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PATS System going off randomly

Blueox

Member
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6
8
The alarm system is going off on its own at night. Last night it happened five times. Tired of getting up and turning it off at the fob. But I have a thought on what might be happening.

Every so often when when I lock the car with the fob, I get a double bark from the horn rather than a single one. If I remember correctly this is an indication that a door is ajar. When I check the doors they are all secure. So I don't worry about it. I am wondering if one of the door ajar sensors is going bad? Could it be sending a signal to the PATS that an intruder is trying to access the car? Again, it only happens when the car is locked.

Going to test this tonight by leaving it unlocked.
 

bbf2530

Junior Member
698
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43
The alarm system is going off on its own at night. Last night it happened five times. Tired of getting up and turning it off at the fob. But I have a thought on what might be happening.

Every so often when when I lock the car with the fob, I get a double bark from the horn rather than a single one. If I remember correctly this is an indication that a door is ajar. When I check the doors they are all secure. So I don't worry about it. I am wondering if one of the door ajar sensors is going bad? Could it be sending a signal to the PATS that an intruder is trying to access the car? Again, it only happens when the car is locked.

Going to test this tonight by leaving it unlocked.
Hi Blueox. In addition to verifying your vehicle information, just a heads up: The Perimeter Alarm System also monitors the hood and trunk/hatch. So check those sensors too.

Also, if you are not the original owner: Is this the factory alarm system, or is there a chance it is an aftermarket system?

Get back to us with more information, and good luck.
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Blueox

Member
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It is a 2005 Signature Limited. I talked with my friend who is the service manager at a ford dealership and he concurs it is likely one of the sensors. Seeing that it happened 5 times last night he said a scan would indicate which sensor.
 

Blueox

Member
88
6
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Just talked with local dealer. They can read the system and decide what area. They can also turn off the PATS which is what I will do.
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Blueox

Member
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Well dealer cannot figure out which sensor is the culprit. They think the hood latch. They have had it for 3 days. Picked it up Saturday. They had hard wired a bypass for the hood latch. Got it home and all I had to do was touch the hood and it went off. Locked it and waited all of ten minutes and it went off. So back to the dealer. May just want to start throwing parts at it, the hood latch and sensor. They did say that the connector to the sensor was really corroded. So far no charge. They have a one time diagnostic fee of $125 plus tax. If they cannot figure it out, no charge.

Also they cannot turn off the PATS. If they do it would disable the horn and that is not legal. Go figure.
 

Blueox

Member
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Dealer can't figure it out so I took her home no charge. Will replace the hood sensor. Just hoping that will cure the problem.
 

Bob C350

Junior Member
My 2007 used to do the same thing.

Use a generous amount of wd-40 and thoroughly spray each door latch up inside where the door striker hits and do the same for you hood sensor (assuming the dealer didn't screw up the adjustment). Over the years grime and dried grease let's those small micro switch stick especially on the rear doors if they don't get used much.

You'll want to do it a couple times and slam the doors several times between each spray. You may even need to repeat the process a few times over a week or so but I'd bet it fixes your problem. It's pretty common.

Good luck.
 

Blueox

Member
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The new hood sensor arrived yesterday. Installed it and no more random PATS system problems.
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MachMarcus

New member
23
10
3
East Tennessee
My 2007 used to do the same thing.

Use a generous amount of wd-40 and thoroughly spray each door latch up inside where the door striker hits and do the same for you hood sensor (assuming the dealer didn't screw up the adjustment). Over the years grime and dried grease let's those small micro switch stick especially on the rear doors if they don't get used much.

You'll want to do it a couple times and slam the doors several times between each spray. You may even need to repeat the process a few times over a week or so but I'd bet it fixes your problem. It's pretty common.

Good luck.
I had the same thing begin with my 2003 Town Car after long 6 hour drive home in driving rain. Alarm went off four times about 10 minutes after locking the doors. I pulled the horn fuse just to save my neighbors from having to hear it. Sprayed all doors, trunk latch and hood latch/switch. Put fuse back in following day, no alarm. Until this past Thursday, another long road trip in pouring rain, locked door, alarm goes off. Sprayed hood switch and no alarm. I am convinced that the hood switch is the culprit for mine. On the 2003-2005 the hood switch is integrated into the hood latch mechanism. If mine continues, I plan to use a 2006+ switch and install it in place of the one on the latch mechanism since you can't get the switch only and the mechanism is like $60+.
 

Blueox

Member
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Actually my 2005 hood latch is not connected to the PATS. There is a connector on the latch but no wire running to it. The actual sensor is a simple plunger unit bolted to the frame above the radiator. Maybe they changed it mid year. Same sensor as on a mustang.
 

MachMarcus

New member
23
10
3
East Tennessee
Actually my 2005 hood latch is not connected to the PATS. There is a connector on the latch but no wire running to it. The actual sensor is a simple plunger unit bolted to the frame above the radiator. Maybe they changed it mid year. Same sensor as on a mustang.
You are probably right. Ford made changes on lots of cars mid year. I'm going to change mine out to the plunger style if I continue to have an issue with it. Although, the switch acts to cut the electricity to the underhood light, so I wonder if just unplugging the switch would show the PATS system as hood closed (light off) and stop the errors.
 

Blueox

Member
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8
I do not have an under hood light. I guess they eliminated that with the modification to the PATS switch.
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