Randomly stalling?

2005 FORD TAURUS
70,685 MILES • 3.0L • 6 CYL • AUTOMATIC
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BOCCIGALOOPI6
I have had a stalling issue with my car listed above. I have had 2 mechanics that can't seem to find the reason why as there wasn't any codes or engine light showing. I bought a blue tooth scanner, and it did come up with codes. #1 U2023, #2 P0300, #3 P0316. I looked these codes up and I can't make hide nor tail out of any of it. I am at my wit's end, with a depleted bank account. I can't afford to put any more money into this car which I love. It is like parting with an old friend. I have had tune-ups, fuel filter replacement, MAF, IAC valve replaced also crankshaft synchronizer. Yes, I know as a 70-year-old woman they seen me coming. Would you have any insight or solutions to this issue? I forgot to add that my Taurus starts right up in the morning no hesitation, runs smooth and quiet for a while, then shuts down without warning. The crazy thing is it will start right back up again like nothing ever happened? My biggest fear is it will stall and cause an accident. I thank you for any help you can give me. Help!
Nov 29, 2024 at 12:29 AM
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STRAILER
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So the first code, U2023, is the one to fix first which can be a low voltage error, can I ask how old the battery is? I have seen a battery short out internally and then work again instantly FYI.

U2023 - Fault Received from External Node:

P0300 - Random/Multiple Cylinder Misfire Detected:

P0316 - Misfire Detected on Startup (First 1000 Revolutions):

Please go over this guide:

https://www.2carpros.com/articles/engine-stalls

If the battery is new, I would look at the ignition switch which can heat up and disconnect and then cool down and start working again. These kinds of problems can be hard to find but if we go step by step on the most popular items that can make this happen, we should be able to fix it. Check out the images (below). Please let us know what happens.
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Nov 29, 2024 at 6:33 PM
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BOCCIGALOOPI6
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Thank you for the quick response. I bought the battery in 2020 at AutoZone. It is a Duralast battery. What is the voltage a battery should be when the car is off/running? Question about the ignition switch once it causes car to stall will it restart immediately? When it stalls, I put the car in park turn the key and it starts right away. Thanks again for answering. Have a great day.
Nov 29, 2024 at 10:34 PM
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BOCCIGALOOPI6
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Maybe it's time to look for a new car. :o(
Nov 29, 2024 at 11:12 PM
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STRAILER
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Sure, here is a guide that will help you test the battery voltage and the alternator output:

https://www.2carpros.com/articles/how-to-check-a-car-alternator

These kinds of problems can be tough. It can be the fuel pump, crankshaft sensor, bad connection at any of the electrical components. We need to see what the engine is missing when it stalls, fuel or ignition, please go over this video to help:

https://www.youtube.com/watch?v=lXLJbuAZ4CE&t

We can try the most popular items before you look for a new car. Please go over this guide and get back to us. Also go over the guide above to see the list of the most popular items that can cause this kind of problem.
Nov 30, 2024 at 11:24 AM
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BOCCIGALOOPI6
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Ken,

There are no warning lights to test. Nothing indicates a problem at all it is what makes this so frustrating. I did locate a receipt from 2021 for a rebuilt alternator. Is it possible it's failing without sending a warning light? Just curious, could faulty alternator be able to restart after the stall right away. Thank you for your time and input, it is much appreciated.
Dec 1, 2024 at 8:00 AM
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STRAILER
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The alternator will probably not cause the car to stall. Let's try replacing the PCM power relay which can cause this issue and is a cheap and easy fix. Here is the location of the relay so you can swap it out. Check out the images (below). Let us know what you find.
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Dec 1, 2024 at 10:38 AM
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BOCCIGALOOPI6
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Okay, Ken, where is the PCM power relay located? is it under the hood on the right side or on the left under the steering column? Where can I buy one? AutoZone or any car parts store?
Dec 1, 2024 at 10:44 AM
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BOCCIGALOOPI6
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Ken,
Does PCM stand for Power Control Module or Powertrain Control Module or are they the same thing?
Dec 1, 2024 at 10:50 AM
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BOCCIGALOOPI6
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Thank you for your patience and aid in trouble shooting. It really makes me hopeful. :o)
Dec 1, 2024 at 10:52 AM
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BOCCIGALOOPI6
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Good Morning, Ken,

The fuse box diagram in the book that came with the car is different from the one you sent me. I tried to attach it, but it said image not allowed. Anyway, the PCM power relay is colored green and has a number 30 on it, I found it at the Ford site www.startmycar.com if that helps you to see what I mean. Have a great day and thanks again for all your help.
Dec 2, 2024 at 2:20 AM
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BOCCIGALOOPI6
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Ken,

Hi, me again. I think I understand it now. The green #30 was a fuse and the PCM power relay is in the same position as in your diagram, but my book has a different number #31.
Dec 2, 2024 at 4:14 AM
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STRAILER
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Did you click on the image above to see the PCM relay location?
Dec 2, 2024 at 10:07 AM
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BOCCIGALOOPI6
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Ken,

I finally drove my car to the AutoZone and the employee Terry changed the PCM power relay right there. I have been driving it, and I am afraid to say; it may work! So far it hasn't stalled at all, and I remain cautiously optimistic. The part including the tax was less than $10.00! I thought I must be dreaming. I will drive it around this week to make sure and let you know one way or another. Thank you again for all your time. You have truly been a blessing in all my craziness. :o)
Dec 2, 2024 at 10:22 AM
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STRAILER
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You are welcome, but you have the right idea, drive it for a couple of days, and if it goes on for about two weeks then we can say that was the problem. Wish us luck! :)
Dec 3, 2024 at 8:29 AM
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BOCCIGALOOPI6
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Hello again Ken,
One more thing, I ran another scan and the only code that came up was P1000. I was told to just drive my car for 2 weeks 50-100 miles, and it should reset itself. Is this the right thing to do?
Dec 3, 2024 at 12:43 PM
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BOCCIGALOOPI6
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Ken,
You may get this twice I couldn't see what I wrote so I sent it again.
Dec 3, 2024 at 12:45 PM
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BOCCIGALOOPI6
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Ken,

Was too good to be true, drove for 2 days no stalling 3rd day it stalled. I drove around 17 miles all was fine. Suddenly "theft light" flashed once. I drove a bit more and headed home just as I pulled into my parking space it shut down. If it was the PATS the car wouldn't start at all would it? I am very :0(. Could it be a glitch in the electrical system? Where does one start when the only code is P1000 FF? Any ideas would be so appreciated.
thank you kindly,
Debee
Dec 4, 2024 at 6:27 AM
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STRAILER
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This code means that the vehicle’s On-Board Diagnostic (OBD-II) system has not completed all the self-tests since the last time the codes were cleared. You said the security light blinked on before it stalled? This can be a clue.
Dec 4, 2024 at 10:15 AM
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BOCCIGALOOPI6
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What would make the theft light flash once? It didn't stall right away. But it always seems to restart immediately, right after it stalled. Should I have the electrical system checked by Ford auto repair? Is it worth going down another rabbit hole? I'm being a pest, aren't I? Anyway, thank you for all your help, have a Merry Christmas and a safe and Happy New Year. Wishing you and your family God's blessings.
Dec 4, 2024 at 11:54 AM
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STRAILER
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Hi Debee, never a pest :) I am leaning toward the PCM now, with the code:

U2023 - Fault Received from External Node:

So, there are no other codes, correct? We need to see which system is failing, either fuel or spark, please go over this guide to run the codes again and a video to see what to check for when the engine stalls.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and this video shows what to look for, but this will be difficult because it starts right back up.

https://www.youtube.com/watch?v=lXLJbuAZ4CE&t

There should be a data recorder box the garage can connect to read the stream to see what stops working, I would call around until you find a shop that has one or we can keep replacing the popular parts that can cause this. You can get a preprogrammed PCM unit by searching Google or Ebay. Here is how to change it out. Check out the images (below). Please let us know what happens.





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Dec 5, 2024 at 12:32 PM
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BOCCIGALOOPI6
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Good day Ken,
Guess what, I had taken my car to Firestone. It turned out the previous mechanic only cleaned the MAF Sensor, so Firestone replaced it only the one they replaced it with turned out to be a bad one. I drove my car yesterday for 14 miles without it stalling though. Took it out later it stalled at every red light. maybe 6 times had to drive it home with hazard lights flashing. Anyway, Firestone will replace it this morning. I don't know if it will help though. I have learned enough about my car to know the MAF sensor is very important. Thank you for responding again.
Dec 6, 2024 at 12:05 AM
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STRAILER
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I was going to suggest the MAF sensor but I thought it had a new one. That can cause the problem, let me know how it goes and have a good weekend!
Dec 6, 2024 at 9:49 AM
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BOCCIGALOOPI6
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Ken,

The only code it shows now is P1000. Firestone replaced the bad MAF sensor, it drove fine for a while and started to stall again. I gave up on it. My last resort would be to take it to Ford, and they will charge more than the car is worth. I appreciate all your help. :o)
Dec 6, 2024 at 3:56 PM
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BOCCIGALOOPI6
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Hello Ken,
I have just one more question, could a PCV valve on its way out cause my car to randomly stall? My nephew suggested it as he worked at car dealership as a mechanic a few years back. Your thoughts on this would be much appreciated. Thank you have a good day.
Debee
Dec 6, 2024 at 11:50 PM
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STRAILER
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Hi Debee,

Not while driving, I would try the PCM as one last attempt. They are not too much, and I think it is worth a shot.
Dec 7, 2024 at 12:24 PM
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