Data Link Connector - Serial Data

SCAN TOOL AND SERIAL DATA
The Engine Control Module (ECM) can communicate a variety of information through data link connector terminal "2". This data is referred to as "Serial Data" and 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.

DATA VALUES
With a scan-tool connected and the engine running, certain data parameters can be monitored without changing the engine operating characteristics. These data values can be read and recorded for comparison with the average values for a normally operating system. Comparing actual data values with typical normal values for the same system can aid diagnosis.

Note: The parameters capable of being read vary with engine families. For a description of the data parameters used for diagnosis, see "Typical Scan Data Values". Scan Tool Testing and Procedures
Only the parameters listed are used for diagnosis. If a scan tool reads other parameters, the values are not recommended by Honda for diagnostic use.

A SCAN TOOL THAT DISPLAYS FAULTY DATA SHOULD NOT BE USED AND THE PROBLEM SHOULD BE REPORTED TO THE TOOL MANUFACTURER. THE USE OF A FAULTY SCAN TOOL CAN RESULT IN MIS-DIAGNOSIS AND UNNECESSARY PARTS REPLACEMENT.