theft light flashing no start sometimes

03sonicvert

New Member
Aug 9, 2019
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myrtle beach
I was wondering if anyone could help me with this problem my car is having. Some days my car runs perfect wihtout a single problem and then other days whenever im driving my theft light starts flashing then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off. And usually whenever that happens the next time I go to start my car its like it is dead and the theft light flashes. Ive had both the battery and alternator checked out and they test perfect. If anyone has any advice it would be greatly appreciated thanks.
 
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wmburns

SN Certified Technician
Aug 14, 2009
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Houston Texas
Ford factory PATS will not disable the motor once the motor has started. With that thought in mind the blinking theft light is not THE problem but a symptom of the problem.
then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off.
^^^This is the important clue^^^ My vote is there's some power "issue" that is "causing" the PCM and ignition to "sputter".

This same power problem is also rearing it's head that prevents the motor from restarting. Remember that it takes a data exchange between the PCM and cluster. Sooooooooooooo if there's a problem either in the cluster or PCM this will cause the PATS exchange to break down.

If this were my car I would start with a through review of the battery and charging system. Don't stop at just looking at the battery and alternator. Review all of the connections and grounds.

Howto perform charging system voltage drop test

When you are sure that the charging system is in tip top shape, now we need a way to monitor the voltage while the car is moving. Suggest getting yourself an "add a circuit" this will offer a way to attach a VOM where it can be placed where it can be seen while driving. For example fuse F2.2 or F2.8. Testing here will give an idea of the function of the CCRM.

1999-2004 MY fuse panel schedule:

1996+ Crank with no start check list
 
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Necoler1

New Member
Nov 27, 2019
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I was wondering if anyone could help me with this problem my car is having. Some days my car runs perfect wihtout a single problem and then other days whenever im driving my theft light starts flashing then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off. And usually whenever that happens the next time I go to start my car its like it is dead and the theft light flashes. Ive had both the battery and alternator checked out and they test perfect. If anyone has any advice it would be greatly appreciated thanks.
Did you find a solution? My 2004 is doing the exact same thing. Theft light was flashing car sputtered and jerked off when backing into garage. Theft light stays blinking car wont start. Tried turning wheel, rubbing fobs against stereo speaker and locksmith came out and reset keys. Car still wont start.
 

Potomus Pete

Gretchen Whitmer is eating at me
Mar 7, 2019
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This guy joined , asked the question , and never returned . All in one day . When possible, it is important to give a full explanation of what the fix was . Electrical problems stink .
 

wmburns

SN Certified Technician
Aug 14, 2009
5,849
507
204
Houston Texas
Theft light was flashing car sputtered and jerked off when backing into garage. Theft light stays blinking car wont start. Tried turning wheel, rubbing fobs against stereo speaker and locksmith came out and reset keys. Car still wont start.
Are you looking for an educated guess?

Your problem is NOT anti-theft (PATS) related. How do I know? Because Ford factory PATS will NEVER shut off the motor once it has started.

IMO you should look at a PCM base electrical problem first as the cause. Remember that PATS requires a two way exchange of data between the cluster and PCM. So IF something interrupts power to the PCM while the car is in motion that would cause the motor to stumble. Plus this could also re-drive the PATS exchange.

1996+ Crank with no start check list

Pay attention to the role that:
  • A loose PCM or CCRM ground could play in the symptoms
  • The role that a bad ignition switch could play. IE, check fuse F2.34.
 
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232937

New Member
Jun 10, 2019
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palm springs ca
I was wondering if anyone could help me with this problem my car is having. Some days my car runs perfect wihtout a single problem and then other days whenever im driving my theft light starts flashing then the car starts to sputter and jerk and while that happens all the lights on my dash start to flicker on and off. And usually whenever that happens the next time I go to start my car its like it is dead and the theft light flashes. Ive had both the battery and alternator checked out and they test perfect. If anyone has any advice it would be greatly appreciated thanks.


DUDE I had the same problem and I know you said the battery was fine but get a new battery then see what happens im 90% sure you will solve your problem ny battery tested ok also..