Home: FAQ: Automotive Diagnostic Tools - Questions about Readers & Scanners

What is the difference between a Reader and a Scanner? Readers and Scanners both display vehicle computer fault codes with descriptions. Scanners have the additional function of providing real-time component voltage and current outputs. Some examples of these components are: 02 Sensors, Fuel Injectors, Throttle Position Sensors, and Transmission Sensors. Examples of Code Readers are the Actron CP9125 PocketScan and the AutoXray 2000 EZ-Scan. Examples of Code Scanners are the Actron CP9145 AutoScanner and the AutoXray 4000 EZ-Scan.

What is the difference between OBD I & OBD II (On-Board Diagnostic I & II)? OBD I refers to most domestic cars manufactured 1981 – 1995. Before OBD II was enforced, manufacturers used different data link connectors to communicate with the vehicles.

OBD II covers all passenger cars and light trucks built for sale in the U.S. 1996-present. Any vehicle with a GVW (Gross Vehicle Weight) up to 8,500 has to be OBDII Compliant (California GVW 1400). Any vehicle over the GVW of 8,500 (i.e. Medium/Heavy Duty trucks) may not be compliant - This information can be found on a sticker located on the driver's doorframe.

What are generic OBD II codes? Generic OBD II Diagnostic Trouble Codes are common for any OBD II compliant vehicle, be it Domestic, Asian or European. These codes are sometimes called "P-codes" and typically begin with "P0" or "P2".

What are enhanced OBD II codes? Enhanced OBD II Diagnostic Trouble Codes are unique to a vehicle of a specific year, make, model (and possibly engine size). They are assigned by the vehicle manufacturers to cover situations not already covered by a Generic DTC. These codes typically begin with "P1".

Will these Code Scanners and/or Scan Tools retrieve Anti-Lock Brake or Airbag codes? OTC Products such as the Nemisys and Genisys can be used to retrieve these codes. Most AutoXray and Actron Code Scanners and Readers are designed to retrieve Diagnostic Trouble Codes (DTCs) from the Powertrain controller (engine computer) only. They will not retrieve Anti-Lock Brake (ABS) or Airbag (SRS) codes.

Actron's CP9449 is an ABS Code Reader for Domestic OBDII vehicles.

What about Diesel Engines? Actron tools will do well with the Chrysler and GM Diesel vehicles that are OBDII compliant. There are some issues with the Ford diesels, especially the F-250's and up. AutoXray tools do not do well with diesels of any sort except the smaller import vehicle diesel engines (i.e. VW).

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