2010 SS1, strange (to me) quick blips of throttle

[Robar1]

Hi, I have a new to me 2010 SS1, auto. Sometimes when making a partial acceleration (as in just speeding up a bit) the engine makes a few quick blips of the throttle. Sounds like if I had a manual car I pushed in the clutch, tapped the throttle 3 times real quick and then accelerated. I can't say as the acceleration does not start until after the blips, but the car does not act like those blips of throttle are getting to the pavement. I have searched for some time but I can't find where anyone else has mentioned this. I get the blip of throttle when downshifting, but this just happens on its own. Oh, it seems like it happens in auto sport mode more often than the normal drive mode. Is this common, and what is it? Thanks

[radar1972]

I'm sure the real experts here will chime in, but to me it sounds like it is what some call the 'flutter' of the AFM (Active Fuel Management) system as it switches back and forth between 8-cylinder and 4-cylinder operation.

[Robar1]

It just sounds crazy. To me, if I were in a Charger next to a car that did that I'd think he was kind of calling me out!

[InFiD3ViL]

I have also had strange behavior from my transmission.

If I drive aggressively in Sport Mode, but NOT using TapShift, the car will downshift very hard, blipping the throttle just as if I was downshifting hard via TapShift. It does this when I stop at a light, stop sign, or make a turn.

It is only if I have been driving very aggressively though, which made me think it was programmed to do this. If I start to drive more normally, it takes itself out of this 'mode' on its own, downshifting like a normal transmission would...without the engine braking that TapShift gives you.

[SlingShot]

^^^

It's call P.A.S. Performance Algorithm Shifting and is programmed into the trans. It is only available in sport mode, and what causes your trans to rev match when downshifting. When you are driving it hard, the trans shifts based on your driving style at the time. Just start driving normal or put it into drive to turn it off.

[Robar1]

Interesting, thanks. ^^^^

[qcman]

Typically that aspect of the trans comes in if you've been rodding on it in my experience. It sounds like this happens all the time? And it will kind of hold the gear you are in instead of upshifting right away thinking you may still want to giddy up some more.

What you describe doesn't sound like that to me. And I thought it only occurred in Sport Mode not Drive but not sure on that one....

[rontammy0]

Sounds like you may have a trans tune.

[InFiD3ViL]

Originally Posted by SlingShot

^^^

It's call P.A.S. Performance Algorithm Shifting and is programmed into the trans. It is only available in sport mode, and what causes your trans to rev match when downshifting. When you are driving it hard, the trans shifts based on your driving style at the time. Just start driving normal or put it into drive to turn it off.

Phew, that is definitely a relief. I was concerned at first that my transmission was acting up, but I had read something about this last year and could never find anything further about it.

What I don't like about it is how aggressive it is. Like its dropping into too low a gear at times, causing it to blip very high.

But I think that is just because I tend to baby the car and do very little high rpm driving. I am mainly trying to take it easy with the high rpms until I change out my 122k mile AFM lifters and replace with LS7 units.

Thanks man!

[Robar1]

Could be sport mode only but I can't seem to find a way to reproduce it on demand. It just seems unexpected.

[qcman]

Originally Posted by Robar1

Could be sport mode only but I can't seem to find a way to reproduce it on demand. It just seems unexpected.

Assuming it is what's been proposed it would be random in the sense the trans would determine when to engage it or not based on certain driving situations. I only ever had it kick in maybe twice in the time I've owned my car. The first time freaked me out so I backed right off LOL thinking something was wrong.

Now that I'm tuned I drive in D nearly all of the time whereas I was in S all the time before tuning. D has much firmer shifts than when stock and S is holy $hit firm so with using S much less I'm even less likely to come across that condition. I really should use S more now that I think about it.....

I would pay attention to what you are doing or how you are driving before this occurs. If you are rodding on it thats normal, if even happens continuously that's not.

What I do recall is it will hold the gear even if you back off the throttle whereas it would usually upshift under normal conditions if you let off the throttle. Sorry for the long post....

[SlingShot]

Easy to reproduce, put it in Sport mode and don't touch the paddles. Now just blip the throttle to force a downshift and your there. I can do it on demand in both my ZL1 and SS Sedan.

[qcman]

OP is this what you have experienced?

From the manual.... it seems and I recall this being the case that lateral g's (cornering) affect and encourage its engagement too. The 6 speed auto ZL-1 behaves differently than the SS & V6 in terms of engagement & how it goes through the motions.......

While driving in Sport Mode, if TapShift has not been activated, the transmission determines when the vehicle is being driven in a competitive manner. The transmission may remain in a gear longer than it would in the normal driving mode based on throttle input and vehicle lateral acceleration. If there is a rapid reduction in throttle from a heavy throttle position, the transmission will maintain the current gear up to near redline rpm. While braking, the transmission will automatically downshift to the next lower gear keeping engine speed above approximately 3000 rpm. If the vehicle is then driven for a short time at a steady speed, and without high cornering loads, the transmission will up-shift one gear at a time, until 6 (Sixth) gear. After shifting to 6 (Sixth) gear, or coming to a complete stop, the transmission will return to normal Sport Mode shifting.

[Robar1]

Originally Posted by qcman

OP is this what you have experienced?

No, it is more like driving up the on ramp and getting into the lane and then slightly accelerating into the next lane and the car goes, vvrroom, vvrroom, vvroom really fast and only a few hundred rpms. I'll pay better attention tomorrow to and from work.