Hello all, I have viewed these forums for guidance along my swap. I am a GM tech not too familiar with ford programming. The crazy stuff we do for the girl.

Situation: The truck is a 98 F150 4WD with electronic overdrive on/off located on the sifter. Originally the truck came with a 4.6 in it. In the life of the truck -roughly 146,000mi- the engine was rebuilt by somebody before i was introduced to the beauty. Since the "rebuild" both head gaskets are gone, multi cylinder misfires, intake leaking, rings shot, 0 compression at all, rod and spark knocks, and much much more. The end result was to rebuild this engine for a ridiculous amount of time and money myself or find a donor. I found a donor 97 5.4 f150 with 2WD.

Removed 97 5.4 engine from donor and removed ALL electrical from firewall up. Removed 5.4 PCM as well. Cleaned and touched up 5.4 engine. All electrical still in tact no problems. Then I removed her 98 4.6 from her truck and tossed it in the bed of my Silverado. Then installed my 5.4 donor engine into my girlfriends truck. Installed all electrical from firewall forward onto her truck that i removed from the donor. Installed engine and torqued. Some minor conversions were necessary but nothing which would result in my current problem.

So, now I have a 98 f150 with a installed 5.4 to replace the 4.6 . I plug in my 5.4 PCM/TCM -they are in same module box and cant be isolated from each other. Crank engine over and she fires right up and idles like a dream. Revving it in the driveway and i have no issues at all, Engine is running great with no concerns at all. This is where the problem comes.

Put her truck in reverse and back up, i feel a rough engagement and minor slipping felt while pulling out. Throw it in drive and i feel minor slipping in the transmission but the truck moves under her own power. Once top end of 1st gear is met the TCM will attempt to go into second gear but will end up slipping and revving up to about 3000RPM and finally catching into second. The trans will run through 2nd gear and then try shifting to 3rd, At that point more slipping is felt and finally a rough engagement into 3rd. The truck will run through 3rd gear but will NOT shift out of 3rd. Again, this is running my 5.4 PCM/TCM from 1997 in the 98 trans/truck.

Digging around on your forums I find information stating that in 98 ford released a new transmission and a 97 TCM will not be compatible with or know how to operate the 98 trans. -again 98 trans is 4WD, 97 was 2WD-. I expected to have some transmission concerns after doing the swap. Just to clear the air, the 98 did NOT have 1 single transmission concern prior to performing the swap.

If your still with me my question(s) is this-- Can I put her 98 4.6 4wd pcm/tcm back in her truck and find programming to set the pcm to run 5.4 settings? My fear is that I won't be able to override the VIN stored in the 4.6pcm.. If i have a vin code of a 98 f150 with a 5.4 and the same transmission would i need to program that vin to this module? Is it even possible to program over 4.6 settings? Did i just waste a week of work after actual work to bust this out?

I ran up to a salvage yard u pull lot and found only 1 truck there that i though would be a match. I found a 98 or 99 f150 with a 5.4 in it and what appeared to be the same transmission from the little i could actually see.. I grabbed the pcm/tcm box from it and ran back home to plug it into my girlfriends truck. Truck started and idled fine/no engine concerns yet again. but exact same transmission concern. My only option i know is to try to program this 4.6 pcm to match 5.4 settings. my 5.4 is still coil overs and is not the 4.6 plug and wire setup.

While driving i can shut off overdrive and throw the trans in manual first gear, no slipping felt, then throw it in manual 2nd and feel no slips, throw it in manual drive with o/d shut off and find no problems. but no o/d or "4th" gear...

If I need to provide any more info or vin codes or anything please help, Im hoping to have it running in a day or two...

Thanks to all input!

 

The 99+ F150s had PATS key that has to match PCM. There will be issues if you try to swap that in.

 

It ran with the 98 or 99 pcm I got from the yard, hell it's idling right now. Just the same trans issue

 

Would be a 98 then. If it was a 99 it would not start without the right PATS key.

Did the donor have the same transmission? One of them might have a 4R100 instead of a 4R70W. A quick and easy way to tell is the VIN tag on the driver's door jamb.

 

Yes, the trans was different as I stated in the first post.

 

That is most likely your problem then. Probably the cheapest & easiest fix for you at this point is to find a 1998 5.4 PCM from a truck with the same transmission that you already have. There is a chart on here somewhere that has all the info on how to decode the door jamb sticker to be sure you get the right engine/transmission combo this time.

 

thank you, ill have to try to find a matching door jam code. I was assuming my options were to grab a 98 5.4 with the same trans or attempt to program then 4.6 to 5.4 because its got the trans stored in the tcm. Ill have to find that chart because today I thought i found a matching pcm but still had a trans slipping issue. door jam code is "u"

 

U is 4R70W
How To: Decode VIN Number and Vehicle Sticker - F150online Forums

 

So if I find a 98 f150 with a 5.4 in it and door trans code -u- I should be able to plug and go. The hunt begins