Today I'm comparing 3 affordable OBD II code readers that all sell for under $40 on Amazon.
To check out each of these unit's code reading abilities, I first disconnected the intake air temperature sensor on the air cleaner box of my 2008 RAV4. This didn't seem to affect the engine at all, but it did set a error code in the OBD system. Then I disconnected the MAF sensor at the back of the air cleaner box. The engine immediately died and the check engine light came on. I managed to start it again but with the sensor disconnected it wanted to die unless I pushed a little on the accelerator pedal. The error codes were now set, and could be read with the ignition on whether the engine was running or not. To check out the live display data, however, the engine needs to be running.
At first glance, these code readers look very much alike--they are all about the same size, packaged the same, and all three sell for the same price. However, looking deeper shows some significant differences. Of course these readers have a lot of features in common. They can all read current, pending, and historic codes and show a brief definition of each code. They can read live data, which means you can monitor specific sensors in real time, such as oxygen sensor voltages, temperatures, engine RPM's and vehicle speed. They also display freeze frame data, which shows what each sensor was reading when the code was first triggered. Various data about the vehicle and VIN can be read, as well as some manufacturer specific codes.
So let's take a look at each one.
The first is the Ancel AD310 code reader which has a 2 1/4 inch B&W screen, 4 buttons, and a mini USB port at the bottom, but no USB cable is included nor is the port even mentioned in the manual. The OBD cable is 36 inches long.
Next up is the Autel AutoLink AL319 which features a 2 inch TFT color screen, audio tone, color coded lights and a mini USB port. A USB cable is included as well as a user manual and "Maxi-Link II" CD-ROM disc. The unit is internet upgradeable. The OBD cable is 24 inches long.
Finally, we have the Topdon ArtiLink 201 which sports a 2 inch TFT color screen, audio tone, 5 buttons, color coded lights, as well as a mini USB port at the bottom. A brief quick user guide is included. The OBD cable is 42 inches in length.
Now to test each reader.
The Ancel AD310 unit is a basic entry level code reader. It's buttons are rubber and very soft. There is very little button feedback and sometimes the scroll down needs to be pushed harder to register. The monochrome display is backlit and very easy to read. Although it comes equipped with a mini USB port, no cable is included. Just out of curiosity, I plugged a mini USB cable into the unit and connected it to one of my laptop's USB ports. It then displayed a "ready for update" screen, unfortunately, no downloadable update files were listed for the AD310 on the Ancel website.
So I plugged in the Ancel AD310 and it connected to the vehicle.
The main menu lists Diagnostics, where the codes are read, Language which defaults to English, Contrast where you can change the contrast of the screen, and Unit of Measure which changes from Metric to English displays.
Choosing Diagnostics takes you to this menu:
Where clicking on Read Codes shows each code on a separate screen with a brief definition:
Selecting Live Data from the menu will display several screens showing readings from various sensors and inputs in real time. For many of these the engine needs to be running:
On the plus side, the Ancel unit is small, responsive, and quick to connect to the vehicle. I found it simple to use and effective for reading/clearing codes and diagnosing problems. On the negative side I found the buttons mushy with no tactile or audio feedback. The screen is monochrome, and the design seems outdated.
The Autel AutoLink AL319 sports 3 buttons, Enter/Exit, Scroll, and a dedicated I/M button for quick state emmissions readiness testing. The buttons are a membrane type with a nice click and beep for feedback. The beep is fairly loud and can be turned off in the menu. Unlike the others, the Autel only has a scroll down button, no scroll up. This can be inconvenient when you have to scroll down to the end of a long list to get to the "Previous Menu" entry. It has green, yellow, and red indicators on the front panel. Of the 3 code readers, the Autel's "blister pack" was the hardest to open requiring scissors or a utility knife. The others were not welded at the edges making them easier to open and allowing the reader to be stored in the pack.
The main menu sports a graphical color display with icons for Diagnostics (OBDII/EOBD), I/M Readiness (Ready Test), Setup, and About which shows details about the device such as firmware version.
Choosing Ready Test from the menu does the same thing as pressing the I/M button--it opens the I/M Readiness screen. The screen shows how many codes and pending codes are set as well as go/no go checkmarks for various systems. A red exclamation point shows this vehicle has codes that will prevent it from passing emissions tests. When the codes are gone, the green arrow will light up indicating the vehicle is ready for testing.
To read and clear codes, choose the little Check Engine on the main menu. From the Diagnostic menu you can read codes, erase codes, view Live Data, view Freeze Frame data, I/M Readiness, and Vehicle Info.
The unit displays each code on a separate screen. Here we see the MAF code and the intake temperature sensor code on the next screen:
Freeze Frame data and Live Data display in the same way:
The Autel works well, is very easy to use, and is the smallest of the three. The membrane keys have a nice tactile click, and a beep tone with each key press. The dedicated I/M button gives a quick go/no go check for vehicle inspection readiness. The unit comes with a mini USB cable as well as software to upgrade the firmware. The Autel web site has downloadable upgrade files and documentation. The only cons on this unit are the fact that there is only a scroll down button as mentioned earlier, and it has the shortest OBD cord of the three. Other than that it's a great code reader.
The last entry in our review is the Topdon ArtiLink 201 code reader. It has the most buttons (5) out of these code readers. The dedicated I/M button and lighted Y and N indicators are handy for quick readiness testing. The buttons are rubber like the Ancel, but these buttons have a nice tactile click and soft audio beep. One negative for this reader is the lack of a good instruction manual. I found no user documentation at the Topdon website, and there are still features I'm not sure how to use.
Choosing Setup from the main menu allows you to change Language, Unit of Measure, and Beeper. The default language is English, and I didn't change it. Unlike the others, Unit of Measure allows you to change each individual measurement from Metric to English. If for some reason you wanted Speed to show as km/h and distance as miles, you can do that. The Beeper setting allows you to turn on or off the beeper. It's pretty quiet and unobtrusive, so I left it on.
Plugging the Topdon into the OBD port, it shows the menu but of course will not connect until the ignition is on. I then clicked on the OBDII/EOBD icon and chose Read Codes from the menu. From there I chose Current DTC's. Both codes were read immediately, each displayed on a separate screen.
When pressing the I/M button or choosing Ready Test from the main menu, the I/M Readiness screen will be displayed along with either a green Y or red N depending on the vehicle status:
Now for the big difference in the Topdon compared to the others. Of course it can read live data in the Datastream mode:
But it can also plot many of these data points in real time with an on screen graphics chart:
There are some 47 different parameters that can be graphed in this way including all Short Term and Long Term Fuel Trims for banks 1-4, temperature of engine coolant, intake air, and cat converter, barometric pressure, MAF air rate, oxygen sensor voltages, engine RPM, vehicle speed, and absolute throttle position. The graph gives an instant visual feedback which helps troubleshooting some of these problems immensely. For example, if you think one of the sensors is intermittently malfunctioning, you can have a helper drive while you look at the graph for that sensor. If and when the signal drops out, you will see it instantly.
In conclusion, all 3 of these code readers are well-made, sturdy, and easy to use. I only wish they each came with a little zipper case for storing the reader and USB cable. If I were looking for a $40 code reader and had to choose between these 3, the Topdon ArtiLink 201 would be the clear choice. You get more bang from your buck with this unit. It has more features and versatility than the others but the clincher for me is the Datastream graphing mode. I don't know of any other code readers in the price range that can do what this Topdon can. My second choice would be the Autel simply because of the color screen and dedicated I/M button. The Ancel comes in third because it looks like a tester from 1997, not 2017. But I'm sure it's a tried and true proven design.
So that's it. I hope my little review helps when choosing a good code reader. In my opinion, everyone who owns a 1996 or later car needs to have one of these in the glove box or trunk. Even if you don't do your own repair work, the reader can at least get you in the ballpark as to what might be wrong with your car. That way, when you take it to the shop you will at least have enough information to prevent getting taken advantage of. Finally, remember to do your research before buying--just because some code readers look similar and are priced the same doesn't mean they are the same.