Common Causes of Transmission Problems
If your car won’t move in drive but will in reverse, one of the primary culprits is likely the transmission. An automatic transmission’s functionality hinges on many components, and a failure in these systems often results in the car only moving backward. A thorough inspection of the vehicle’s transmission can reveal if it is at fault.

Key Issues to Look For
Several issues can lead to this specific transmission problem. Firstly, a low level of transmission fluid can hinder the performance of the gears. It’s advisable to check the fluid levels when the engine is hot and the car is in neutral.
Another common issue is a cracked fluid tube, especially earlier models like the 2007 Chevy Cobalt. When the forward tube becomes damaged, it can lead to the transmission only operating in reverse.
Additionally, a faulty speed sensor can cause the system to misinterpret vehicle speed, resulting in difficulties during gear shifts.
Other Factors Affecting Forward Motion
Beyond transmission-specific issues, other factors may be causing your car to move in reverse but not drive. For instance, a sensing problem in the air-fuel ratio can lead to inefficient engine performance, potentially affecting acceleration. Likewise, a malfunctioning engine control unit (ECU) may prevent your vehicle from engaging in drive mode.
If you experience symptoms like irregular shifting, reduced fuel efficiency, or dashboard warning lights, it’s essential to consult a professional mechanic. They can diagnose the issues that may cause your vehicle to only reverse rather than move forward.