Repair 7

How to Reset the Computer on a 1997 Volkswagen Passat

When it comes to resetting computers, many people believe that you can simply disconnect the vehicles battery and the computer will be automatically reset. This, however, is not the case with modern vehicles and computer systems, including the 1997 Volkswagen Passat. In these vehicles, the engine control unit, or ECU, has an internal battery that maintains memory power to keep track of all the settings, trouble codes, and other data. The proper way to reset the computer is to clear all of the trouble code data from its memory with a scan tool or code reader.

Instructions

1

Shut down the engine, but leave the ignition switch in the ON position. If you turn the ignition switch completely off, the scan tool will not be able to communicate with ECU.

2

Locate the data link connector, or DLC, under the dashboard near the hood-release latch. Plug the open end of the scan tools cable into the DLC. Make sure that it is completely seated so it doesnt come loose in the middle of clearing the codes.

3

Turn on your scan tool and enter any information that it asks for. Typically, youll need to enter the year, make, model, transmission type, and engine size of your vehicle.

4

Use the menu keys to navigate to the diagnostic trouble code, or DTC menu. Each scan tool, depending upon its manufacturer, has a different menu layout. You DTC menu may be called something like Codes or Trouble Codes. Either way, the idea is the same.

5

Choose the option to erase the trouble codes from the ECUs memory. Select Yes or OK if the scan tool asks you if youre sure you want to clear the codes. Most scan tools will ask you this to avoid accidentally clearing the diagnostic data. Disconnect the scan tool once the screen confirms the codes have been erased and the computer is reset.