I am often asked "What is the difference between a Scanner and a Code Reader and which one is best for my needs"
The slang term for an Automotive Diagnostic Analyzer is "Scanner" because it will scan the vehicle's ECM (engine control module). There are two basic types, one has diagnostic software and the other does not.
The models with-out diagnostic software are referred to as a code reader or code retriever. For home or personal use a code reader is affordable ($35.00 to $250.00) and some of the units will provide a lot of information. These units will pull fault codes only if the check engine warning light is on. Some of these will provide freeze frames of the sensor readings (Warning light does not have to be on for this feature). If it refreshes the freeze frame automatically, they some times refer to it as "live data". Look for the speed of the refresh rate, the faster the rate, the closer to real time viewing. This can be a helpful feature for intermittent problems.
Look for one that will cover the vehicle you are working with. Models 1983 to 1995 are known as OBD I, most of the code readers will only cover the Domestic vehicles; Ford, General Motors and Chrysler. This is because each vehicle, in this year frame, has a different plug and software program, so most of the code readers will not cover the Asian or European vehicles. You would need a separate reader for each make and model. These Domestic manufactures also have models imported by an Asian company and they may not be covered as well.
Vehicle models 1996 to current year are known as OBD II. This is on all vehicle manufactured for the American market and is a universal system used world wide, with some difference in some countries. In 2008 it was mandatory for all vehicle manufactured for the American market to have C.A.N. (Controlled Area Network)Software. Look for these features if your vehicle falls within the year frames.
When a code reader has given you a fault code, and you replaced the sensor it indicated and the problem or light still exists, a Scanner with diagnostic software is needed. These units cost a lot more money ($1500.00 to $6000.00). These are more for the professional technician or repair shop. They will do everything the code reader will do and the warning light doesn't have to be on. These units usually come with cables for both OBD I and OBD II Asian, European and Domestic vehicles. These units are equipped with software to help direct you through flow charts to determine the real problem.
Some good features to look for in a diagnostic scanner are;
- bi-directional control; meaning they can actuate certain sensors on the vehicle to see what the other sensors will do to compensate.
- Larger coverage on the vehicles like ABS, SRS, Transmission and Body code diagnostics. Some of the code readers are coming with ABS code retrieval but they still have no diagnostic features in that area either.
- PC accessibility is a helpful feature to allow storage of customer vehicle information.
- Updating capabilities - this can get very costly. Some manufactures will not allow you to skip a year, they charge for each year missed, while others will include the catch up at no additional charge.
- How long has the unit been on the market - technology is constantly changing and scanners seem to be discontinued every 4 or 5 years.
Remember when looking for the best deal, make sure you are not losing beneficial features with the price cut. Buying from a company that will be there to support you is a good practice also.