or is it my imagination? either way its annoying.

I assume its to smooth out the transition

 

Wouldn't doubt it. Believe it did with the gmt900 series. It's been too long and too many mods to run logs to verify.

 

Doubtful. Be absolutely retarded if so because it would offset/negate the fuel savings of 4cyl mode.

If it did, you'd notice the RPM jump up and down a few hundred rpm or so when it engaged/disengaged. I haven't noticed it doing that.

If I get a few minutes today I'll datastream my truck and monitor the lock up. But my money is on no, that it does not.

 

I think it unlocks during the switch then locks back up after 5 seconds or so. i do get a rpm bump when it happens.

I'm pretty sure this is whats happening now, but now i wonder if its supposed to, does everyone else's truck do the same..?

 

 

I read your post wrong. During switching, maybe, I can't say 100%. There are a couple of switch on/offs of the tcc that I wasn't sure what caused them, because I was watching for typical TCC operation, the cyl deactivation could very well have been it.

I will tell you that if you're familiar at all with how TCC used to work (up till mid 00's) things have drastically changed. I saw the same basic activity I just saw with my truck with a late 00's Cadillac CTS. They run the converter at just about all times.

I shot this video on the fly and since I read your post wrong I wasn't eagle eyed on the cyl deactivation/moment of activation deactivation and TCC.

I gave you a shoutout in the description

edit: watching the vid a little closer looks like it does switch on and off during the cyl activation.. I have been in a big hurry during filming this and since filming so I haven't had time to analyze it.

 

at around 2:10 in the vid it switched to 4 cyl mode and there was a dip in the graph so it appears it did turn the tcc of during the 8 to 4 switch