Where is the PCM and how to check it?

1998 LINCOLN TOWN CAR
130 MILES • 4.6L • AUTOMATIC
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ROBBYNMAE
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I have codes p0352 p0352 p0353 p0357 I have replaced all ignition coils and spark plugs, still had codes. Replaced valve cover gaskets because there was oil in the spark plug wells, still same codes, I exchanged ignition coils with 1 & 4, same codes. I examined the wiring harness, checked the ignition coil connectors with a multimeter, all readings were fine. Still same codes. So I heard that I need to check the pcm. I cannot find it. Where is it, please? Do you have any ideas on what I should do next?
Jul 14, 2026 at 8:15 PM
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AL514
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Hello, so you have the same code twice there, but I am assuming the codes are P0351, P0352, P0353, and P0357. If that is correct, I do see something in common with those ignition coils that is the other 4 coils are not part of. Cylinders 1,2,3,7, ignition coils run threw the C127F/C127M connector, whereas the other cylinder's coils do not run threw that connector on the control side, I think that is where you will find the issue. Ill post the oem wiring so you can see what I mean.
Jul 14, 2026 at 11:22 PM
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AL514
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You can see this connector is on the control side of each coil setting a code, so we need to find it. You can try tracing the wire colors back until you find the connector, but Im not sure how many wires are in it, so let me see if I can find it in service info.
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Jul 14, 2026 at 11:26 PM
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AL514
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Hopefully this will help you find the problem, look for this big bulk connector, most likely there is a pin issue or corrosion inside. But let us know what you find.
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Jul 14, 2026 at 11:51 PM
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STRAILER
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Great post AL514!
Jul 15, 2026 at 12:16 AM
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ROBBYNMAE
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Thank you very much! Yes, I did mistype in my last message. You are correct.
Thank you for the information. You have by far, given me the best detailed information, than any human or AI. I appreciate it!
I’m off to follow your instructions. I’ll let you know how it works out. Thank you again!
Blessings
Jul 15, 2026 at 12:37 AM
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AL514
  • ✓ASE Certified Mechanic
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  • ASE Certified Mechanic
Glad to help. Look deep into the pins inside that connector, check the females pins as well, that they are not spread apart making poor contact.
Jul 15, 2026 at 12:52 AM
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