The Actron PocketScan Plus diagnostic tool reads and displays diagnostic trouble codes — it provides the reason the 'check engine' light is on. 
Product: Actron PocketScan Plus Diagnostic Tool, Model# CP9410.
• OBD II PocketScan™ Code Reader For use with OBD II Compliant Vehicles LCD Display - Is a Single Line Display with 8 characters. ERASE Key - Used to Erase Trouble Codes and I/M Monitor status from Vehicle’s Computer Modules and scroll up through screens. • Safety Precautions For safety, read, understand and follow all safety messages and instructions in manual before operating the PocketScan Code Reader. Always refer to and follow safety messages and test procedures provided by manufacturer of vehicle and PocketScan Code Reader.
Signal Words Used: Indicates a possible hazardous situation DANGER. • • Always use caution when working around ignition coil, distributor cap, ignition wires, and spark plugs. Components can produce a High Voltage while engine is running. • Battery acid is caustic. If contacted, rinse with water or neutralize with a mild base (i.e. Baking soda).
If in eyes, flush with water and call a physician immediately. • PocketScan Code Reader Features Read Codes: Reading Diagnostic Trouble Codes allows the PocketScan Code Reader to read the codes from the vehicle’s computer modules. • Diagnostic Trouble Codes: Diagnostic Trouble Codes are used to help determine the cause of a problem or problems with a vehicle. • MIL Conditions: MIL (Malfunction Indicator Lamp) Status displays the state of the vehicles computer module(s). • MIL ON: Indicates that the Malfunction Indicator Lamp on vehicle should be ON indicating a possible emissions problem.
If the MIL Status is ON and the MIL is not illuminated with the engine running, then a problem exists in the MIL circuit. • Inspection / Maintenance Monitors (I/M Monitors): The I/M Monitors (Inspection / Maintenance) function displays a SNAPSHOT of the operations for the Emission System. After a specific amount of drive time (each monitor has specific driving conditions and time required), the computer’s “monitors”.
• Reading Diagnostic Trouble Codes and Data Avoid Cooling Fan! Fan may turn on WARNING during test. 1.Turn Ignition Key to the Off Position. Locate and Plug in Data Link Connector (DLC.) NOTE: The data link connector should be located under the dashboard on the driverside of the vehicle. • NOTE: If diagnostic trouble codes (DTCs) are already being displayed from a previous read operation, press and hold READ/Scr READ/Scr READ/Scr READ/Scroll Do READ/Scr oll Do oll Down oll Do oll Do 6.Observe a Moving on Display.