PCM or PCS Issue?

[CyxRyan]

2005 GP GT 123k

I have heard of many other's having same problem as I have with my car sometime's but can't really find what the problem is. Sometime's my car will start to shift hard like a small jerk in between gear and the higher the gear the less of a jerk it become's. When it doesn't happen, my car will shift smooth in all gear's no problem whats so ever. Sometime's while driving everything will be fine then out of no where the jerk's will come back... Only thing I found out the kinda fixes the issue is when I turn my car off for a few seconds then back on it will go away. I never have had a code pop up and im not sure if one would pop up for the PCS. I have taken in to trans shops and never got a code to pull up either =/

Any advice if its either a PCM related issue or a PCS going bad?

[Explicit_Spade]

Good trans fluid level and color? When was the last time the filter was changed and new fluid was put in?

[BillBoost37]

When you say no code pops up, do you mean no light ever comes on? Many codes set in the pcm without turning on the light. The code P1811 (usually pcs related) is one of the codes that does not turn on the light. This code also resets with ignition off.

Your issue sounds pcs related. A cheap bandaid is a shift kit.

[CyxRyan]

I have had it checked by tran's shops that checked for codes and nothing came up but could feel the jerk. They said slipping and to get it rebuilt by them -_- .....

[02NavyBlue]

Our 03 impala does the same thing, I'll get around to doing a fluid/filter and shift kit eventually. It does a slow shift from 1-2 a few times then does a hard shift, almost like the computer is trying to adapt to the original slow shifts. Of course nobody ever notices the slow shifts, just the hard ones lol.

Edit: and this only happens sometimes. It shifts perfect 95% of the time, but when it shifts slowly a few times then you can expect a few hard ones.

[CyxRyan]

Yeah I would say it shifts pretty good most of the time. Trans fluid was changed about 6k miles ago with new filter and before that the fluid was red.

[BillBoost37]

You had it checked by trans shops, meaning you turned off the ignition, walked in.. then turned it back on (aka resetting the code)?

Next time it does it, don't turn it off and have it scanned. Likely you'll see a P1811 code.

[CyxRyan]

It was acting up during the time they took it for a test drive but just said no codes that it needs rebuilt. Why wouldn't the trans shop tell me that those kind's of codes would turn off when the car is turned off?

[BillBoost37]

Maybe they didn't feel it was important for you to know?