This in my 95 Z. I noticed last weekend when I went to do a burnout on the street that my car upshifted to 2nd even though I had the selector in 1st. WTF...

Also from a roll it will up shift to 2nd gear at a low RPM. If I leave it in D it will run up to its shift point and shift fine.

Anybody ever have this problem??

 

It's part of the design to protect the car from the driver. If you are getting an upshift in the burnout, you are reaching the programmed shift point. IMO, an upshift is better than a rev-limit engine cutoff during a burnout.

This is not a full manual control trans by any means, even when you select other than D or OD.

Some 4L60E transmissions have a 2nd gear start feature for slippery conditions: when you select "2" from a stop it will start in 2nd, or when you select "2" while moving it will go into 2 regardless of throttle position. This allows a short shift in second, and the ability to stall the converter against the brakes without spinning the rears to check stall speed if you wish. It works on my C5 anyway.

If you don't completely stop and then accelerate at less than WOT, often the trans will not downshift into 1st and you have 2nd gear. While that can be annoying, I always thought it might be intentional to discourage rolling thru stop signs. Seriously, your trans sounds normal to me.

The trans is quite sensitive to throttle position. At WOT (wide open throttle), lifting just a fraction of an inch when you are approaching a shift point will give an early shift. My C5 is now set for 6200 WOT 1-2 shift, but if I'm not in that much of a hurry, I can get a 5800 or 6000 shift with just a llittle lift. It works on cable throttle cars too.

My $.02

 

Well the transmission just started doing this. It will shift at any giving RPM when in low. 3K,4K,ETC. Its not even close to the shift points.

 

it only shift at shift points when you press the pedal to the metal

 

Hmmmm...Its at 100% throttle when this happens

 

that's bad, real bad

 

the 4L60 and most other auto trannies will shift up to "idiot proof" them from certain kinds of drivers. Have the computer checked for correct shift settings, also have u installed a shift point modifier, like the one from jet? a friend of mine had some problems w/ those, better off using hypertech prog to mod shift points. (execpt 93's no elec controller for tranny)

 

I'm still not sure what's really happening....take it to a professional--they will know if it is right or not. Hard to diagnose tranny probs with words