Torque Converter Lockup Switch

Avalanchediver · January 19, 2009

Can anyone tell me if I can wire in a switch to lock up my torque converter manually? I have a 2002 Denali XL. My last truck, an Excursion, had a switch. All I had to do was ground a wire in the trans harness with the switch and it would lock up the converter. I can not find any info on regarding the Denali. The switch is awesome for towing, and miss having it like my last truck did.

Thanks,

Eric

txab · January 19, 2009

Are you wanting to have the option of not having the converter lock while towing?

97SierraGMC · January 19, 2009

run it in 3rd gear...

Avalanchediver · January 19, 2009

Are you wanting to have the option of not having the converter lock while towing?

No, I want to be able to lock up the converter and keep it locked up until I unlock it. Another words, I want a switch so I can over ride the compter and lock it when ever I wnat it locked.

Any information would be appreciated.

txab · January 20, 2009

What about the way it shifts now is causing a problem. I'm just curious. Mine locks at the optimum time and stays locked until it is time for it unlock, you know, downshifts.

Avalanchediver · January 20, 2009

What about the way it shifts now is causing a problem. I'm just curious. Mine locks at the optimum time and stays locked until it is time for it unlock, you know, downshifts.

Nothing wrong with how it shifts, I just want the control of a switch. Perhaps it can not be done with this trans. It was so simple on the Ford.

2005LT · January 20, 2009

I almost did this on my old 1995 GMC Sierra 6.5L turbo diesel. It was similar to what you describe, just placing ground on a certain transmission wire with a switch on the dash. Never ended up doing that mod though. That would keep your converter locked in all gears if you wanted it to be which is kinda cool and good for towing.

Oh, wait a sec, doesn't Tow/Haul in these newer trucks lock the converter in 2nd gear or higher already? I didn't play around enough with the T/H in my 2005 before I sold it.

Rat4go · January 20, 2009

I did this on an early 90's 4L60 that did NOT have electronic control for anything but TCC (behind a big block in a 91 Camaro) and tied it to a pressure switch so it would only lock in 4th.

I think with the new transmissions in newer vehicles, even if you could figure out how to do this, your government probably makes the car companies 'detect' a stuck valve or solenoid or whatever, and set a code. And we wonder why our vehicles cost $50K!?!?!

Rat4Go

chrisbmo2000 · January 20, 2009

Are you wanting to have the option of not having the converter lock while towing?

No, I want to be able to lock up the converter and keep it locked up until I unlock it. Another words, I want a switch so I can over ride the compter and lock it when ever I wnat it locked.

Any information would be appreciated.

NOT A GOOD IDEA the diffrence between what you want to do and what your ford had is the ford computer was programed to "see" the switch and work around it and shift appropriatly your gm does not have this "feature" if you locked up the convertor and forgot to unlock it you will have a VERY big paper weight seems like more of a PITA to remember to unlock the TCC.....there is a reason why GM did not put one in. I think your best bet is to leave it alone. If you still want to do it it is very simple to do.

Crazy Canuck · January 20, 2009

Although I could be mistaken, I belive one of the reasons that the TC will disengage full lockup is to lower the temp. to prevent overheating. just my $0.02 but I am not sure I would want to defeat that feature.

Crazy

97SierraGMC · January 20, 2009

i thought that was the other way around..

i didn't think it locked up until 4th gear and then it locked up..

chrisbmo2000 · January 20, 2009

your right riggs......4th gear and then it also provides "direct" drive for the tranny for fuel economy.

svensk · January 20, 2009

get a tune and have them make custom lockup parameters for you.

Avalanchediver · January 20, 2009

Are you wanting to have the option of not having the converter lock while towing?

No, I want to be able to lock up the converter and keep it locked up until I unlock it. Another words, I want a switch so I can over ride the compter and lock it when ever I wnat it locked.

Any information would be appreciated.

NOT A GOOD IDEA the diffrence between what you want to do and what your ford had is the ford computer was programed to "see" the switch and work around it and shift appropriatly your gm does not have this "feature" if you locked up the convertor and forgot to unlock it you will have a VERY big paper weight seems like more of a PITA to remember to unlock the TCC.....there is a reason why GM did not put one in. I think your best bet is to leave it alone. If you still want to do it it is very simple to do.

I understand the danger, but still want to do the mod. I can not find any info on the GM system operates. Do I need to ground a wire to engage the TC lockup or do I need to add 12V? How can I determine which wire I am lookinf for? Any help will be appreciated.

Thanks,

Eric