* Transmission Problems: This is a very common cause. Issues could include:
* Transmission fluid problems: Low, dirty, or incorrect fluid can prevent proper operation.
* Internal transmission failure: Worn parts, broken gears, or other internal damage can prevent power transfer.
* Broken or slipping clutch (manual transmission): The clutch might not be engaging properly, preventing power from reaching the wheels.
* Faulty torque converter (automatic transmission): The torque converter is responsible for transmitting power from the engine to the transmission. A faulty one won't allow the car to move.
* Shift cable/linkage issues (manual and some automatics): The mechanism that selects gears might be broken or misadjusted.
* Drivetrain Problems: Problems with the components transferring power from the transmission to the wheels.
* Broken driveshaft: A broken or disconnected driveshaft will prevent power from reaching the wheels.
* Differential problems: A damaged differential prevents the wheels from rotating at different speeds, necessary for turning. A completely locked differential might allow starting but no movement.
* Wheel bearings: Severely damaged wheel bearings might seize up, preventing wheel rotation.
* Axle problems: Broken axles prevent power transfer to the affected wheels.
* Parking brake engaged: This is a simple but easily overlooked cause.
* Brakes: In rare cases, a brake issue might prevent movement. This is less likely if the car starts normally, but a severely stuck caliper or emergency brake could still be a factor.
* Computer/Electrical Issues:
* Transmission control module (TCM) problems: The TCM controls the transmission's operation. A faulty TCM can prevent the transmission from shifting.
* Other control module issues: Other computer modules, such as the engine control module (ECM), may also influence transmission function.
Troubleshooting Steps (Do NOT attempt major repairs yourself unless you have significant mechanical experience):
1. Check the obvious: Is the parking brake fully released? Is the gear selector in drive (D) or reverse (R)?
2. Listen for unusual noises: Any grinding, whining, or clicking sounds can indicate a specific problem area.
3. Check transmission fluid level: Low or dirty fluid is a common cause.
4. Check for warning lights: Any illuminated warning lights on the dashboard can point to the source of the issue.
5. Have a mechanic diagnose the problem: This is the safest and most efficient way to identify the exact cause and get your car repaired.
Ignoring the problem can lead to further, more costly damage. It's best to get your car checked by a professional mechanic as soon as possible.
