Hesitation document

[TA427]

#PIP4112J: Sag Or Hesitation On Acceleration (Normal Operation Characteristics) - (Jul 21, 2011)


Subject: Sag or Hesitation on Acceleration (Normal Operating Characteristics)


Models: 2007-2011 Cadillac Escalade, Escalade EXT, Escalade ESV

2006-2009 Cadillac XLR, XLR-V

2007-2011 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2006-2011 Chevrolet Corvette

2007-2011 GMC Sierra, Yukon, Yukon XL

2008-2009 Pontiac G8

Equipped With a Gasoline Engine and Automatic Transmission




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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
Some customers may comment on a sag or hesitation when accelerating under the following

conditions:

When coasting with a closed throttle and then aggressively applying the throttle. Examples of this maneuver include a rolling stop or a lane change maneuver. In this type of maneuver, even though the accelerator is applied aggressively, the throttle blade is opened slowly for up to 0.7 seconds to help minimize driveline lash and clunking.

Also in a 6L80 or 6L90 (RPOs MYC or MYD) equipped vehicle when making a hard, complete stop with a closed throttle, immediately followed by an aggressive throttle opening the transmission downshifts may not be completed by the time the throttle is opened. As a result approximately 0.5 seconds of zero torque may be commanded to allow the shift to first gear to occur.

Recommendation/Instructions:
Both of the above conditions are a result of Torque Management and both of these conditions should be considered normal and no repairs should be attempted. Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

[foreosu]

So in other words, "deal with it". Lovely.

[MoonPie]

That's fucking silly

[TA427]

Only if you have a stock tune,mine does not do this anymore !

[Zaphod B]

So in other words, "deal with it". Lovely.

... and that is precisely the shifting behavior that drives me nuts.

[TooManyHobbies]

It is this dangerous behavior that started me on the modding path. Went to make a pass on a two lane and the damn thing would not go. Hurry up and shift dammit, I am hung out here now. It took what should have been an easy pass to one that was a little too exciting.

[edfiero]

Yes, I've felt this is dangerous as well. You roll up thru a yield/merge area, then want to punch it. You've committed, You got traffic coming right up your ass and the car won't go.

Can VMS or others tune out this "feature? or at least reduce the delay.. say from .7 down to .2?? I already have the VMS tranny tune, but still experience this delay. I wonder if I can specifically ask for this delay to be reduced/removed

[edfiero]

BUMP.. anyone know what the various tuners can do relative to removing the delay on the throttle opening?