Transmission problem
2005 Pontiac Sunfire 4 cyl Front Wheel Drive Manual 68,900 miles
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When engine is running it is very hard or impossible to shift into any gear. When engine is off it shifts very easily.
We bought the car used and it worked with out any issues. We have had it for about a month.

This is the explanation from GM, but if it's not working, youll need to scan for codes, the actuator may not be functioning correctly. Information Regarding Automatic Transmission Shift Lock Control Function TECHNICAL SERVICE BULLETIN Reference Number(s): 03-07-30-043A, Date of Issue:  May 25, 2006 Related Ref Number(s): 03-07-30-043, 03-07-30-043A ARTICLE BEGINNING SERVICE INFORMATION This bulletin is being issued to better explain how the Automatic Transmission Shift Lock Control (formerly known as Brake Transmission Shift Interlock (BTSI)) feature is intended to operate. Revised wording regarding the shift lock control system began appearing in the Owner Manuals beginning with the 2004 model year. The shift lock control feature was intended to prevent drivers from shifting out of Park with the vehicle running without the brakes applied. However, if the ignition switch is in the Accessory (ACC) position, it may be possible on some vehicles to move the shift lever out of Park WITHOUT first activating the brake. The shift lock control system is ONLY active when the ignition switch is in the RUN or ON position. This means that when the ignition switch is in the RUN or ON position, the shift lever cannot be moved out of the Park position without activating the brake. Some owners may feel that the shift lock control system prevents an unattended child from moving the vehicle. Please stress to owners, as stated in the Owner Manual, that children should NEVER be left unattended in a vehicle, even if the ignition key has been removed from the vehicle. © 2007 Mitchell Repair Information Co., LLC. Affected Model(s): 2007 and Prior Passenger Cars and Trucks (Including Saturn); 2007 and Prior HUMMER H2, H3; 2005-2007 Saab 9-7X; with Automatic Transmission Supercedes: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 03-07-30-043 (Section 07 - Transmission/Transaxle). Page 1 of 1 Information Regarding Automatic Transmission Shift Lock Control Function -2005 Ponti... 9/7/2008 http://www.ondemand5.com/mric/common/asp/printart.aspx