Two parts to DOD/AFM when off - V4 and 'jake brake'?

[techntrek]

I finally decided I was tired of AFM. Contrary to GM's claims I can feel it when it is engaged and there is a noticeable lag when it disengages. "Feel it" is understating it, more like hearing a loud rumble, and a strong vibration like the engine is detonating.

So I changed my tune parameter last night to turn it off. My drive to work this morning went partly as expected - it never entered V4 mode. Great, no noise or vibration and a little more responsive! But there was one thing I wasn't expecting. Before, 5-6 seconds after letting off the gas the engine would enter a 'jake brake' mode which created a noticeable drag. I do a lot of towing and like this. I didn't feel it at all during my morning drive - it now feels like my old '93 Caprice which just glides along forever after you let up on the gas pedal.

Is there any way to lose V4 mode but keep the 'jake brake'? I figured turning DOD off would only keep it in V8 mode.

[mikel]

if it was using the AFM to create this load, then it just wont work when its disabled.

[techntrek]

When I feel the engine braking kick in it doesnt enter V4 mode, at least the display doesnt indicate it. I figured it was mostly injector cutoff. So nobody else has reported this?

[mikel]

No, I have never seen this reported to be honest.

[techntrek]

I paid attention to the instantaneous mpg display on the way home and it is definitely cutting the fuel supply. mpgs go to 99 until slower speeds (when it slowly increases fuel to keep the engine running). I guess what I'm missing from the equation is the cylinder shutoff, like you thought.

I won't be towing for a few weeks so I'll keep things as they are for now...