General Information

SCAN TOOL
The underdash data link connector allows access to a variety of computer sensor circuit information, using several types of aftermarket scanners. Understanding the function of the scan tool can be useful in obtaining information that might otherwise prove time consuming or impossible to obtain using other test methods. A Scan-tool can be used to display diagnostic trouble codes, and other data stored in the ECM, and can also display the value of input signals and status of certain outputs. Refer to manufacturers instructions for the particular tool being used.

DATA DEFINITIONS
The scan-tool data definitions describe the tools display for the different selector positions, including what units of measurement are being displayed and the range of possible values for each display. This information will assist in tracking down emission or driveability problems, since the displays can be viewed while the vehicle is being driven. See the "Scan Data Definitions" for additional information. Scan Tool Data Definitions

TYPICAL SCAN DATA VALUES
This is a list of signals that can be monitored by a scan tool, describing units of measurement along with the average normal operating range for each displayed value. See "Normal Scan Data Values". Typical Scan Tool Data Values