Why does your 2000 Hyundai not shift to overdrive?

Your 2000 Hyundai may not shift to overdrive due to several potential issues, such as low Transmission Fluid, a faulty transmission control module, or a malfunctioning sensor. Additionally, problems with the throttle position sensor or issues within the transmission itself could prevent the shift. It's advisable to check the fluid levels and have a mechanic diagnose the issue for a proper repair.