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What I've learned about the E4OD

89527 Views 80 Replies 16 Participants Last post by  pat.joyner93
First the acronyms:
  • TECA, PCM, TCM: these all refer to the computer. TECA is transmission electronic control assembly, PCM is powertrain control module, and TCM is transmission control module.
  • TECA relay: Referred to as the EEC relay by most autoparts stores, it switches power to the TECA and sensors when the key is on
  • VSS sensor: Vehicle speed sensor. 91 and older it's located on the trans tailshaft with a cable going through it to run the mechanical speedo. 92 and up use the rear ABS sensor, sometimes referred to as the VSS sensor at autoparts stores
  • FIPL: fuel injection pump lever sensor, also referred to as the TPS (throttle position sensor) by autoparts stores. It tells the computer how much the throttle input is
  • MLPS: manual lever position sensor. It's also referred to as the TRS (transmission range sensor) and it tells the computer what gear is manually selected (PRND21)
  • Tach sensor: located on the timing gear cover, indicates engine speed to the computer
  • TFT: transmission fluid temperature sensor, it's part of the solenoid pack
  • SS1: shift solenoid one
  • SS2: shift solenoid two
  • TCC: torque converter lockup clutch
  • CCS: coast clutch solenoid, controls the coast clutch to allow some engine braking on deceleration *See MLSC's post below*
  • BPS: barometric pressure sensor, indicates altitude to the computer
  • EPC: electronic pressure control solenoid, located in the solenoid pack, controls shift firmness.
  • PSOM: programmable speedometer/odometer module. On 92 and up it converts the rear ABS signal into a VSS signal for the trans. It's also the speedometer as it is attached to the rear of the speedo gauge.
The most handy piece of equipment to have is an old style Ford EEC-IV code reader, or an newer code reader that can hookup to the old style EEC-IV diagnostic terminals. Codes can also be read with a test light or a multimeter. If your trans is acting funny the first thing to do is get the codes! The second thing to do is remove and replace the connectors on the trans, clean off any corrosion. The problem could be as simple as a bad connection. If there is no automatic control then either the trans isn't getting power, the sensors aren't grounded at the pass. side battery, or the solenoid pack is burnt. In my case metal sendiment from miles of trans issues settled on the solenoid pack circuit board and shorted it out. It doesn't hurt to pull the pan not only to check condition of the fluid but to do a fluid and filter change. If you do it wouldn't hurt to unbolt and remove the solenoid pack and give it and it's connector a good cleaning.

Now just throwing sensors at the problem can get expensive so again it's best to get the codes. 92 and up used an upgraded MLPS and the connector is different, most parts stores will sell it with a pigtail connector or a new connector body that the terminals from your old connector snap into. If this is bad all sorts of things can happen, no OD, no converter lockup, dropping in and out of lockup or gear, etc.

There are posts all over this board about the FIPL, make sure you have the newer grey style. IIRC it should be 1.1 ohms in the closed position and no more than 4.5 ohms at WOT. This is meaured by sticking a probe on the middle wire and the other to ground, then manually move the throttle from idle to full slowly looking not only for min/max but also bad spots in the range.

The VSS signal tells the trans when to shift as well as lockup the converter. If it's bad or open the converter may not lockup and the trans takes forever to upshift, almost like it's slipping. I believe a bad tach signal can do the same thing.

If your trans is shot try to get one appropriate for your year. I bought a 94 trans to go into my 91 van and found that there is not a gear machined into the tailshaft for the VSS and cable speedo drive. I was able to get around this by rigging up a PSOM from an 93 van and outputting it's VSS signal into the original trans harness. I had to completely remove the trans harness and install the updated connectors for the solenoid pack as well as the MLPS. The end result however is a trans that shifts really nicely. I also have a 99 4R100 trans with a driveline parking brake, my brother confirmed it has the gear for a cable driven speedo in the brake housing. It was also confirmed elsewhere on this forum that that trans is the same as a 4x4 trans if you remove the driveline brake and install a transfer case. I believe that most transfer cases have the provision for the cable speedo drive.

My future plans include hooking up a manual TCC switch that will give me locked, unlocked, and normal. I'll post more on that later. I also plan on a large trans cooler with an electric fan and a trans temp gauge as I often do heavy hauling. Eventually I'd like to rebuild the 99 4R100 if it is confirmed it will fit this van and do a 4x4 conversion. Especially since I've got a front Dana 60 waiting for me to pick up. I'd also like a torque converter setup for towing and the appropriate shift kit.

If you are experiencing harsh shifting, funny shifting or no shifting, please check the codes and the appropriate sensors and connections first. Don't let it go unfixed. I am certain letting it go destroyed my original transmission.

I hope this thread helps as many people as possible. I am no expert but i have learned a lot in the past few weeks from trial and error, the forum, and wiring diagrams from the library. I have also learned that the E4OD is one heck of a stout trans and should live a long time if everything that supports it is kept properly maintained. I admit I was very frustrated with it at first, seemed like a lot of complexity for an extra gear and a locking torque converter but once you understand how it works it's rather simple really.
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I am no expert
...but you sure packed a lot of excellent information in that post! :thup:
The coast clutch is also applied by the PCM when the trans goes into OD.
The coast clutch is NOT applied in overdrive. If it were on there would be a tie up, which is when all parts of the planetary gearset are held to the case. That means that the output shaft would immediately stop turning, which means the wheels would stop turning. There is engine braking in overdrive without the coast clutch applied.
The coast clutch should come on when OD is turned off. If OD is not turned off the coast clutch will not turn on. When the coast clutch is on the engine will not go to idle speed. Yours is not working normally.
A bad PCM is always a possibility, but very rare. PCMs do not fail often.

Most likely your coast clutch is not working. Does it have engine braking when the shifter is in 1 or 2?
The coast clutch solenoid is not on in overdrive. If it were the output shaft would not turn and the truck would lock the rear wheels. If you keep having the same problem with multiple transmissions it is likely that the transmission is not the problem, something outside the trans is wrong.
There is no way the mechanicals inside the transmission will let the engine go to idle when in fourth gear. In third gear with the OD enabled it does that by design. It should not go to idle in third gear with the OD OFF light turned on.
The shift schedules are adjusted for altitude. The shifts will happen at lower RPM for a given pedal position.
Often a lockup problem is electrical. A burned out brake light can cause this, either side OR the center brake light on the rear of the cab. Just replacing parts without any diagnosis gets very frustrating, not to mention expensive.
If the OD clutch and the coast clutch are on you'll have a tie up. That's where the output shaft can't turn and the truck won't move. If one of them is dragging, but not fully applied it could do what you're seeing. That will cause extreme wear on the dragging clutch.
I've never seen this condition happen, but it could be the coast and od clutches.
In theory , all e4od and 4r100 will do this in limp , correct?
No. There shouldn't be drag in manual 1 in limp mode or not.
In man 1 , are the od clutches bypassed hydraulically?
Yes it is.
Mark while we are on this clutch deal, I have a question. I have noticed after sitting for weeks these trucks make a sound when coasting at speeds under say 40 mph, that sounds like the coast clutch releasing and engaging back and forth. You can hear it by the way it effects the engine.
They seems to clear after driving for awhile and does not return till they sit for weeks. I noticed this on a fleet that gets rotated to and fro a separate location and lot.
I've never heard that, and have no idea what would cause it.

Great so there must be a problem with my rebuild. Maybe a backwards roller clutch?
If either roller clutch were backwards you'd have a lot worse symptoms than this. My guess is that there is a leak between the coast clutch and the overdrive clutch.

One way to determine that would be with all solenoids connected, push the OD OFF button. If it has the problem in in any gear, then that's what's happening.
I suspect the leak is from the coast clutch to the overdrive clutch. It would only leak when the coast clutch is pressurized, and that's in M1 and M2, plus 1, 2, and 3 with the OD OFF.
You can't do the test I outlined above without a controller.

I just remembered something that's relevant from way back in my memory. The forward clutch drum can't handle max pressure for very long before it blows apart. Running with no controller in M1 puts max pressure in the forward drum. Either stop doing this or expect your trans to blow apart soon.
The controller isn't commanding enough line pressure for reverse. Is this a Ford controller or an aftermarket?
What trans was in it before? Is this computer from the old trans?
The 4R100 computer isn't going to work with an E4OD. It need both turbine speed and output speed sensors or it is going to be in limp mode all the time.
The TPS does have an input for pressure in reverse.
EPC in reverse is controlled by engine RPM and TPS. The '94 will use VSS for shifting, there was no OSS on a '94.
Can I use the vss signal from the rear end of the 01 truck for a vss?
That should work.
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