1. Incorrect Transmission Fluid Level: Check the transmission fluid level and ensure it's at the appropriate level. If it's low, add the recommended transmission fluid.
2. Faulty Shift Solenoid: A faulty shift solenoid can prevent the transmission from shifting into regular drive. Have the solenoid tested and replaced if necessary.
3. Transmission Control Module (TCM) Issue: The TCM controls the shifting of the transmission. A faulty TCM can cause incorrect shifting or prevent the transmission from shifting into regular drive. Have the TCM diagnosed and replaced if necessary.
4. Mechanical Problem: There may be a mechanical problem within the transmission, such as a worn-out clutch or a damaged gear. This will require a professional transmission repair.
5. Faulty Wiring: Check the wiring harness for any damaged or loose connections that may affect the transmission's operation.
It's recommended to have your vehicle inspected by a qualified mechanic to accurately diagnose the issue and determine the necessary repairs.
