Updated: Oct 14, 2016

auto code reader

Diagnostic Code Reader and Scan Tools for OBDII Vehicles:

  • What is a diagnostic code reader?
  • Benefits of using an auto code reader
  • How much do OBDII code scanners cost? Which should I buy?

The first thing to clear up is - What is OBDII? It stands for on board diagnostics and the II is for vehicles that are 1996 or newer. If you own a car that was made from 1996 until now, then you are in luck if you want to do some home diagnostic tests on the vehicle. There are devices called diagnostic code readers that work on almost all cars and light trucks made after 1996. The two leading brands that literally dominate this category are Actron and Equus. AutoXray is another top selling manufacturer of these diagnostic tools, but their products don't rate as highly as the other two.

Actron sells many more products that are less than $100 and get excellent reviews while Equus offers more expensive tools that are still top rated by experts and vehicle owners. Which one is right for you? It really depends on what type of information you are looking to get from your cars computer system. Many owners admit they purchased one of these diagnostic code readers right before they had to take their vehicle down for an emissions test. In many states you can't get a smog test (or similar) done if your check engine light is on.

diagnostic code reader


The video below shows the basic functions of an automotive code reader so you know what to expect:



What to look for in an OBD2 Reader?

There are plenty of readings these tools can give you and some maybe offer too much information for what you want. Features to consider are back lit display, detachable cable, USB cable for online updates, on-screen code definitions, battery low indicator, code lookup on tool, record and playback live sensor data, print data, display graphing data, urgency indicators, read codes, pending codes, and erase codes, view freeze frame data, display vehicle information like VIN # and calibration #, view live engine parameters (also referred to as PIDS), have an O2 monitor test, and handle all protocols on current vehicles.

The most basic things like reading the MIL status (malfunction indicator lamp) and I/M readiness monitor status (emissions) should be available on any model you buy. The best OBDII code readers are those that are easy to use and simple enough for a regular car owner to figure out. The Actron CP9125 is certainly one to consider and if you want a more high end model go with the Equus 3130 Innova that costs about $155.

We found dozens of reviews on websites like Amazon.com for all types of tool scanners and code readers and many stood out more than others. Autobarn is another car product website with informed customer feedback on products from Equus and Actron. Other auto scanner reviews can be found on sites like CNET, Youfixcars.com, Allpar.com. From master mechanics to weekend enthusiasts, we stacked up all the reviews for the OBDII diagnostic code readers and came up with some clear winners. You can browse the top selling diagnostic code readers and scanners here.

diagnostic code readers

Best Diagnostic Code Reader for OBDII Vehicles:

RECOMMENDED - The #1 seller on Amazon is the Actron CP9125 PocketScan Diagnostic Code Reader for OBDII (Post-1996) Vehicles which is priced at about $55. This small pocket sized tool will allow you to get detailed information from your vehicle's computer and let you diagnose any problems you may be having. The CP9125 reads trouble codes and the scanner displays them on the small screen. Many people complain about their "check engine light" being on and this tool will help you to turn it back off.

One reason the tool is the most popular on Amazon is because it's easy to use for novices (like me) and for more capable DIY mechanics. The key is being able to decipher the OBD II diagnostic trouble codes (DTCs) on cars and light trucks that are 1996 models and newer. Once you have solved the issue with your car the PocketScan lets the user "clear" any trouble codes and gets your vehicle to turn off the warning lights.

Owners say the software CD that comes with the Actron diagnostic tool is invaluable as their are over 3000 code definitions you can look up and get educated on. Another feature that experts and novices like about this diagnostic code reader is that it's updateable so any vehicle you buy in the future should be able to work with it just fine. You get a 1 year limited warranty with this model. Some of the high end Actron readers offer much more than this budget model. We SUGGEST you browse all the Actron diagnostic vehicle scan tools here to find one that fits your exact budget and needs.

To check out how to use a diagnostic code reader for your vehicle - click the image below to go to video.

odb2 code scanner

Top Rated Diagnostic Code Scanner for OBD II Cars:

RECOMMENDED - The Equus 3130 Innova Diagnostic Code Scanner with Live, Record and Playback Data Capability for OBDII (Post-1996) Vehicles is a very valuable tool to have if your car is giving you "check engine lights". Many owners freely admit they have taken their vehicles down to the local mechanic to get a "service engine" light looked at only to get a bill for $100 and problem fixed within minutes. That's where owning a diagnostic tool like the Equus 3130 can really save you money in the long run.

The 3130 is superior to the Actron listed above as it views, records, and plays back live data as well as has a freeze frame data function. Owners say the built in memory allows you to store codes making it easier to check your vehicles the 2nd and 3rd times if necessary. The all in one screen display and LED display makes for easy reading of all codes and data. Connect it to your PC so you can print or save the diagnostic reports that you generate. "Troubleshooting has never been easier" says an ASE master technician and another owner says it "works great to communicate with both OBD2 and Can Bus vehicles".

The Equus is the best all around code reader we could find and I would agree with one customer who calls it a "money saver". The Equus 3160 Innova is another great option if you want a more professional setup.

readers obd2 equus innova scanner

Budget/Value Car Code Scanner:

The latest tool is the ScanTool 426101 OBDLink MX Bluetooth: OBD Adapter/Diagnostic Scanner for Android & Windows. Why is this one so different? It's because you can hook the device right up to your smartphone and get the codes you need. The software works on all cars made in 1996 and newer. The biggest drawback is that the device doesn't work with Apple IOS products. Yes, that is a big issue given so many iPhone users out there. Android and Window users will appreciate the Scan Tool, but as an Apple user myself, I feel left out. It supports all 5 OBD-II protocols, plus SW-CAN (GM) and MS-CAN (Ford). Hopefully they will create one for Apple users soon.

More videos and resources are here on our Diagnostic Code Scanner Resource Page.

code readers for cars

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