Freezing the Slushbox. Torque Converter on-demand lockup switch.

[taredog]

Originally Posted by Christ

NP, just make sure you check twice before you do anything, I may have been wrong on the TCM ground thing.

If you go to AutoZone.com, you can get wiring diagrams for your vehicle, they might have the one you need, which will tell you if it's common ground or TCM ground.

And, it's not technically Fiat-Chrysler, yet, I guess. Or has that changed again?

You are right. How could I doubt someone with a screen name like yours?

From the shop manual:

The solenoids receive electrical power from the
Transmission Control Relay through a single wire.
The TCM energizes or operates the solenoids individually
by grounding the return wire of the solenoid as
necessary.

This is referring to the solenoids that control the hold or drive clutches for the three planetary gear sets. This is pretty interesting stuff.

I went to trade school back in the '70s to be a mek-an-ick. Then my local draft board changed my career path Figured if I had to become an indentured servant for several years, they were gonna teach me a new trade. Worked out well for me.

While in school we had to tear down and reassemble several automatics. State of the art stuff like a fordomatic, powerglide and a ford c4. There was a shiny new turbo-hydramatic 400 that we weren't allowed to touch. Think the instructor was gonna put that in his 66 belair.

Anyway, gotta re educate myself on a lot of basics like sun gears, planet gears and annulus which I think they called something else back then.

I also think when I start screwing around with this the TCM is gonna throw a code and might put the tranny in limp mode.

Again from the shop manual:

The continuity of the solenoids and circuits are
periodically tested. Each solenoid is turned on or off
depending on its current state. An inductive spike
should be detected by the TCM during this test. If no
spike is detected, the circuit is tested again to verify
the failure.

If you or anyone else have any ideas on fooling the TCM, let me know.

I have manuals on the 45RFE, 545RFE, the complete 2001 Dakota shop manual and some schematics in pdf format so if anyone could use them pm me.

[taredog]

Originally Posted by orange4boy

Mole hills, my friend, mole hills. Out here cars come standard with a rate of climb indicator and an altimeter. Pressurized cabin is an option.



I guess Toyota didn't get the memo. Mine are 12V+ The injectors are grounded at the ECU but not the shift and TCC solenoids.

Taredog, Glad to have you on board. I can't help you with yours but you will be blazing a trail for others that do. Did you look for a kit? There are kits for some vehicles that are not too $$$ and they would come with wiring diagrams. Also, did you try any Dodge forums? Lots of guys doing it there or know how to.

LOL. I have driven through your territory. All in the eye of the beholder. Around here the elevation changes are measured in feet but an hour north they go from 1000-7000 in a few miles.

I hadn't read you entire post until now so didn't realize you were talkin to me.

I looked for kits, the Dodge and Jeep guys seem to be ignoring lockup on demand pretty much. There are several that have either reflashed or replaced the TCM to make the tranny a five speed so I am not blazing any trails on that. The problem seems to be that the Jeep TCM doesn't lock up the TC until about 50mph and doesn't shift in to fifth until about 55. All this can be dealt with eventually.

Should be interesting.

[Christ]

RE: Your TCM polling the solenoids

Check allpar.com, there is a thing on there that is a circuit that will fix the PWM issues on some mopar trans lockup circuits without throwing a CEL. The link might be earlier in this thread, even.

[RH77]

I've been wanting to post to this thread for a while, but my HDD crashed and the shop manual was tied-up in a backup file.

This is what I'm running into from the shop manual (I have read this chapter at least 50 times and find something new each time) -- a summary:

The lock-up valves control the range of lock-up according to valves A and B, and throttle valve B. When lock-up control solenoid valves A and B activate, modulator pressure changes. Lock-up control solenoid valves A and B are mounted on the torque converter housing, and are controlled by the TCM.

The Range:


The Algorithm:

(note the circled item -- any time the vehicle is in EOC, this value increases, is stored, and will not allow TC lockup until enough engine-on driving time has passed to even-out the load calculation)

The Schematic:


It may be hard to see, but TCM Pins A15 and A16 control the lockup (top right and the one right below on the diagram). It goes on to mention that each pinout is at 0v when not locked, battery voltage when locked. So theoretically, energizing (and isolating) each circuit at batt voltage would lockup each solenoid. The question has been, if I start cutting these and applying voltage, will it freak out and disable the system or worse?

RH77

[Christ]

Originally Posted by RH77

I've been wanting to post to this thread for a while, but my HDD crashed and the shop manual was tied-up in a backup file.

This is what I'm running into from the shop manual (I have read this chapter at least 50 times and find something new each time) -- a summary:



The Range:


The Algorithm:

(note the circled item -- any time the vehicle is in EOC, this value increases, is stored, and will not allow TC lockup until enough engine-on driving time has passed to even-out the load calculation)

The Schematic:


It may be hard to see, but TCM Pins A15 and A16 control the lockup (top right and the one right below on the diagram). It goes on to mention that each pinout is at 0v when not locked (5v system). So theoretically, energizing (and isolating) each circuit at 5v would lockup each solenoid. The question has been, if I start cutting these and applying voltage, will it freak out and disable the system or worse?

RH77

I'd try it and see what happens. Wire in a single +5V power source to both wires with a single switch, and if things go stupid, just remove the power. When you wire it in, don't cut the wires, just strip them back and wrap the +5VDC leads around them. Make sure that you put a diode in the line to your power source, though, unless it's your car battery with a resistor in it, so you don't go charging the battery from the ECU line.

[RH77]

Sorry, edited the post when I noticed that it was 12-volts.

The Diode is a good idea -- I might as well give it a shot. It takes forever for the Coolant Temp to satisfy the equation, then it takes a bunch of throttle to initially get it locked. EOC is almost punishment because of the equation.

I suppose I'll just have to remember to unlock them during stall speed or I suppose it would stall-out...

RH77

[Christ]

Yessir, you can stall your engine with a auto-lockup clutch, since there is no "give" anywhere. After testing and such, you'd want to install an RPM switch to automatically unlock them after certain RPM is satisfied, such as just off idle. (1200 RPM, probably.)

Basically, you'd use an MSD Vtec switch, which is RPM activated, normally open. This would ensure that you weren't able to be locked up at anything under whatever "pill" you install. As a manual disable, you'd just have a manual SPST toggle.

Your circuit should look something like this:

12VDC (ignition lead from fuse box) | RPM switch | SPST toggle | "Tee" in the wiring | Blocker diode on each line | A and B inputs on ECU wiring.

You Tee after the switch because you probably don't want to control both solenoids manually, and you need two blocker diodes because if you tee after a single blocker, you're creating a short circuit between the two solenoids, which will power both any time one is powered, throwing a CEL. You may also want a blocker in line w/ the ECU before your wire splice, so the ECU can't detect voltage on that line unless it's openly sending it out.

Total, that should be 4 blocker diodes, 2 that allow power from your manual switch, and two that block power going back to the ECU.

[brucey]

Have you been watching the transmission temperature? Thats the only thing I'd be worried about in doing something like this. I haven't seen it mentioned, but I thought that was the reason most transmissions dont always have the torque converter locked, in high load settings it causes a ton of heat.

I have a trans cooler on my car just because of some light towing and its cheap insurance. I believe 100 degrees above ambient is the quoted prime number.



Great numbers though!

[RH77]

Originally Posted by brucey

Have you been watching the transmission temperature? Thats the only thing I'd be worried about in doing something like this. I haven't seen it mentioned, but I thought that was the reason most transmissions dont always have the torque converter locked, in high load settings it causes a ton of heat.

I have a trans cooler on my car just because of some light towing and its cheap insurance. I believe 100 degrees above ambient is the quoted prime number

Excellent point. In my application, the trans cooler is essentially built into the radiator. I have it blocked and coolant temps get high -- I should also worry about the trans.

I'm also running about 80% synthetic fluid, which should hopefully handle the extra heat.

Trans temp is that one setting that's missing from the SG-II for monitoring. It may be an X-Gauge add-on, but I don't believe there's a sensor for it.

Christ -- great schematic for the inline wiring! I have been wanting to try this for a couple years now.

The next question, why doesn't the TC lockup if it's too cold?

RH77

[Christ]

Engine speed and emissions. And transmission/engine warm up times.