Torque converter.

2005 La Crosse. Do these cars have a lock up torque converter? Can it be disabled?

Yes they do. What is the problem?

At low speed and low throttle it seems that the torque converter is locking up and then unlocking. is there a switch on the brake pedal like was first used that you needed to apply the brake to shift. I just had the transmission flushed and it is working better ,but not this hard lock unlock. Is there any vacuum from the intake to the trans control? Thanks

No vacuum, all electronic controls from the pcm. To avoid unnecessary repairs you should have it scanned with the proper bi-directional scanner to see pcm commands and tcc functions.

Before you just go disconnecting the tcc you should really be sure that's the problem. Converter lockup shouldn't be that noticeable of a difference and you will have more problems if you bypass it. Can you describe your problem in a little more depth?

Are we talking about the TCC engaging/disengaging, or about harsh shifts?

Have you scanned for transmission codes?

Are we talking about the TCC engaging/disengaging, or about harsh shifts?

Have you scanned for transmission codes?
This is exactly what I am thinking.