It’s a frustrating experience⁚ your car’s engine roars, the transmission shifts into gear, but the vehicle remains stubbornly stationary. This can be a symptom of various issues related to your automatic transmission. Here’s a breakdown of common culprits and how to diagnose them⁚
1. Low Transmission Fluid
The first and easiest culprit is low transmission fluid. This fluid lubricates the transmission’s internal components and helps transfer power. If the level is too low, the transmission may not be able to engage properly.
- Check the dipstick⁚ Most automatic transmissions have a dipstick for checking the fluid level. Make sure the engine is running and the transmission is warmed up before checking.
- Top off if necessary⁚ If the fluid level is low, add the correct type of transmission fluid. Consult your owner’s manual for the recommended fluid.
2. Faulty Transmission Control Module (TCM)
The TCM is the “brain” of the transmission. It receives information from various sensors and controls the shifting process. If the TCM is faulty, it may send incorrect signals, preventing the transmission from engaging properly.
- Diagnostic Trouble Codes (DTCs)⁚ A faulty TCM can trigger DTCs, which can be read by a mechanic using an OBD-II scanner.
- Replacement⁚ If the TCM is faulty, it will need to be replaced. This is a job best left to a professional mechanic.
3. Damaged Torque Converter
The torque converter acts as a fluid coupling between the engine and transmission. It allows the engine to run smoothly while the vehicle is stopped and transfers power to the transmission when you accelerate. A damaged or worn torque converter can prevent the transmission from engaging properly.
- Slipping⁚ A failing torque converter can cause the transmission to slip, making it feel like the car is losing power.
- Replacement⁚ A damaged torque converter usually needs to be replaced. This is a complex repair and should be performed by a qualified mechanic.
4. Mechanical Issues
The transmission itself can have mechanical problems that prevent it from engaging. This could include worn clutches, damaged gears, or a faulty valve body.
- Noises⁚ Mechanical issues within the transmission can often be identified by noises, such as grinding, clunking, or whining sounds.
- Inspection⁚ A mechanic will need to inspect the transmission to diagnose and repair any mechanical problems.
5. Other Potential Issues
Other factors can contribute to a transmission that engages but doesn’t move. This could include⁚
- Stuck Shift Cable⁚ The cable that connects the gear selector to the transmission could be stuck, preventing the transmission from shifting into the correct gear.
- Faulty Solenoids⁚ Solenoids control the flow of fluid within the transmission. A faulty solenoid could prevent the transmission from engaging properly.
- Broken Transmission Input Shaft⁚ The input shaft connects the torque converter to the transmission. A broken input shaft can prevent the transmission from engaging.
Important Notes
- Professional Diagnosis⁚ Diagnosing transmission problems can be challenging. It’s always best to have a qualified mechanic inspect your vehicle and determine the cause of the problem.
- Don’t Drive with a Faulty Transmission⁚ Driving with a faulty transmission can cause further damage, leading to more expensive repairs in the long run.