- Transmission Fluid: Check the transmission fluid level and condition. If the fluid is low, add more. If the fluid is dirty or burnt, replace it.
- Transmission Filter: Check the transmission filter and replace it if it is dirty.
- Overdrive Solenoid: The overdrive solenoid is responsible for engaging and disengaging the overdrive gear. If the solenoid is faulty, it can cause the transmission to go into overdrive at inopportune times. Test the solenoid and replace it if necessary.
- Transmission Control Module (TCM): The TCM is the electronic control unit that manages the transmission. If the TCM is faulty, it can cause the transmission to go into overdrive at the wrong time. Have the TCM diagnosed and replaced if necessary.
If you have checked all of these things and the transmission is still going into overdrive, you may need to have the transmission rebuilt or replaced.
