This belongs in it's own thread as this question has come up, so some of this may seem familiar...

Since I based my work on mostly 2003 diagrams I will conclude that this procedure will work on a 2003 -2004 "retail" panther aka a P-73/P-74 and Grand Marquis. Should work on a Town Car but the starter relay location may be different.

This will also only work keeping the same year PCM as the car, the 2004 PCM won't work on a 2003 due to the transmission having a different tooth count on the OSS Also this process (Edit DOES WORK) MAY work on a 2005 up but with the CAN BUS system there may be many other problems, the PATS and starter interrupt circuits are probably the same or at least similar.

I started this in response to my PATS or the PCM failing and cutting the engine off but this swap is worthy even with a good running car as this deletes the PATS and can cost the same as getting a new key made, and of course to add the 80 MM MAF and Zip tube to a Retail 2004 to add 11 HP!!

First step is to swap the PCM, I found a 2004 P-71 2-04 build date and the PCM code matched the sticker on the door jam.




Since the 2004 P-71 also has the famous Zip tube and the 80 MM MAF with the 2005 up style blade MAF you gotta swap this over as well. As you see above I got a few 8 pin harness plugs so I can swap over the MAF pigtails if I want to run the stock PCM again or use the MM style MAF.

So I installed the 2004 P-71 airbox and Zip tube I already had, oh yeah the P-71 box is not for sale anymore now, I was already keeping the Zip Tube. Now I gotta put the spare MM airbox/MAF up for sale, but I plan to test it out on the car first to see if it would work with the P-71 computer.


Everything installed Reconnect the battery KOEO and CEL comes on the PATS light never blinks or makes any signal. Turn to start and no crank!!!!

Checked the harness in many places everything looks fine. I could not find any proper pinouts for a 2004, the 2004 DVD image I have only has 1 2004 model in it Feb 2003 edition.

Dejected with failure I come back in and search frantically for a possible answer and find this one...




So armed with this info I could not find any pinouts for the power distribution box. I was able to gleam enough from the 00-04 DVD to find the pin assignments for the starter relay.

So using the famous ISO diagram




86 = Start signal from ignition switch, power to Relay coil

85= Ground signal from PCM, Ground for relay coil.

30= 12V unswitched from battery, Current feed for switched power.

87A unused

87= power output to starter, Switched power output from relay

Did find the Dist box layout, but this is in my owners manual too



Could not find the diagram for the box, or the schematic of the wires the colors etc.. so plowing forward you see the classic ISO relay layout on the pins for the large 1" relay section.

And look at the Dist box, but noting the tabs marked on the relay ,the above diagram is "backwards" the view is looking at the relay unplugged from the dist box like in your hand

Ha this picture would have helped last night explains my point better.



So I removed the bottom of the dist box and found the wire for circut #57 leading from the #85 pin on the relay.
The #57 circuit is a grey/pink wire and its on the "top" of the bundle pretty much the only wire you can touch leading into the wrapped bundle., but pulling the bottom of the dist box off is pretty much needed to access the wire.

You see this jumper which is attached to the Neg cable.


I confirmed the 12V at pin 30 and #86 is 6V key off then 12V when turned to start. Ok, so plug in the relay go in to the car and...


SHE RUNS!!

Better shots of the Distribution box



Just a few wires, not at all intimidating You can see the wire I cut and the wires for the relay are all visible.


The ground wire all routed properly and the Dist box reassembled.



Added a terminal end and attached properly along with the ground strap from the negative terminal to body cable. Don't want this coming loose 500 miles from home. Routed all clean



The MAF pigtail attached to the 8 pin



Temporary crimps I ran out of 22-18's



Replaced the crimps and wrapped it up with 3M tape


The harness tucked away, gotta cut off the stuck mount studs from the airbox and replace em with new ones. Then I will zip tie down the harness better.



All back together and cleaned up some, you do need the 80 mm zip tube to fit over the bigger MAF



Here is the size difference with a 70 mm MAF and 80 mm zip tube

Very nice! If I ever end up with a non-P71 this'll help greatly.

Adding search terms as this was hard to find

2004 P-71 PCM swap

$100 MZT

I cleaned up my photobucket account. All the missing pictures can be found here

http://s348.photobucket.com/user/folingo...rt=3&page=1

I will end up captioning the album

Thank you for this thread, with all of this info I was able to swap in a 2004 CVPI computer with 80mm MAF and tube in my GM. Everything seems to be running great, even with the 2.73 gears it shifts very well.

For reference the car I got the computer from was an 08/03 build date and HWT2 code.

GREAT!!!

I finally have a convert!!

I did steal your idea and used connectors to be able to swap MAF cables which worked out quite well I think.

Here's a few pics, I'll upload more of the finished product later.

Pics

Confirmed... 2007 Crown Vic Sport (has 80mm from CVPI) , i installed a 2007 CVPI computer and grounded the 85 pin on the starter relay and viola...it started and runs like a beast!!!!!!!!!!!!

GREAT!!!

Now I will add the 2005-2007 (probably up to 2011) will work with the $100 MZT!!!

Bump for working pics? I would like to see how this is done. Thanks

http://s348.photobucket.com/user/folingo...rt=3&page=1

Alex.

I wish I could fix the thread pictures,

NOW I CAN since I have Moderator Superpowers!!!!!

the photobucket album pictures are now captioned (you have to start with the picture of my wife holding the air filters) so you can follow along!!

Pukebucket is total failure

Here is the album, I have to download all the pics again as they are scattered among the stars

http://s348.photobucket.com/user/folingo...rt=6&page=1

I did this to my 2003 because it was cheaper than replacing the shot civilian PCM.
The 2003 PI PCM cant use an 80mm MAF without a program adjustment right?