Your automatic VTEC Honda Civic won't travel over 25 miles-per-hour and you are left wondering why. VTEC is a Honda innovation that stands for variable valve timing and electronic lift control, and has nothing to do with the problem at hand. Most Civic owners will blame the transmission, call a mechanic and pay thousands for their transmission to be overhauled or replaced. Try troubleshooting less obvious and more cost effective problems before blaming a wrecked transmission.
Check the automatic shifter to see if it is in drive. If the shifter is in a low gear position, below the letter D on the shifter, the vehicle will have a more difficult time getting to speed.
Check the transmission fluid level by using the red-capped dip stick in the engine compartment. Fill the transmission with automatic transmission fluid if it's needed. Without fluid, the transmission will limit the vehicle's ability to shift into higher gears.
Open the engine compartment and look on the firewall behind the engine block of the driver's side. The fuel filter will be a black metal cylinder with copper washers just under the master brake cylinder. Replace a clogged fuel filter that is limiting the vehicle's performance.
Check the ECM to see if the vehicle is in "Limp mode." The ECM is the computer brain of the Civic and is next to the battery in the engine compartment. The ECM may have malfunctioned and put the vehicle into this emergency operation mode; it does not allow the vehicle to use multiple gears, so the driver may "Limp" it to service. You can remove the ECM with a 10-millimeter socket wrench, but it must go to a professional for diagnostics.
Replace the speed sensor on top of the transmission. The speed sensor is a small black plastic plug on top of the transmission that releases with the help of a 10-millimeter socket wrench. The sensor is a small electronic component that relays information from the transmission to the ECM.
Smell the engine after driving it for approximately five minutes. If the engine smells like it is burning, the gears may be slipping and a transmission overhaul is in order. The gears produce a lot of heat when they slip, and give off a burning smell.
