The OBDII Scan Tool is designed to work on all OBDII compliant vehicles. All 1996 and newer vehicles (cars, light trucks and SUVs) sold in the United States are OBDII compliant.  One of the most exciting improvements in the automobile industry was the addition of on-board diagnostics (OBD) on vehicles, or in more basic terms, the computer that activates the vehicle's "CHECK ENGINE" light. OBDI was designed to monitor manu-facturer-specific systems on vehicles builtfrom 1981 to 1995. Then came the develop-ment of OBDII, which is on all 1996 cars and light trucks sold in the U. S. Like its predecessor, OBDII was adopted as part of a government mandate to lower vehicle emissions. But what makes OBDII unique is its universal application for all late model cars and trucks domestic and import. This sophisticated program in the vehicle's main computer system is designed to detect failures in a range of systems, and can be accessed through a universal OBDII port, which is usually found under the dashboard. for all OBD systems, if a problem is found, the computer turns on the "CHECK ENGINE" light to warn the driver, and sets a Diagnostic Trouble Code (DTC) to identify where the problem occurred. A special diagnostic tool, such as the OBDII Scan Tool, is required to retrieve these codes, which consumers and professionals use as a starting point for repairs.