Hello all,

I got a good deal on a '92 F150, 8 cyl 4WD with an A40D transmission and drove it home. Disclaimer: this is my first truck and I've never done repairs on my own before ( ) but I've helped a buddy work on his now and then.

Now, it drove home fine, but the next day when I tried to take it in to do the registration, the engine would die as soon as I took my foot of the brake in reverse. I checked the codes and it threw a 624, looked it up online and my best educated guess was "EPC solenoid." Took the tranny pan off, a more competent neighbor of mine (cert chevy mechanic for 25 years or so) checked the solenoids, and sure enough the EPC solenoid is fried up real crispy.

So having seen this video ( ), I'm thinking this is a fairly simple fix mechanically speaking, just some more money I'm throwing at this thing. My neighbor the Chevy guy, though, he's looking at it like it's more complicated than he was expecting.

I guess my question is this: is the video right? do I really just need to order a freagin solenoid pack and switch it out like this guy does? Or is there another procedure I need to do here that I'm missing?

(P.S.: tranny pan is back on with a new gasket for the time being just to keep the dust out of the works, I am under adult supervision after all )

Thanks

Eli

 

The Electronic Pressure Control (EPC) Solenoid is a variable force type solenoid that regulates transmission line pressure. With This malfunction you don't even want to run the engine as it could lead to severe transmission damage.

Word of Caution on testing the EPC Solenoid. All other Solenoids are 20-30 ohms. The EPC solenoid is 4.5 - 6.0 ohms. (a lot of people think the EPC is shorted because of this difference). If the EPC solenoid is truly fried it would be 0 ohms (burnt wiring) or very high resistance - partial burnt windings. If the EPC Solenoid is within 4.5 - 6.0 ohms its not fried.

Its very odd that the EPC Solenoid Fried the way it did. Need to check wires for shorting.

Regardless of any other possible issues with your E4OD, you need to replace the Solenoid Pack with a 89-94 unit as they have the Spike Protection Diodes on the Solenoid in 92. Ford moved these diodes to the Powertrain Control Module (PCM) in 1995, so a 95+ solenoid pack won't work on your vehicle.

I would inspect the wiring and harness connector at the Solenoid Valve Body connector to make sure wires are not bare and shorting. This is a common problem as these wires are in close proximity of the exhaust pipe.

It would also be advisable to disconnect the PCM connector and make sure the ECP Solenoid wire is not shorted to ground some how. THe 1992 "F" Series Truck ECP Wire (PCM - to ground wire) is White with a yellow stripe. Its pin 11 on the Solenoid Connector and Pin 38 on the PCM.

All solenoids use a common power feed that also powers the Fuel Pump and EEC relay (Red wire). However, the EPC solenoid has a separate Red wire at the Solenoid Connector. The TCC / Shift 1 / Shift 2 and Coast Clutch solenoids use a common Red wire for their power.

when you have the Solenoid connector disconnected you can check resistance on the pins coming out of the solenoids to the PCB board (where they are soldered). All should be 20-30 ohms expect the ECP should be 4 - 6.5 ohms).

Also, you can set your scale on 100-200 ohms and check the 5 black diodes. One way with leads touching diode should show resistance. Reversing leads on diodes should have "No resistance". These diodes only allow flow one way.


If the EPC is truly fried, I suggest ordering a rebuild one. If the EPC is withing resistance specifications of 4.5 - 6.0 ohms. I would still recommend a Line Pressure test to make sure you have EPC Line Pressure control and if you do -- one last test.

Test drive your trans in LIMP MODE by leaving off the Solenoid Connector (protect if from the exhaust pipe though). In LIMP MODE your E4OD will take out in 2nd and shift directly to Overdrive (4th). Its a way of bypassing all electronics and verify hydraulic / mechanic function is working okay.

let me know if I need to expand on anything.

Let us know what you find out.

 

Almost forgot. Also check out my E4OD Free Tips eBook I developed in 2006; updated last month. It has a lot of diagnostic and shows you internal pics, etc.

http://e4od.com/index.php/2015-01-18-18-51-55

 

Wow, that was super helpful. Looks like my next step is for sure getting a new solenoid pack - I noticed they have a '94-'98 pack and then an '89 - '93 pack, so definitely will be making super sure I get the right model. REALLY GOOD TO KNOW about the rebuild packs, like I said I am a total newb at this so I was pretty concerned about new vs. used where that was concerned. Thanks very much.

The solenoid came up at .03 ohms, so I will make sure to do a real thorough check of the wiring for any issues when I take it out for replacement. Overall, the wiring is in really good condition, but I may well have missed something and I don't think I can really spend too much time getting to know the electronics on this thing anyway.

Thanks again! I will update when I get the part and start fussing around with the insides some more. Don't anybody worry about me trying to run anything until I get the new solenoid and new filter + fluid back in the tranny - like I said, I'm under adult supervision here!

 

All 89-94 Solenoid packs have the diodes on the Solenoid pcb board and will work but, there is a Gas version and Diesel version of these Solenoid Valve Bodies. You need the correct version for your engine type, gas or diesel.

 

Yep, ordered the replacement pack last night and made sure to get one made for a gas truck. Will let you all know how it goes when I replace it!

 

Update: put the new solenoid in, replaced the tranny fluid and filter and my truck's running in all its gears now! Shifting smooth and everything.

Thanks so much for all the help!

 

SuperDuty Cool that you diagnosed it correctly and fixed it yourself !


If I may ask, What was your total cost to do your own repair ?

I'm building an estimate page for repairs and how much people can save if they repair their own E4OD.

Bobby

 

Bobby,

The new solenoid pack ran me $250 with shipping from rockauto.com, and then I think new tranny fluid wound up somewhere between $30 and $40. The new filter kit was $25 (I think, I wound up buying and returning a couple of the wrong size), and then I borrowed the tools from my neighbor so overall cost was about $310. I'd estimate maybe 3-4 hours of labor overall, and that includes trips to the parts store and scratching my head staring at my engine and watching tutorials on youtube.

 

Hi Eli92,

Thanks for the info on cost and repari time. As far as skill set, do you think the skills needed to replace Solenoid Pack are ?:

Anyone can do it alone if they can do a tune up and watch youtube video.

or

More advance and most people will need to seek out help form experienced mechanic.

Thanks,

Bobby