Gear Shifting

My 2003 chevy impala 3.4 has 109,000 miles. i dont know if its the transmission or what. when i start driving it it drives and shift fine and like when i accelorate more when its like in 1st,2nd,3rd gear.it then starts to shift in gears hard. when i turn the car off and cut it back on it shifts normal till after like a few mins of driving. when in on the freeway it doesnt do that. it only start shifting in grear hard when im in town stopping going. Its bugging me i dont want to go out of town and then it start giving me problem its not the tranmission so then what can it be? can ANYONE help me please?

on a 2003 chevy impala. does anyone know how much do mechanics charge to change and replace the solenoid... and how important is the solenoid and what does it do?

Come on now, what solenoid??

Needs to be scanned with a trans function scanner to look at various internal trans shift patterns and solenoid functions.

My 2003 chevy impala 3.4 has 109,000 miles. i dont know if its the transmission or what. when i start driving it it drives and shift fine and like when i accelorate more when its like in 1st,2nd,3rd gear.it then starts to shift in gears hard. when i turn the car off and cut it back on it shifts normal till after like a few mins of driving. when in on the freeway it doesnt do that. it only start shifting in grear hard when im in town stopping going. Its bugging me i dont want to go out of town and then it start giving me problem its not the tranmission so then what can it be? can ANYONE help me please? The tranny has a hidden code stored for the shift soilnide the hidden code is p1811 code,get someome who knows how to use a scanner to find it

Correct, stated in post # 2.

Since this is the same issue your two posts have been merged together otherwise all it does is cause confusion and redundant replies.

We're assuming you are referring to the pressure control solenoid (PCS). It controls line pressure in the automatic shifting modes. The hard shifts is a result of possibly a P1811 DTC setting which commands maximum line presssure, thus the hard shifts. Also, it disables shift adapts. It does not normally turn the SES/CEL light on either.

thank u do anyone knows how much it will cost to get my tranny scanned if i go to the dealership. i dont have a warrent anymore. and do anyone know around how much it would cost me to get it fixed?

Any trans shop can also do this as a rule, if the solenoid is bad the usual labor to do just that is about 5-6 hours.