hard gear shift

[jjthornt]

I have a 2002 Pontiac Grand Am GT 3.4 Ram Air, I just bought it two weeks ago, and it had some shudder when i would accelerate around 45-60 mph. I took it to the dealer and he serviced the transmission. The shudder went away, but now it shifts hard into reverse, drive, and 1st gear. The service engine soon light is also on, as before. When he serviced the engine it went away, but now it is back, I dont know if he knows what he's talking about or if I'm getting screwed over?

[crazy Jim]

what exactly was done to the tranny when it was "serviced" and what code is the ECM showing?

[jjthornt]

I'm not sure what code it was showing, he just said the service engine soon light was on because he forgot to plug something back in after changing the transmission fluid and taking the pan off...im not exactly sure...

[crazy Jim]

replaceing the transmission filter may help your situation if it was not done while the pan was off.

[xeroinfinity]

You need that DTC to properly diagnose your problems.

I'd almost bet it was a P1810, P1815 .
Here is a TSB on this problem.

09-26-2003, 11:06 AM
#03-07-30-021 Neutral Flare and/or RPM Flare While In Drive, No 1-2 Upshift, SES

Neutral Flare and/or RPM Flare While In Drive, No 1-2 Upshift, Service Engine Soon (SES) Light Illuminated, Diagnostic Trouble Codes (DTCs) P1810, P1815 Set (Replace TFP Manual Valve Position Switch) #03-07-30-021 - (05/15/2003)
Neutral Flare and/or RPM Flare While In Drive, No 1-2 Upshift, Service Engine Soon (SES) Light Illuminated, Diagnostic Trouble Codes (DTCs) P1810, DTC P1815 Set (Replace Transmission Fluid Pressure (TFP) Manual Valve Position Switch)

1995-2003 Chevrolet Cavalier
1997-2003 Chevrolet Malibu
1999-2003 Oldsmobile Alero
1995-2003 Pontiac Sunfire
1998-2003 Pontiac Grand Am
with 4T40E Transmission (RPO MN4) or 4T45E Transmission (RPO MN5)
Condition
Some customers may comment on a neutral flare and/or RPM increase while in drive or no 1-2 upshift and/or the Service Engine Soon (SES) telltale may be illuminated. On 1995-2002 model vehicles, the Powertrain Control Module (PCM) may set a DTC P1810 while on 2003 model vehicles, the PCM may set a DTC P1815.

Cause
The cause may be the transmission fluid pressure (TFP) switch (also known as the pressure switch manifold (PSM)). It will be referred to as the TFP switch in this bulletin.

Correction
Follow the diagnosis and service procedure below to correct this condition.

Perform the following diagnostics to correctly repair this condition
For diagnosis of DTC P1810, refer to DTC P1810 (SI Document ID #854362).
For diagnosis of DTC P1815, refer to DTC P1815 (SI Document ID #854374).

Important
Before installing the new TFP switch, inspect the date code stamped in the switch. The date code MUST BE 2308 or higher. Refer to the illustration above.


Replace the TFP switch. Refer to Transmission Fluid Pressure (TFP) Manual Valve Position Switch Replacement (SI Document ID #803989).
Clear the code and road test the vehicle.
Parts Information
Part Number
Description
Qty

24226580
Switch, Transmission Fluid Pressure (TFP) 1


And welcome to AF jjthornt.