. Maybe your fuel pump is shot. Otherwise, it sounds like the PCM...do you have a chip on there? Mine will do that if I have my tweecer in the wrong position, so a partly seated chip should be able to cause similar symptoms. If the problem were with your PATS module the fuel pump would still function normally. The theft light would come on, then start flashing rapidly, and you can crank the car all day but it would never start, and the fuel pump would never turn back on without cycling the key.

I suppose I'm guessing as to whether or not the fuel pump is pressurizing. Here's how the whole thing goes. I turn the key to ON, and before I ever even try to start it, the fuel pump comes on like normal, but never quits whining....like its attempting to pressurize. I can leave the key in the ON position for minutes and still it never stops. At the same time, and only a few seconds after turning the car ON, the anti-theft light begins to flash rapidly, and I don't even bother to attempt to start it, cause its not gonna happen. It will just crank.

What I'm not sure of is if the fuel pump will cause the anti-theft system to shut down, or if the problem starts at the anti-theft. Know what I mean?

I'm not sure what the PCM is. And the chip you were referring to, do you mean a performance chip? If so, yes the car has one from Saleen. I'm also not sure what a tweecer is.

From what I have decribed, do you think the fuel pump, or the anti-theft system is the most likely culprit.

Thanks alot.

Sam98 · Jan 11, 2004

98SaleenCobra said:
I suppose I'm guessing as to whether or not the fuel pump is pressurizing. Here's how the whole thing goes. I turn the key to ON, and before I ever even try to start it, the fuel pump comes on like normal, but never quits whining....like its attempting to pressurize. I can leave the key in the ON position for minutes and still it never stops. At the same time, and only a few seconds after turning the car ON, the anti-theft light begins to flash rapidly, and I don't even bother to attempt to start it, cause its not gonna happen. It will just crank.

What I'm not sure of is if the fuel pump will cause the anti-theft system to shut down, or if the problem starts at the anti-theft. Know what I mean?

I'm not sure what the PCM is. And the chip you were referring to, do you mean a performance chip? If so, yes the car has one from Saleen. I'm also not sure what a tweecer is.

From what I have decribed, do you think the fuel pump, or the anti-theft system is the most likely culprit.

Thanks alot.

The PCM is the computer that determines when and if your coil packs fire, fuel pump turns on, injector pulse width, monitors all of the engine control systems, etc... It is located in the kick panel on the passenger side. The tweecer is a chip that plugs into the diagnostic port (just like yours) but can be programmed while in the car. I'm pretty sure your problem is not the PATS. If it were the fuel pump would operate normally. It cost me $1000 to find that out while the moron at the local Ford dealer "easter egged" his way through the system (replacing each component at my expense) only to discover the PCM was to blame. Then the retard ordered the wrong one...

The first thing you should probably do is connect a fuel pressure gauge and see if you are getting pressure. If so, you probably need to run diagnostics on the PCM...

98SaleenCobra · Jan 11, 2004

So how does the anti-theft system keep the car from starting? I assumed that it did so by cutting off the fuel to the engine, since the engine still cranks.

One other thing to mention: The day that the car decided it would never start again, was a day that I drove the car hard (couple of rice burners needed a leeson) and it was pretty cold. (Around 20). This had happened before, but the car would always eventually start...until now.

Sam98 · Jan 11, 2004

98SaleenCobra said:
So how does the anti-theft system keep the car from starting? I assumed that it did so by cutting off the fuel to the engine, since the engine still cranks.

One other thing to mention: The day that the car decided it would never start again, was a day that I drove the car hard (couple of rice burners needed a leeson) and it was pretty cold. (Around 20). This had happened before, but the car would always eventually start...until now.

The same way it is here: the fuel pump is disabled, no pulses are sent to the coil packs or injectors, and the theft light flashes. There are a number of things that can cause the PCM to do this, not just the PATS. If the PCM detects that the fuel line does not pressurize as it should it assumes the fuel line is open and kills the pump. Since the pump is continuing to run it sounds like the PCM cannot control the pump. That can happen if the chip is not correctly seated because the chip then effectively corrupts the operating system. My guess is that if you hooked up a code reader, it would fail to communicate with the PCM, but you should verify whether or not your fuel pressure is good. The regulator should keep it around 35-40psi.

98SaleenCobra · Jan 12, 2004

And if it doesn't pressurize, then is it more than likely the fuel pump? Do you happen to know anywhere that I could get a list of the error codes and what they mean?

By the way, I appreciate the help.

Sam98 · Jan 13, 2004

http://www.obdii.com/

Try this...

awwyea · Jan 13, 2004

My 99 GT will do this occassionally as well, I found that I have to press the unlock button on the factory remote twice. Then the car will start.

98SaleenCobra · Feb 8, 2004

I appreciate all the help everyone gave, it is/was much appreciated. As it turns out, it was the performance chip. The computer couldn't read the chip, so the car wouldn't start. Now I just have to get the chip replaced.

dsb567 · Jan 8, 2009

Did U ever solve your problem???

I am having the same problem on my 2004 mustang. It just startedhappenning. The car just turns over but will not start. e-mail me if you can help
shakespear871@yahoo.com
thanks so much.

98SaleenCobra said:
I have a problem with my anti-theft system. When I insert the key and turn it to ON, the theft light flickers and the car won't start. It will crank, but not start. Also, the fuel pump comes on, but never seems to pressurize, and never shuts off. I have suspected the key, but I'm not sure. Does anyone have any ideas on what it may be? Thanks.

Oh, the car is a '98 Saleen Cobra. Don't know if Cobras are set up different as far as the computer and/or anti-theft system.

Jason

85 Coupe 5.0 · Jan 8, 2009

dsb567 said:
I am having the same problem on my 2004 mustang. It just startedhappenning. The car just turns over but will not start. e-mail me if you can help
shakespear871@yahoo.com
thanks so much.

In addition to what you have read here I have some info.

I have done a lot of these at work for this issue. Most of the time I find that from years of moving the tilt column up and down the PATS module wires at the base of the column get pulled and severed. A good way to test this is when it's acting up, move the tilt wheel all the way down and try again. Make sure you turn the key off, move the column and re-try. Even then, sometimes the wires completely pull out. In this case you'll need to remove the column shroud and knee bracing panel to inspect.

As always, if you have an aftermarket chip, try removing it 1st.

Regardless of what has been posted, don't even bother checking fuel pressure, ect. if the theft light flashes. If it's not on solid when you turn the key on, you have a PATS issue.

Just my experiences at my day to day life at the dealership.

Notchbck93 · Jan 9, 2009

85 Coupe 5.0 said:
In addition to what you have read here I have some info.

I have done a lot of these at work for this issue. Most of the time I find that from years of moving the tilt column up and down the PATS module wires at the base of the column get pulled and severed. A good way to test this is when it's acting up, move the tilt wheel all the way down and try again. Make sure you turn the key off, move the column and re-try. Even then, sometimes the wires completely pull out. In this case you'll need to remove the column shroud and knee bracing panel to inspect.

As always, if you have an aftermarket chip, try removing it 1st.

Regardless of what has been posted, don't even bother checking fuel pressure, ect. if the theft light flashes. If it's not on solid when you turn the key on, you have a PATS issue.

Just my experiences at my day to day life at the dealership.

That is great info for anyone trying to do a quick diagnosis. Of course step one is to panic that the car won't start and step two, is to get all upset LOL.

gip99drop · Jan 9, 2009

Anti-theft module has gone bad, my 99 did the same thing. Had to get me keys re coded too.

BlownStangGT · Jan 10, 2009

I had this happen to me once but it was the key....Mine has an aftermarket alarm installed though. I just grabbed the other key and she fired right up. Not sure

Brandon Morris · Mar 16, 2013

Ok so after reading all the replies to this one, it peaked my interst of curiousity. Just last week I was driving my 2004 V6 and it just stopped running and acted as if it was chocking to get gas to the engine. So I had it towed to my mechanic and he claims it was the fuel pump that went out. He ordered the part, replaced and started the engine, it started up and then he disconnected my progressive snap shot and tried to do a code reader for more details of a diagnosis. The anti theft device kicked in and shut everything off. Now the car will not start. So as dsb567 said if the theft light is not solid it is a PATS problem. What does this stand for anyways? As of right now the car is at the dealership awaiting more confusion details as to what happened.

Luvmelotztina · May 11, 2015

85 Coupe 5.0 said:
In addition to what you have read here I have some info.

I have done a lot of these at work for this issue. Most of the time I find that from years of moving the tilt column up and down the PATS module wires at the base of the column get pulled and severed. A good way to test this is when it's acting up, move the tilt wheel all the way down and try again. Make sure you turn the key off, move the column and re-try. Even then, sometimes the wires completely pull out. In this case you'll need to remove the column shroud and knee bracing panel to inspect.

As always, if you have an aftermarket chip, try removing it 1st.

Regardless of what has been posted, don't even bother checking fuel pressure, ect. if the theft light flashes. If it's not on solid when you turn the key on, you have a PATS issue.

Just my experiences at my day to day life at the dealership.

Help of you can ford dealership had had my 98 cobra for theft light staying on and not starting. 4 months now and they can't figure it out

New key programmed, eec relay replaced, and whatever else they continue to charge me for.
I know everyone is saying pats is the issue.... If ford isn't figuring it out. Any one else have ideas my husband and I are going nuts over this!

Thanks Tina

wmburns · May 12, 2015

How about getting yourself a hand held tuner? Get and load a "custom" tune with PATS disabled. If it is a PATS issue, then disabling in a tune will allow the car to be started and driven.

To anyone else reading this thread, always do this when reporting a possible PATS issue. Turn the key on but do NOT crank. The theft light should come on and then go out after a 3 second "prove out".

If the PATS system does not "prove out", remove all other metal objects and try just the key all by itself.

If the PATS system passes the "prove out" test and the motor still cranks with a no start, then suggest looking elsewhere for the problem.

For the 1996+ Model year PATS system:

Factory PATS does NOT disable the fuel pump. It works by withholding the injector pulse. So if the fuel pump doesn't run at initial key on, it isn't a PATS problem. For the same reason if there's no fuel pressure, then it's not a PATS issue.
Factory PATS does NOT shut off the motor once it starts. So if the motor starts and then quits, this is not a factory PATS issue.

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