How to Reset a Jetta Transmissionby Kyle Sanstrom
The transmission in a Volkswagen Jetta contains a large number of electronic components. These components are controlled by a stand-alone computer called the transmission control unit, or TCU. When the TCU senses a problem with the transmission, it stores a diagnostic trouble code, or DTC, in its memory. It also illuminates the "Service Vehicle" light on the dashboard. Clearing the DTC from the TCU's memory resets the transmission and turns off the "Service Vehicle" light on the dashboard.
Shift the Jetta's transmission into park or first gear (on a manual) and turn off the engine. Turn the ignition switch to the "ON" position.
Connect the data cable of an automotive scan tool to the Jetta's 16-pin diagnostic data port, located underneath the dashboard on the driver's side of the vehicle. Power on the scan tool.
Use the arrow keys on the scan tool's main menu to navigate between menu options. Choose "TCU" from the main menu.
Select "Clear all current and stored DTCs" from the TCU menu. Wait while the scan tool clears the codes. Disconnect the scan tool from the vehicle and start the engine. Confirm that the "Service Vehicle" light is not on. If the "Service Vehicle" light is off, the transmission has been reset.
- Automotive scan tools are extremely versatile. They are small, portable computers that hook up to cars and trucks and run diagnostic tests, gather information and reset computer modules. You can purchase a scan tool from your local auto parts stores and other stores that sell automotive-related tools.