The E4OD has an on/off solenoid to control the torque converter clutch. A switch is all that is required, there is no control. Either the solenoid is powered or not powered. The EPC is the only solenoid in an E4OD that requires a controller.

Just as an FYI, the torque converter clutch solenoid in a 4R100 is a pulse width modulated (PWM) solenoid that requires a duty cycle controller.

 

This is an E4OD, but I can do PWM easily.

I am confused. Baumann gives 9 different TCC Firmness levels (0 to 255)based on the TPS value. I can only control On/Off with a switch.

Maybe that applies to the 4R100 only. I am using a Ford Lightning model. I'll look at another model.

 

You would be able to do that with a 4R100, not an E4OD.

If you switch to a PWM solenoid you also need to open an orifice in the trans. I think it is in the pump body, but I'm not sure. The E4OD has a small orifice, in the 0.030" range. When the solenoid switches from off to on, this orifice controls the apply time of the lockup clutch. A PWM system has this orifice wide open (at least 0.250") so that the PWM controls the apply time.

 

Does EPC Pressure have anything to do with the TCC Firmness? The Baumann TCC curve seems to be a reciprocle of the EPC curve.

 

Only to a small degree. The torque converter is limited to 120 PSI, so any line pressure above that won't affect the converter.

 

I'm going to continue on the path that I'm on for TCC. I can switch to PWM, if necessary.

I found the Temperature Sensor Transfer Function. I should be able to find the Fluid Temperature Pressure Adder.

 

One more question.

When is the EPC current set? In Drive only? In all gears? In Park & Neutral is it Zero?

 

EPC must be controlled in all gears. EPC controls line pressure, which is used to maintain capacity in every clutch. If the line pressure is too low clutches will slip and that's the end of the trans. It can be zero in park and neutral.

 

Mark,

I set the TCC lockup to 45 MPH in 4th, and the same in 3rd, but the motor will be turning faster in 3rd.

When is the CCS energized?

 

The CCS is energized when the OD OFF light is on. It applies the coast clutch which is used to provide engine braking in 1, 2, and 3 when the OD is turned off.

It can NEVER be energized when the trans is in fourth gear or you have what's called a tie up. A tie up is when all parts of the rotating assembly are held from rotating. The output shaft stops RIGHT NOW and the rear wheels also stop. Either that or hard parts break.

 

Mark,
Thanks! I'll have to make sure that the Coast Clutch in disengaged, when OD is turned on, and also whenever the trans shifts into 4th gear.

 

Mark,

I don't have the OD Cancel switch implemented on either vehicle. I can't turn OD off. I assume that I will never have to energize the Coast Clutch Solenoid as long as I don't cancel OD. I could implement it in the future, but I don't use either truck for heavy towing, so I have no need for it.

 

Yes, that's true. If you move the shift handle to 2 or 1 the coast clutch is applied hydraulically, it doesn't matter if the CCS is energized or not.

 

I have had a small delay. I have the software done, but I planned to Wire Wrap the jumpers on the circuit board. I bought an electric Wire Wrap gun, but it came without the specific bit that I need. I have that on order, and should get it this week. If all goes well I could be testing it this weekend.

 

The tools that I needed finally showed up on Saturday.
I used to be proficient at wire wrapping, but much time has passed, and my eyes are not what they used to be. I got 2 jumpers wrapped in the first hour, and 4 more in the second hour. In spite of my difficulties, I was able to get all of the jumpers installed.

Now I need to add a connector, and mount all of the parts in a box, including a MOSFET for the EPC driver, and a DC-to-DC Power Converter to power the unit from a 12 Volt source.