Migrating a known good pcm/pats/key to a similar vehicle

[corerftech]

I have a 2001 exp.
I have found a local privateer dealer (auction flipper) who resells and locked up a good Mountaineer. Has a clean title, I’d like to avoid towing.

A thought-
Same car, engine, etc. First year pats.
Could I use my 01 PCM (no longer in service) and my PATS module (also no longer in service) with my good keys that are programmed to get that car started?

Of course my PCM has had no juice for nearly a year. The pats a similar period of time. Left over parts from my carburetor/uSquirt conversion.

I can probably have forscan extended lic on hand if it will assist any. I still have two good keys. Not worried about fitting the ignition. I can get a blank RFID key cut to match the tumbler and add with forscan.

Just thinking out of the box or maybe not so far out of the box. Will cost me a $100 for a tow and I’ll still have the same problem when it lands at my door.
Appreciate in advance your replies.

 

[Brain75]

you didn't tell us the year of your mountaineer candidate.... and 2001/2002 they changed from system B to system E

As long as the recipient doesn't have it integrated in to the cluster I would think your plan would work... if it is past the detachable module and more integrated then more headache.

 

[JoshT]

I seem to recall @corerftech converting his 2001 Explorer 5.0L V8 to carburetor, so I would assume that the Mountaineer is also 5.0L V8. To my knowledge they did not build any 2002 Explorers/Mountaineers with the 5.0L V8. 2001 was the last year for that, so they never got the E type PATS.

PATS aside, I think this would only have a real chance of working if the Mountaineer is a 99-01, and best likelyhood if it is a 2001. Ford liked to make running changes in the wiring harnesses. I don't think that there were any major changes for those three years. Earlier models, would likely have too many differences to work right.

Are you certain that the issue is a bad PCM?

I don't think the time unpowered is going to be any issue. PATS equipped vehicles have sat for longer periods with no power and fired up and ran once a batter was installed.

If you have the key available, I don't think it's difficult to pull the ignition tumbler. Might take the whole key sylinder and put it in the Mountaineer if you can afford for your explorer to be down that long. Would allow time to get a key cut and programmed, or new tumbler and key for the Mountaineer. Sometimes it will work if the transponder key is just held close to the ring when starting, and not actually in it, but might not work if there is also a different transponder key in the ignition.

If you have the transponder ring from the Explorer, ytou could tape it and a key together and plug that ring in place of the Mountainner's ring. Then it would think that the transponder key was the one inserted. That's basically what they used to do for remote start systems.

If they have the keys for the Mountaineer and you have FORScan, you shouldn't need to get a blank key, just program the mountaineers key into your ECU. For that matter maybe they just screwed up the programming for the existing PCM and the existing key just needs to be reprogrammed to it?

 

[corerftech]

JoshT nice pull on the car!

yea- 2001 5.0 2wd explorer is the donor for electronics.

98 Mountaineer would be the recipient.

The only real use I would get from it is:

A- not have to pay for a tow/wrecker delivery

B- be able to test fire the engine and test shift trans under power

Being the hack that I am, intended purpose for car is to give it a 4wd T-case which I received as a donation a couple of weeks ago. And it would get a distributor and carburetor with another TCU. I think the 98 has only 200k on it (only- LOL) and is in arguably better cosmetic and historical condition than my pillow of crap 01…. Which I am quite fond of now. It’s a peg leg car. For snow and ice, would love to have a 4wd version. The 98 is a perfect recipient.

I have a feeling that it was a theft car (legit on this end) and an insurance auction. Sold with one key- I got that from the seller. I found out they threw a fuel pump
And relays and suck at it to get fuel moving in ignorance- potentially dead pcm, or as I think they have figured out- immobilized. I would buy it if I could light the fire on the engine and hear it.

Hell I might just pour fuel down its throat and send it. Still have to tow but if I can get it to rattle enough to see oil pressure and not hear a rod knock- that would likely be enough to mitigate high risk.

Does the rfid key head have to be precisely in the antenna ring or if the tag is in close proximity, might it be read?
It’s a great system and apparently is working well in this case!

Thanks for the input folks. A squirt bottle of gas may be just as promising. Not driveable but potentially provide an adequate test.

 

[corerftech]

And JoshT just re-read your whole reply.
Yes- you have given some hope and answered my secondary questions. Sorry bout the oversight. Great idea on the antenna swap!.

I think as least forscan is worth a shot. An interface arrives tomorrow (hope it the right one) and I’ll have the software. As well I like the idea of the antenna in parallel. Use my antenna wired to harness with key in place, use mechanical key that fits car in tumbler. Use my PCM and pats- if all else fails. If the seller will allow such nonsense!

Does the antenna remove easily on my donor 01? Or am I digging into the harness to the headlamps to get it out? I may be making a headache at a level that modern medicine can’t relieve! I have not had to touch one to date.

 

[JoshT]

I have a feeling that this idea is already moving past what is practical to avoid a $100 tow bill, or what the seller will likely allow. I don't think that your PCM will work on a 98, at lest not P-N-P, due to a few differences in wiring and sensors. A few that I can think of off hand are:

1) MAF and IAT sensors are different. IIRC the 98 uses a 4 pin MAF with the IAT located in the intake tube. 99-01 use a 6 pin MAF with the IAT built in. The harness wiring isn't majorly different betweren the two styles because it is a simple job to rewire for the swap, but they may use different programming. To be safe you would need to rewire and swap in the MAF that matches the PCM. That said, I canm;t say that the 98 MAF andIAT wouldn;t work with the later PCM.

2) This one is the major killer for the came swap idea. Different cam position sensors. Some 5.0L Explorers use a 2 wire sensor and some usse a 3 wire sensor, and the two are not interchangeable. Even the entire cam synchronizer base is different. The transition year was 99 IIRC. The 98 is most likely going to have the wrong style for your 2001 PCM, and I'm not sure that there is any way around that short of replacing the entire synchronizer and harness to match the PCM. I'm not sure if the truck would even try to fire without the Cam PS connected.

3) Different fuel system. This one might be an non issue. The 98 uses a return style fuel system with 19lb fuel injectors running at 45 PSI. The 2001 uses a returnless fuel system with smaller injectors running around 65 PSI. Generally the MAF, Injectors, and PCM all ahve to be programmed to work together, and you can;t change MAF or Injector sizing without editing the tune on the PCM. Having said that, I've been told that one can convert 98 to returnless with the latermodel rail and injectors andit will run just fine. This is allegedly because the smaller 99+ injectors run a 65 PSI flow the same amount of fuel as the 19lb injectors at 45 PSI. The math I've done on injector sizing in the past seems to support this idea.



The PATS "antenna" is located in the steering column. It's a small ring around where the key is inserted. Pictures in these links might help with what I'm suggesting there. Particularly what RonD said about it in the his first reply to this first link. If you look at the pictures in these, the antenna is the black box with the plastic hoop or ring extending off of it. This second link also had good information about repairing PATS if that is the cause of the problem with the stock PCM. FORScan can go a long way in troubleshooting and repairing these issues.

https://www.therangerstation.com/forums/index.php?threads/need-pats-help-on-93-ranger-swap.173002/

https://www.therangerstation.com/te...ord-pats-passive-anti-theft-system/#gsc.tab=0

 

[JoshT]

Hell I might just pour fuel down its throat and send it. Still have to tow but if I can get it to rattle enough to see oil pressure and not hear a rod knock- that would likely be enough to mitigate high risk.

Thanks for the input folks. A squirt bottle of gas may be just as promising. Not driveable but potentially provide an adequate test.

These or starting fluid might be your best options at this point to verify that it will run. This version of PATS does not disable ignition or starter on a Ranger/Explorer, just the fuel pump and injectors. If it is a pats issue it should run if you can provide the fuel.

These didn't really have an immobilizer that I'm aware, just the PCM cutting the fuel pump and injector. I'm also be surprised it it is a truly deal PCM. More likely the original key disappeared in the theft and the replacement doesn't work, or the theives/tweakers hacked up something vital to operation.



If you were anywhere near me I'd let you borrow a 98 PCM to try out. I know that I have one here somewhere, but I probably can't put my hands on it in time and you're a little too far away for me to get it to you if I did. You'd still have to reprogram the keys with FORScan, but it was working when removed years ago.

 

[corerftech]

With the litany of defects in the idea, it will be best to just try forscan and some gas!

Agreed- too much- $100 tow looks very tantalizing!

Appreciate you precisely walking through that bit.

I’ll see it tonight after work and maybe it’s a pile of crap. The book cover may be much better than the contents, but hope not.

 

[corerftech]

Well I went out and saw the cat first hand. Oh poop! What a toilet.
First thing I looked at was the tires, newish. Next interior through windows- oMg. Popped hood, said huh, new water pump, battery, Tstat. Opened the rad, I see the bottom and some brown crap- hmmmm.
Opened coolant res- it’s full almost to top with fresh.
Pull dipstick- where am I supposed to see oil? On the dip stick?

put hood down, looked at IC.
269,xxx miles. That’s kinda of 200,000 right?

Another Memphis fiasco. Seller said make me an offer I need it gone——
He was 1000 obo. I wouldn’t spend 500 including a tow/trailer rent as I’d get herpes from the interior.

I always wanted a good running 302 that operates with no oil. Very cheap to maintain, right?