Torque Convertor Control

Goinbyyabig

Goinbyyabig

Free Thinker, Innovator
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Apr 12, 2009
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I would like to manually shift my convertor clutch when beating the truck hard. What I think I would like to do is shift the truck through all 4 gears, in tow haul mode for more line pressure and a firmer shift, but delay the convertor until a higher RPM or vehicle speed. The problem is the turbo barks pretty good on C.C. engagement in third, and really bad going into fourth. I really like the shift quality and feel in tow haul, but this problem keeps me driving in regular drive, and the tranny isn't very happy shifting when really pounding it, feels like it's right on the verge of slipping. I have an 06 cummins with a Suncoast triple disc, lowest stall available, input shaft, billet band, shift kit, dd pan, etc. I realize it's asking a lot but I would like to keep it all automatic, factory shift timing, and be able to manually engage the CC sometimes, but leave it stock for daily driving. Am I dreaming or does someone make such a device? I am aware of the ATS Co-pilot, full manual control, do I have other options?
 
Twenty seven reads and zero comments; I'll have to get on the phone....
 
You can lockout the TC lockup with a simple switch and resistor then manually turn it back on when you want it to lock. Is that what you are looking for?

Most of us lockup the TC with the switch for better performance. Not exactly sure why you would need it unlocked.
 
Awesome! That was what I'm hoping can be done! Do you or anyone else know what resistance I would need and how to wire it? I assumed the TCM would set a code if the TCC was requested but did not engage, based on RPM of the engine vs. the input shaft speed of the trans. I could simply put a switch inline to disable, but the TCM would need to be requesting apply to make it work manually. To manually engage, do I connect to power or ground?

I would rather not shift the trans under full power with the convertor locked, even if it costs me some performance; the low stall loads the motor pretty hard and I have no problems spooling the turbos, I just don't like the way it feels like someone slammed into the back of my truck when it shifts. Something's gonna break!!:poke: Shafts, pumps, convertors, etc. get expensive when changed on a regular basis!
 
I have wired me 2000 the same way you are talking about doing. I have one switch that is wired inline with the wire that goes from the computer to lockup solenoid in the trans. When this switch is off the CC will not engage and when the switch is on the CC works like stock and is controlled by the computer. I have a second switch that will manually lock the CC regardless of the position of the 1st switch. This switch is switching to ground in order to activate the CC solenoid.
My only problem is that when I flip the switch to not allow lockup I get a check engine light unless I have the trans relay removed and a jumper wire in place. I think that adding a resistor somewhere in there will allow the computer to think there is still a closed circuit when it is switched off. So far I have not been able to find any info on resistor size for this part of the problem.
You will also need to add a resistor inline to the manual lockup switch so that the computer does not sense a dead short when you switch to ground. At least on my truck this was necessary and if I remember correctly it is a 56K ohm resistor.
Hope this helps.
 
Both the TCC and OD circuit are monitored by the ECU for 5 to 100 ohms resistance, anything outside that will cause MIL's.

A 33 ohm 1/2 watt resistor on either ECU sense wire is enoug to engage the solenoids and keep the ECU happy and uncaring. The solenoids carry the load so you need little wattage in the resistor to keep it from burning out.

If you want remove the lock feature you will need to break the circuit between the ECU and solenoid then supply the ECU with a fooled signal in the same 5 to 100k ohm range. In addition, since the solenoid acts as a load you will need a larger resistor in watts to handle the voltage\amperage load to generate the needed resistance.

Guessing here but I believe an 80 ohm 4 watt resistor powered off a 12V 5 amp circuit should give you what you want and not burn the resistor up immedately. You would need to ohm out a solenoid and find the ampergae on your supply circuit to calculate the resistor size correctly.
 
Cantankerous1 said:
Both the TCC and OD circuit are monitored by the ECU for 5 to 100 ohms resistance, anything outside that will cause MIL's.

A 33 ohm 1/2 watt resistor on either ECU sense wire is enoug to engage the solenoids and keep the ECU happy and uncaring. The solenoids carry the load so you need little wattage in the resistor to keep it from burning out.

If you want remove the lock feature you will need to break the circuit between the ECU and solenoid then supply the ECU with a fooled signal in the same 5 to 100k ohm range. In addition, since the solenoid acts as a load you will need a larger resistor in watts to handle the voltage\amperage load to generate the needed resistance.

Guessing here but I believe an 80 ohm 4 watt resistor powered off a 12V 5 amp circuit should give you what you want and not burn the resistor up immedately. You would need to ohm out a solenoid and find the ampergae on your supply circuit to calculate the resistor size correctly.
Click to expand...

Thank you for the information. So clarify the solenoid ohm and amperage test for me. How exactly would I test the solenoid to find this info?

The ECU senses the resistance on the ground side of the solenoid which is the side that it switches on and off. A simple resistor from ground to the ECU wire wouldn't add the necessary resistance to fool the ECU? Or am I way off here?

Thanks
 
rockjeep73 said:
Thank you for the information. So clarify the solenoid ohm and amperage test for me. How exactly would I test the solenoid to find this info?

The ECU senses the resistance on the ground side of the solenoid which is the side that it switches on and off. A simple resistor from ground to the ECU wire wouldn't add the necessary resistance to fool the ECU? Or am I way off here?

Thanks
Click to expand...

A simple DVOM and a resistance test across the terminals of the solenoid will give the resistance in ohms. The amperage is a little harder as you need a good tester that test ampoerage draw when the solenoid is engaged.

The other way is find build the component to the max for 12V and whatever amperage the circuit supplies. Look at the fuse for the trans relay and that shoudl tell you the numbers. The key is getting the watts on the resistor high enough to handle the current draw of the circuit based on the resistance used.

Not enough of an electrical engineer to know it by heart, I have to look it up or rely on a supplier to know the sizes when I tell them what to do.

A simple resistor will engage the solenoid on the ground side and keep the ECU happy, it works the same way if oyu replace the solenoid with a resistor but then the resistor has to take the load in amps the solenoid did to last or it will burn up from the heat generated. Ground side is generally low amperage because the load component takes all that and dissipates the heat.
 
Thanks so much for the thoughtful replies; I just had an idea, wondered if you think it will work. How about I just buy a convertor clutch solenoid and wire it into the switch so the computer always stays connected to the correct resistance and load no matter if the functional or dummy solenoid is connected? Then, with the "automatic/manual" switch in the manual position, I could manually apply the TCC with another switch when desired, and the computer is always happy. Opinions? Problems? Thanks, Rob.
 
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