PCM pinout?

Tiny
CHUCKHOTROD
  • MEMBER
  • 2003 FORD MUSTANG
  • 3.8L
  • V6
  • 2WD
  • AUTOMATIC
  • 132,000 MILES
Two towers not firing on coil. I discovered there is no ground signal at the coil for those two towers that fire cylinders three and four. I want to check continuity from PCM to coil before buying a new PCM.
Tuesday, November 20th, 2018 AT 1:21 PM

6 Replies

Tiny
WILLIAM CRABTREE
  • MECHANIC
  • 95 POSTS
Hello,

I have attached several diagrams based on the vehicle information you provided.

Let me know if you need any more info or more diagrams!

William
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Tuesday, November 20th, 2018 AT 8:22 PM
Tiny
CHUCKHOTROD
  • MEMBER
  • 3 POSTS
Thanks Mr William your a lifesaver!
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Wednesday, November 21st, 2018 AT 8:45 AM
Tiny
WILLIAM CRABTREE
  • MECHANIC
  • 95 POSTS
Delighted to help!

Thanks for using 2CarPros!
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Wednesday, November 21st, 2018 AT 9:01 AM
Tiny
CHUCKHOTROD
  • MEMBER
  • 3 POSTS
Pin 78 was in a different location then the diagram had it but I figured it out beings the connector was numbered.
I been a tech for over 35 years whatever happened to books good Lord its an act of God to repair these dang cars even with a $5,000.00 snap on scanner without diagrams your just out of luck (lol) all three coil drivers wires from PCM to coil have continuity so it is PCM time.
Might you know if vats goes through the PCM on this thing or just the GEM module? I cannot get a clear answer anywhere being it is an 2003 Ia m unsure as I remember sometime in 2004 Ford changed protocol on these mustang PCM's I do know the new protocol does in fact go thru the PCM.
My scanner has bi-directional controls and I can program keys but not sure they Will take on a used PCM, I found one with all numbers matching to a tee but again it is a 2003.
Thanks for all the help.
Chuck
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Wednesday, November 21st, 2018 AT 1:47 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,654 POSTS
Hello,

Here are the engine wiring diagrams so you can see how the system works. Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

Cheers, Ken
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Friday, November 23rd, 2018 AT 11:20 AM
Tiny
HOTSTANG
  • MEMBER
  • 29 POSTS
I dropped an old school 5.0 into a 1997 Stang. I'm attempting to hook up a tach adapter off my HEI distributor. I'm trying to locate where the signal wire is on c104f connector, I believe that is connector where engine harness plugs into. I'm hooking up a Glow Shift HEI adapter. The car originally had a 3.8L.
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Monday, September 5th, 2022 AT 10:26 AM

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