Hard shifting when a/c is on

I have a 03 chev impala and i have been noticing that after the engine is warmed up and the a/c is on the vech shifts real hard in the first 2 gears and a slight in the3rd gear too. It seems to run fine when a/c is off in the morning when I go to work. On my way home it starts off fine then (warms up) while in traffic, that is where my problem starts. I just did a tranny flush with new filter and the car has about 92xxx miles on it. I also noticed when it is cold if I step on the gas hard, the the there is a delay when the tranny kicks in. The car jumps and then goes with on problems at all until it gets warm. Any advice or help would be very good to me because I have no clue as to what it might be.

Take it to a trans shop and get it scanned for a DTC P1811. They do shift firmer with the AC on because the PCM commands higher line pressure.

I will do that thanks for the info Troy1

I will do that thanks for the info Troy1What you need to do is put a transmission cooler on her ,thats what I did with my 05 impala same thing with air cond on and it would loss power and eat the gas, with the cooler on her for around 70 bucks or so the gas milege is great and she does not loss any power.

What you need to do is put a transmission cooler on her ,thats what I did with my 05 impala same thing with air cond on and it would loss power and eat the gas, with the cooler on her for around 70 bucks or so the gas milege is great and she does not loss any power.


where do you get a transmission cooler? is it hard to install?