Torque Converter lock up

[First c10]

Wow. I guess I need to do more reading ....a lot more reading or just buy hp tuners and start playing.
Thanks
Well I am sure Shawn will be able to take care of this for me. When we get a chance to hook up.

[67Steven]

Geez, I think my brake light switch is wrong now, too.

2008 L92/6L80 and I have the blue wire getting +12v on all the time except when brake applied. As I understand it now, this is NOT correct? I will change it over on the relay I suppose.

PSI conversions has it this way in their instructions for the 6LXX series transmissions.

[First c10]

Hey guys so I had a chance to hook up with super73 great guy!!!. We spent about 2 hours working on the shift points and fuel delivery. He had to richen up the fuel mixture at higher throttle position. The funning thing is I had my blue wire to the lock up hooked up so it had 12 volt when the brake was applied and we never seen the TC lock once. No matter what we did full throttle,1/2, and normal driving. But after we set the shift point. The 6l80 is nice to drive now with no unnessesary up shifting and downshifting.
On mail order tunes, Only worth getting your motor started and running not tuning or anything else. Just my two cents!!!

[Houston Ben]

So....is there any other way to lock it up? A switch maybe?

[First c10]

I asked the question if it needed to be locked up or not. With stock swap really doesn't hurt he said. Is that correct? I am not sure. But it drives nice.

[dayj1]

Originally Posted by First c10

The funning thing is I had my blue wire to the lock up hooked up so it had 12 volt when the brake was applied and we never seen the TC lock once.

How exactly did you have it wired up? Blue wire directly to the brake switch, through a relay, or ?

[First c10]

Well I have tried it both ways with the relay and without. Positive with and without the brake pedal pressed. Currently it is without relay so positive when the brake is pressed and negative through the brake light bulb. I put my fluke on it when I tried the relays and got the same result that the reason for removing the relay.
Ground with brake up. 12 volts with the brake pedal pressed.

[dayj1]

Originally Posted by First c10

Well I have tried it both ways with the relay and without. Positive with and without the brake pedal pressed. Currently it is without relay so positive when the brake is pressed and negative through the brake light bulb. I put my fluke on it when I tried the relays and got the same result that the reason for removing the relay.
Ground with brake up. 12 volts with the brake pedal pressed.

That sounds good on the wiring. It's just as important that the ECM sees ground when the brake is not pressed as the 12v when it is pressed. You've got that covered by tying into the brake switch directly.

[First c10]

Weird thing is that even with that the TC never locked up. Even if I stepped on the brake while driving. We never saw the TC lock up.

[Hart_Rod]

Originally Posted by First c10

Weird thing is that even with that the TC never locked up. Even if I stepped on the brake while driving. We never saw the TC lock up.

How do you know that the TCC wasn't locked? What PID were you logging?

[67Steven]

Originally Posted by dayj1

That sounds good on the wiring. It's just as important that the ECM sees ground when the brake is not pressed as the 12v when it is pressed. You've got that covered by tying into the brake switch directly.

So you are saying that it should have a ground lead to 87A in this diagram? If you don't, the TCM will not see a ground through the brake light switch, will it?

[First c10]

Rob
Shawn said it never locked up while we were logging and tuning

[First c10]

Yes some say you need a resister!

Originally Posted by 67Steven

So you are saying that it should have a ground lead to 87A in this diagram? If you don't, the TCM will not see a ground through the brake light switch, will it?

[Hart_Rod]

Originally Posted by First c10

Rob
Shawn said it never locked up while we were logging and tuning

Did you guys use HPtuners? If so, can you send me a copy of the log? I would like to compare it to mine. Thanks,

Rob

[dayj1]

Originally Posted by 67Steven

So you are saying that it should have a ground lead to 87A in this diagram? If you don't, the TCM will not see a ground through the brake light switch, will it?

Correct, 87A should be grounded. While the relay will work as shown (with 87a grounded), I'd scrap it all together. On a Gen IV ECM, you can just run the TCC lockup signal wire (purple in the diagram) directly to the wire going to the brake lights (blue in the diagram). No need for a relay and it does the same thing with no extra parts.

[Hart_Rod]

Originally Posted by dayj1

Correct, 87A should be grounded. While the relay will work as shown (with 87a grounded), I'd scrap it all together. On a Gen IV ECM, you can just run the TCC lockup signal wire (purple in the diagram) directly to the wire going to the brake lights (blue in the diagram). No need for a relay and it does the same thing with no extra parts.

Dayj1 is correct. You only need the relay with the resistor if you are running LED tail lights.

[First c10]

Yes we did. Shawn has the file.

Originally Posted by Hart_Rod

Did you guys use HPtuners? If so, can you send me a copy of the log? I would like to compare it to mine. Thanks,

Rob

[Hart_Rod]

Originally Posted by First c10

Yes we did. Shawn has the file.

you can email it to robhartley@aol.com.

[First c10]

I will let him know.

[Super73]

Scott and I spoke this morning after some more log reviews and doing a little more research on the lock up function for 6L trans. It appears the traditional pwm lock up is not used and that the tcm might rather adjust line pressure to the lock up clutch. I still need to do more digging but that would explain why I never saw a tcc pwm %.

Hart, I will e-mail you the tune some time tonight.

[Hart_Rod]

Originally Posted by Super73

Scott and I spoke this morning after some more log reviews and doing a little more research on the lock up function for 6L trans. It appears the traditional pwm lock up is not used and that the tcm might rather adjust line pressure to the lock up clutch. I still need to do more digging but that would explain why I never saw a tcc pwm %.

Hart, I will e-mail you the tune some time tonight.

Sounds good.

[67Steven]

Originally Posted by dayj1

Correct, 87A should be grounded. While the relay will work as shown (with 87a grounded), I'd scrap it all together. On a Gen IV ECM, you can just run the TCC lockup signal wire (purple in the diagram) directly to the wire going to the brake lights (blue in the diagram). No need for a relay and it does the same thing with no extra parts.

Okay, I am now confused (not hard to do) I just went out and checked, the brake light side of the switch does not ground when brake is off, so how does the TCC have a ground just hooked to the brake light feed?

Wouldn't the above diagram be exactly the same as just running the TCC wire directly to the brake light wire? If the TCC in fact needs to have a ground when not on, it does need a relay to produce that, doesn't it?

Or am I not thinking through this correctly?

[Andy4639]

I don't know if mine fall's under this but my 4l80e transmission with a 2001 ECU has the cruise controll brake switch hooked to it and it works fine. Shifts good and downshifts fine. Locks and unlocks as it's suppose to.
Here is a typical relay hook up for 12 volts +.

[Hart_Rod]

Originally Posted by 67Steven

Okay, I am now confused (not hard to do) I just went out and checked, the brake light side of the switch does not ground when brake is off, so how does the TCC have a ground just hooked to the brake light feed?

Wouldn't the above diagram be exactly the same as just running the TCC wire directly to the brake light wire? If the TCC in fact needs to have a ground when not on, it does need a relay to produce that, doesn't it?

Or am I not thinking through this correctly?

It grounds through the tail light.

Originally Posted by Andy4639

I don't know if mine fall's under this but my 4l80e transmission with a 2001 ECU has the cruise controll brake switch hooked to it and it works fine. Shifts good and downshifts fine. Locks and unlocks as it's suppose to.
Here is a typical relay hook up for 12 volts +.

Andy - 6L80 TCC are wired differently than the 4L80s.

[Andy4639]

OK I thought so but after reading all this I just wanted to make sure.