DLC Scan Tools

DLC SCAN TOOLS
The ECM can communicate a variety of information through the data link connector (DLC). This data is transmitted at a high-frequency which requires a Scan tool for interpretation. There are several Scan tools available for reading this information.

With an understanding of the data which the tool displays and knowledge of the circuits involved, the tool can be very useful in obtaining information which would be more difficult or impossible to obtain with other equipment.

Scan tools do not make the use of diagnostic charts unnecessary, nor can they indicate exactly where a problem is in a particular circuit. Trouble code diagnostic charts incorporate diagnostic procedures using a Scan tool where possible and most charts require the use of a Scan tool when it is applicable.

The Scan tool has the ability to save time in diagnosis and prevent the replacement of good parts. The key to using the Scan tool successfully for diagnosis Ties in the technician's ability to understand the system being diagnosed, as well as an understanding of the operation and limitations of the Scan tool. The technician should read the tool manufacturer's operating manual to become familiar with the tool operation.

READING DIAGNOSTIC TROUBLE CODES
The provision for communicating with the ECM is the data link connector (DLC) which is located under the instrument panel. It is used to retrieve DTCs, failure record information, live data parameters and ECM reprogramming.

The diagnostic trouble code(s) stored in ECM memory can be read only through a hand-held diagnostic Scan tool plugged in the DLC connector when the ignition is turned On.