How To Diagnose? (including below signs but not limited)
1, Check Engine Light on.
2, Abrupt grinding noise, and strange burning smells.
3, Erratically Shift back and forth or get stuck, or refuse to downshift/reverse.
4, Leaking Transmission Fluid, caused by a loose transmission pan or worn gasket, seals.
5, Decline in Fuel Efficiency, the car won't move as quick as the engine is running, more oil consumption than before.

*These issues may suggest that some parts are in need of replacing, and it's better to have the transmission system inspected carefully.*

Fitment & Compatibility
4T65E Master Shift EPC TCC & PWM Downshift Solenoid Manifold Pressure Switch

For Buick LaCrosse 2005-2009
For Buick LeSabre 2003-2005
For Buick Lucerne 2006-2011
For Buick Rendezvous 2003-2007
For Buick Terraza 2005-2007

For Chevrolet Impala 2003-2010
For Chevrolet Monte Carlo 2003-2007
For Chevrolet Venture 2003-2005

For Pontiac Aztek 2003-2005
For Pontiac Bonneville 2003-2005
For Pontiac G6 2006-2009
For Pontiac Grand Prix 2003-2008
For Pontiac Montana 2003-2006

For Oldsmobile Silhouette 2003-2004

Replaces Part Numbers:

Shift Solenoids(1-2&3-4): 10478124 / 24219819
EPC Solenoid: 24225825
Manifold Pressure Switch: 24216426
TCC & PWM Downshift Solenoid: 24212690 / 24227792 / 8683187

The EPC Solenoid appearance is not the same as the OEM, but the function is the same.

*Please check the fitment on the upper left to make sure it fits your vehicle.*