For 1990-2009 cars

The scan tool Low Speed CAN-Bus Config, Mid Speed CAN-Bus Config, and High Speed CAN-Bus Config functions as used to determine which modules are communicating on each buss. Before using these functions, ensure you can communicate with modules on each buss and that no DTCs in the DTC U2105-U2199 range exist. If you can not communicate with any module on a particular buss you must resolve this issue befor using these functions. If you have DTC's in the DTC U2105-U2199 range you can use these functions as an aid to determine what module is no longer communicating on the buss. Some modules may use more than one data link to communicate. Some modules may have multiple communication circuits passing through them without actively communicating on that data link. This function is used to assist in correcting a communication malfunction. For the description and operation of these serial data communication circuits refer to Data Link Communications Description and Operation .