* Low Transmission Fluid: The most common and least expensive cause. Low fluid can lead to overheating and improper pressure regulation within the transmission. Check your transmission fluid level immediately. If it's low, you'll need to add fluid and then investigate *why* it's low (leak, internal failure). Caution: Adding fluid might only be a temporary fix if there's a serious internal problem.
* Torque Converter Clutch Solenoid or Pressure Control Solenoid: These solenoids control the engagement and disengagement of the torque converter. Failure can cause the transmission to slip or not engage properly, particularly when under load (higher RPMs). These are relatively inexpensive components to replace.
* Transmission Valve Body Problems: The valve body contains numerous valves and passages that regulate transmission fluid pressure. Worn or damaged valves can cause a variety of issues, including the symptoms you describe. Repairing or replacing the valve body is more involved and costly.
* Internal Transmission Damage: This is the worst-case scenario. Worn clutches, bands, or other internal components can cause pressure issues and lead to transmission failure. This often requires a rebuild or replacement of the entire transmission, which is the most expensive option.
What to do:
1. Check the transmission fluid: This is the absolute first step. Check the level and condition of the fluid (it should be pink or red and clear, not brown or burnt smelling). If it's low, add fluid (the correct type for your transmission – check your owner's manual) and see if the problem improves. This is a *temporary* measure.
2. Have a mechanic diagnose the problem: This is crucial. A professional mechanic can properly diagnose the cause of the transmission failure. They will likely perform a scan to check for trouble codes and inspect the transmission fluid and pressure.
3. Avoid driving the car excessively: Continuing to drive the car with this problem could cause further damage to the transmission.
Don't delay: Transmission problems tend to worsen quickly. The longer you wait, the more extensive and costly the repairs will become.
