94 exp pcm question | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

94 exp pcm question


New Member
December 11, 2011
Reaction score
City, State
tulsa, ok
Year, Model & Trim Level
94 explorer
I'm needing to replace the pcm/ ecu in my explorer. Problem being the morons at the parts house can't seem to find my exact unit. my pcm is a F47F-12A650-Mb . What i'm wondering is if any other pcm from a 94 will work or if it HAS to be THAT one. It's a 94 exp 4x4 auto truck.

any input would be great.


looking for pcm F47F-12A650-Mb

Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!

Try searching ECM on rock auto under '94 Explorer.

Did you give the part number off of the original one? Overly simplified there would be 6 possible replacements-federal emission automatic trans,federal emission manual, California emission auto and manual, and high altitude for auto and manual.I realize there different emission calibrations in each,but that would get you close. You could also look for a good used one on this forum.

Basically your truck being a 94 has Calif emmisions, all 94s did and most 93s had it. Look for a 93 with an EGR system or any 94 with the same trans option. I assume yours is an auto. Try your local junkyard, I think they get about $35 for modules of any kind at the yard I go to.

Just curious, but what is wrong with your original one?

my pcm is number F47F-12A650-Mb .

92exp4x4 good info. thanks. Yes mine is auto.
Whats wrong with it is this... it decides when it wants to run right and not. Sometimes it will run and idle fine and i get about 14mpg out of it then. Other times it decides it wants to run stupid rich and doesn't want to idle for anything. Idles like it has a HUGE cam. When it does that I get between 8-12mpg depending on what it's feelin. lol.

I've replaced the tps, egr, all vacuum lines, mas, plugs, and wires. I get a code pcm to ground. all grounds seem to be good. I clear the code. When it runs right I don't get the code, but as soon as it decides it wants to run badly then I get the code (which doesn't take long. I never get a full tank out of it when running well).

There is a dedicated PCM ground at the battery. also, a bad body ground or engine to firewall ground can also give the PCM fits.Try checking all of those.

So for one....my ground at the battery was horribly corroded! The thing is I cleaned that very well and it still has rough moments. It is much better, but is still not right by any stretch!

You may need to just replace the battery cables- the battery acid wicks its way inside the cable, and corrodes it, and increases the resistance.

Ok so It was warm today and I did a little troubleshooting. I found that both my battery cables were loose. I cleaned and tightened them. I found that there was no apparent corrosion in the cables inside the insulator. None of these things seem to have made any difference!

I also found that there is a plug I cannot seem to identify... It is a round black plug with a black and a black/white wire going in to it. What are those wires? Because on the other side of the plug someone has got both of those wired to a ground block that wires to the battery and to the body ground near the battery.

Please help! This averaging 10 mpg bs is killing me!