Could you have an output for an electronic cruise Rostra cruise control module? That would be sweet!!!!!!!!

Yes, it would be great to have an option to keep the transmission out of overdrive if one was towing something. Keeps the fluid a LOT cooler, even with a cooler. If you are going to have this option button to keep the OD off, then it would be great to have an indicator for this as well that an LED could light up on the dash letting one know they are in OD off mode (or towing mode).

If I had a FAST EFI setup on my engine, would I need anything special to use this controller for the transmission?

Yes, I am very glad you're taking this up -- mark me down for two controllers...........

Mark

Ok, some updates.

You won't need a PC to tune it anymore. I found a handheld screen with buttons I can use for that. When it's not used for tuning, it can either be unplugged and tucked away, or it can show the current transmission variables. I'll have an option to use a PC to update the firmware, but that shouldn't be an issue for most people.


Does anybody know what the pulses per mile for the stock output shaft sensor on the 46RE is? I saw a reference to 4000ppm, but would like to verify that.


Tow/Haul mode: Can anyone say with authority what this button does? I've seen references online that all this does is disable overdrive. I've also seen that it raises the shift points a bit (likely by having a lower governor pressure).

I also saw something that the computer did the same thing in 4-LO as it does with the Tow/Haul mode?

There are differences in Tow/Haul depending on model year.
I would have to go back and see but if memory serves me - one year T/H disabled OD and then later T/H would change the shift schedule to allow OD if certain vehicle parameters were met like vehicle speed versus engine speed.

Also - pulses per mile - i would have to check on that too - 44000 come to mind but it has been years since I worked the logic side of these things. Count the annulus lugs in the overdrive - the part that the park pawl engages (same lugs that the speed sensor senses) and then multiply that time revolutions per mile based on a given prop shaft speed. Also, the 727 and all Chrysler Rear Wheel Drive units operate ALL the same in regards to 1-2, 2-3 and 3-2 and 2-1 shifts. The fight between governor pressure and throttle pressure determines what happens. You can get a 3-2 down shift if you have steady state throttle while the vehicle starts to slow (slowing reduces gov. pressure). Normally closed throttle downshifts result in a 3-1 - yes, but it is not "designed" this way. A sticky throttle valve in the valve body can/will result in a 3-2, 2-1 dhown shift. Lockup on all the old RWD units are controlled by electronics except the very early units. With a lock up solenoid - the solenoid closes, pressure builds behind the LU valve and shuttles it over to acheive LU. When we command no LU, we shut this solenoid off and you get open converter control - no LU.

Just ordered the first version of the circuit boards.

Sometime in the near future I'll be borrowing my parents 93 Grand cherokee to do some testing on. I'm thinking I'll be able to plug in my harness, let it idle, and manually run the governor pressure up and down. If I can do that, then the rest is just programming

Transman:
I've seen controllers engage the Lockup clutch with a PWM over ~1 second to avoid a jerky/clunky engagement. Did dodge ever do that, and/or should I look into doing it?

Any chance of incorporating a specific output out of this controller to only operate an electronic cruise control? 8000 pulses per mile would be ideal for the output from the transmission controller if this can be done.

Again, it's awesome you're getting after this one........

Yes, it will have a 0 to 12v square wave output for speed. I did email the rostra folks to ask if a square wave will work with their system, but never heard back... maybe you'd have better luck than I did if you ask.

I have one of their Rostra electronic cruise control setups and I looked in the installation book to see what their setup can read. There are multiple setups that the Rostra can read, but this one seemed like the most widely used one out there for the OEM's (i.e. 8000 pulses per mile), so I just picked that one. Also, the Rostra electronic cruise can read sine or square wave signals, there is a dip switch on the box for that as well -- so it's all good.

It would be great if you could incorporate an output specifically for the cruise, and another separate output for an electronic speedometer too. Would make it really easy for those of us that are electronics challenged........

I believe we simply ground the solenoid field and then the solenoid closes the valve which then causes the lockup valve to move over. We call that ballistic converter apply as opposed to modulated converter apply.

We did that for everything in the old days.

In the old days - all electrically controlled lockup units - made no difference what model year or trans. That all changed when we went to 41TE (604). Many people are confused what electronics do on the old units, I think because we use different names like PTU (part throttle unlock) etc. The bottom line is we turn the lockup solenoid on or off to control lockup - but all it is at the end of the day - a solenoid opening or closing which makes the lockup valve or solenoid switch valve move. The valve has to move to get or shut off lockup. If the valve is stuck off - actuating the solenoid will accomplish nothing. OBDII will set the check engine light because the controls do not see engine speed reduction after the solenoid is activated.

The only duty cycle solenoids on Mopar transmissions that I am aware of now is the 41TE (604 family), RFE Family, 62TE, NAG1 and now the 8 and 9 speeds. For both lockup and shift control. As for using a PWM to control lockup, the converter and valve body were designed for an on/off solenoid. Again, the converter does not get "turned on" until that lockup valve moves over. A PWM solenoid will accomplish nothing to smooth the converter engagement as that valve moves very little to achieve L/U. plus the damper assembly within the converter was designed to cushion the lockup apply. By dragging the lockup disc too long you put more heat in to the disc. It wasn't designed to be slipped for cushioning.

I was just reading something else that these RE transmissions might do, but I'm not sure -- I'm no transmission specialist by any stretch of the imagination, but this seems plausible so I'll let her rip:

If the transmission goes above a certain temperature, then the OD feature will not be able to engage (this would be controlled by the transmission controller logic). Would this also be the case for the LU torque converter? At any rate, if there is a temperature sensor on these transmissions, or one could be installed, this would be great logic to include with the controller as well. Would it also be possible to have a separate output from the controller to a transmission temperature gauge? I think that is a rather great thing if this could also be incorporated into this logic.

How's it going with the programming of this controller? Any idea when these might be available for operating a 46RE transmission?

Yes, there is a temperature sensor internal to the transmission that I can read. In 2000 they change the sensor, but I have the voltage/temperature curves for each one. During setup it'll be calibrated in some manner so I know which one you have.

That said, I was planning to display the transmission temperature on the handheld screen. Outputting it to another gauge... might be possible, but probably not on the first or second revision.

The bare circuit boards should show up this week. My test vehicle is being delivered this week as well. Hopefully in a couple weeks I'll be to the point of testing control of the governor pressure solenoid. If that goes well, I'll have a lot more coding to do

Awesome.........I think we are all watching this progress very closely.

Are you able to output separate signals to an electronic speedometer as well as a cruise control output signal? If not, is it a difficult thing to split the VSS signal? I just don't know how to do this to make it work before the transmission controller. I also don't know how the OEM's do it either -- but am willing to learn........

Thanks,

Mark

I believe the VSS (two wire VR) signal itself can be split to go to two different places.

If the cruise control and electronic speedometer can both take a 0-12v square wave (at the same frequency), they can both be used on the one output from the controller.

I know that Dakota Digital makes a signal splitter and that's what I was going to use, but if it was possible to do it with your controller -- I would get rid of one more complication. Here is the Dakota Digital Universal Speedometer Signal Interface:

Dakota Digital Speedo Interface

If someone is going to be using the 46RE transmission, there is the problem of just the output from the transmission being an electronic signal. Those that use the stock speedometer cable setup will kind of be screwed, but there are workarounds (i.e. cable generators or changing to a GPS speedo). Those of us that will be using electronic speedometers will be all set -- I was just trying to get the electronic box count down in my car.

Mark

Several temperature features are in the logic. Both RE and RH. If below a certain temperature you cannot get OD or LU. This is to promote warmup and prevent fluid starvation to the OD when super cold. The OD is the last guy to get fluid in the lube circuit. It comes from TC output like a 727 but the fluid enters the case like normal - then splits off once inside to lube the OD and the intermediate shaft and trans geartrain.

If TOO hot - above i think 265 F, then OD is defeated, shifts to 3rd, and LU is turned on to reduce converter slippage and resultant heat build up. Once the temp drops, then OD is allowed.

The controls look at neutral safety position, temperature, shaft speed, outside temperature, engine speed, to name a few things.
If neutral safety reports N or P, you lose OD. We watch for engine speed reduction when we turn on LU, if we do not see an engine speed drop in a certain amount of clock time- we set a TC code. Some of the inputs are used to verify plausibility when we get certain bad inputs or no inputs. Not sure what your controls logic is going to include but you may want to incorporate some of these for safety reasons.

Will the transmission controller have a user customizable torque convertor lock up setting? With all of the different possibilities out there, this would be a great thing too.......

Yea, I'm not entirely sure on the interface yet, but it will likely have the option to set lock and unlock speeds at different loads (for both OD and LU).

Transman, thanks for the info

Any word on the development of the controller? How's it going?

Mark

I have it controlling the governor/OD/LU solenoids on the bench.

Hopefully this week I can test controlling the solenoid in the jeeps transmission while it's running.

Assuming that goes well... I have a lot more code to write

I for one appreciate you doing this, it's a lot of work but a really needed part. Plenty of 46RE's in the junkyard would suddenly become useable

So... I, umm, ran into an issue.

There is absolutely no room under the jeep to disconnect the RE plug to plug in my own harness

Seriously, any tips from anyone that's done it before? I can't even touch one of the locking tabs to attempt to release it. Not that the other tab is moving either