Brake Switch Torque Converter lock out???

[Curt - TN]

For those of you who of done an LS with a 4L60 or other electronic transmission and the master under the floor what have you done for a Torque Converter lock out when the brakes are applied?

I installed a inline brake pressure switch for the brake lights but I cannot find a dual switch to feed the signal to the computer to disengage the torque converter.

I may have to rig a manual switch to the peddle below the cab.

[dsraven]

can't remember exactly what the brake light switch looks like but it is a lever action afair right? just install another switch dedicated to the tcc, or install a relay off the existing brake light circuit to turn on/off the tcc when the brakes are applied/releasd. use "hot ign on" for a power supply so it is only powered when the key is on. just make sure to adjust the switch properly so the tcc releases fairly quick when the brake pedal is touched. an original switch would piggy back off the brake light switch with it's own power supply.

[AB6DO]

On my 1948 3100 I followed LT 1 Swap's directions on the brake switch. My master is under floor using stock brake pedal. I used an inline pressure switch for the brakes and a lever switch, like the original, for the TCC control.

[_Ogre]

easy peasy
this is how ogre did it

[MIKESAD50]

this was something I saw recently.
I'm going to try that to start with.

Ripped from the LT1swap.com site

Brake Switch Signal - For automatics with lock up converter, the PCM needs signal when brake pedal is pressed. However, the signal needed is opposite how you're brake lights work. The PCM wants 12v+ constant on this wire when brake IS NOT pressed, and OPEN Circuit when the brake IS pressed. If you vehicle was equipped with a lockup trans to begin with, you probably already have the proper normally closed switch mounted by your brake light switch. If you do not, you can use a relay to perform the same thing. On most relays, there are 5 terminals, 2 of them turn the relay ON when provided ground/power. There are then a normally open leg and a normally closed leg on the relay and a supply. By feeding 12v+ on the supply leg, and hooking the Brake Switch Signal wire to the normally closed leg, you will now have the correct signal for the PCM. When the brake is pressed, 12v+ flows to brake lights, tap into this wire, and run it to the relay to turn the relay on. This will cause the normally closed leg to become open, thus turning OFF the 12v+ signal to the PCM. When you release the brake pedal, the relay will turn OFF, and then feed 12v+ to the PCM.

[Curt - TN]

Thanks for the ideas!

[jweb]

What happens if you don't hook up the TCC? I did my swap last year and wasn't aware of this.

[Curt - TN]

Originally Posted by jweb

What happens if you don't hook up the TCC? I did my swap last year and wasn't aware of this.

My understanding is the Torque converter will not unlock thus not allowing it to disengage when stopping or stopped. I am thinking this could cause a constant pull when in drive and could make it very hard to stop.

Have you been driving it ok?

I learned about this on my last build and had no idea either

[jweb]

Originally Posted by Curt - TN

My understanding is the Torque converter will not unlock thus not allowing it to disengage when stopping or stopped. I am thinking this could cause a constant pull when in drive and could make it very hard to stop.

Have you been driving it ok?

I learned about this on my last build and had no idea either

It does seem hard to stop, I thought that was a brake issue since I switched to rear disc and a new prop valve. Now I have to add this to my pre-summer to do list.

[Curt - TN]

Originally Posted by jweb

It does seem hard to stop, I thought that was a brake issue since I switched to rear disc and a new prop valve. Now I have to add this to my pre-summer to do list.

Yeah, the trans is always pulling without it. Glad you caught it now

[jweb]

Originally Posted by Curt - TN

Yeah, the trans is always pulling without it. Glad you caught it now

Now to figure out which wire goes where. I hate wiring.

I have an '04 GTO which list 2 different TCC wires

GY/RD 422 TCC Solenoid Valve Control

BN 418 TCC PWM Solenoid Valve

Any idea which one it is and which one on the transmission end?

Thanks for the help, sorry for hijacking your thread.

[mongocanfly]

Jweb..try a post over in engine and trans section...clinebarger would probably know