I have been reading this forum for six weeks now and have read many posts. I have come across several solutions to problems with my '92 to no avail. It was sitting up for a couple of years before I bought it. Any and all help would be appreciated. Here goes:
Irregular hard shifting between 1st and 2nd & 2nd and 3rd
engine dying while driving (especially during a turn)
hunting for O/D
cruise doesn't work
have gotten the following codes regularly:
625, 631, 565
sometimes:
328, 512, blinking O/D light on shifter
I have replaced the TPS and rear end sensor.

I have gotten many "maybe this" ideas. I am leaning toward a problem in the steering wheel and/or a solenoid failure in the tranny. I do think it is more than one problem which makes diagnosis more difficult by tenfold. Hopefully someone recognizes these same symptoms and can point me in the right direction. I have poured through my new factory shop manuals for an answer, but I don't turn a wrench for a living so I am twice as dangerous. I will respond to ?'s.

 

Code 625=
electronic pressure xcontrol solenoid- driver problem in electronic control assembly (ECA)

Code 631=
overdrive cancel indicator light- circuit failure

Code 565=
canister purge solenoid-circuit failure

Code 512=
electronic control assembly problem (ECA) Keep alive memory test failure

Code 328=
EGR valve position (EVP) sensor- signal lower than expected
(closed valve position)

Check for all vacuum leaks and broken vacuum lines especially in the area of the canister- you have a leak. Check and clean the EGR valve assembly, might require replacement. And most likely the PCM is going south. If so, NAPA has one that is ready to go for your truck. I think I paid about $200.00 for my 91 Bronco.

 

Thanks Labnerd, I didn't want to list all the code definitions for time's sake. I will check for vacuum problems. I replaced the TPS because it looked as if rodents had gnawed on two of the wires up against the sensor itself. They were exposed and probably touching each other at some point. I probably have more exposed wiring that I can't see. It has been suggested I replace the idle control solenoid. I guess they meant the air bypass valve just above the TPS. I will remove and check for blockage or whatever. Is the PCM the power control module in the tranny?

 

Always post the definition with the code number; several definitions from different sites, if possible. We don't want to go looking them up, either.

625 suggest you're overdue for a rebuild. There were MANY known issues with early E4ODs (about 80 TSBs), and one rebuild will turn it from a turd into one of the strongest & most-durable slushboxes ever offered in a 1/2-ton truck. It's still being used in 1-ton & heavier PowerStrokes (renamed the 4R100). A rebuild is expensive, but you'll probably never have another problem from the trans no matter what you do with the truck.

Since the O/D light was flashing AND you have 631, you probably have broken wires in the shift lever. Read these captions:



The PCM/EEC is the main computer for the engine & trans mounted between the cowl & the e-brake pedal. '87-93s are known to burn up sometimes. It's fairly easy to pull it forward into the engine bay & smell it. If it stinks, replace it. Automotive Terms & Abbreviations



Dying during a turn might be a bad IAC, or steering box, or wiring fault, or EEC... Read these captions:

. . . .

565 says the CANP circuit has problems:



It doesn't indicate a vacuum fault - these early systems don't monitor that anyway. But test the solenoid before replacing it.

 

Thanks Steve, I have an '94 parts truck available that has been rolled. I am considering pulling the tranny and using. Will check the EEC. I found a compatability chart and may try to swap the EEC out if needed. Since the trucks does move, should I consider the selonoid replacement first? Does the solenoid usually get replaced in a re-build?

 

I'm not sure if they replace it or not, but the code isn't for the solenoid itself. It's for the EEC (=ECA=PCM), so I'd look at that first. I'm no slushbox expert, but I get the impression it's burned up because the EPC is operating at too high a duty cycle because of worn clutches or deposits in the trans. Not because there's anything wrong with the EPC.

This may interest you:

 

I replaced the ECM out of '94 with the same 5.8/E4OD set-up as my '92. Drove better than ever before. I couldn't believe it. All the codes, engine dying, and tranny bucking. GONE! Has been about a week and still driving fine. Codes show 111. Tranny shifts so smooth I can't even feel it. I guess the ECM can't tell when IT'S the problem. Bought a replacement tranny from same '94 to have on hand before I changed the ECM in case the tranny was needed. Four hours of labor and $58. I don't mind having it on stand-by if neccessary. Thanks to all responders. I also couldn't help notice when looking at the ECM pin chart that a several of the problem codes I gathered seemed to correlate to the pins nearest the top of the ECM (i.e. how it is mounted on the firewall). Could have been a clue, maybe. There was surface rust on the top of the '92 ECM but it didn't smell "cooked". The '94 ECM had lesser rust markings.

 

Pull the covers off the bad one & upload a few pics of the circuit board & connector face.

 

Will do. Took the covers off. Nothing stands out as abnormal, but what do I know? Could it have been something as simple as cleaning the pins? Never thought that would create so much havoc. I might clean it up and swap it back to test the theory. I have waited to for the other shoe to fall before I permanantly install the newer ECM. Should I use dialectric grease on the pins? Seems like a good idea. I will also put a small amount of silicon sealer around the mounting gasket to stop any further water infiltration.

 

NOE!

Read the bottom of this caption:



Re: your e-mail... (Post all tech questions here in the open forums.)
Your '92 uses the older vacuum cruise & sliding contacts; not the electronic servo I posted about being submerged, or a clock spring. Read this caption:

 

Low current flow switches less than 0.1 amp? Thanks for the thumping.