KARFANS K120: Universal OBD2 Scanner with Battery Monitor Review

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The KARFANS K120 OBD2 scan tool is a new entrant to the world of OBD scanners. It comes packed in a carrying case that doubles up as a storage facility.

KARFANS K120 vs. ANCEL AD410 vs. Bluedriver Comparison Chart

Great for checking the ECU and I/M readiness, the KARFANS K120 still lacks in some aspects. That’s especially true when you consider that it doesn’t access as many systems as other scanners do.

In case you are not entirely sold on this OBD2 code reader, you could consider an alternative. Two of its closest compatriots are the Ancel AD 410 and BlueDriver Bluetooth OBD2 scan tool. While the BlueDriver is a wireless adapter that requires a mobile device and diagnostic app, the Ancel AD 410 connects to the OBD port using a cable like the KARFANS K120.

Here’s how they compare in functionality:

Karfans K120
Karfans K120
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Customer Rating
PriceKarfans K120 priceANCEL AD410 priceBlueDriver price
Product Dimensions2.6" x 0.7" x 5.5"9" x 6.3" x 1.6"2.2" x 1.9" x 1"
Item Weight1.14lbs12oz2.08oz
Compatible with OBD2 carsYesYesYes
Supports CEL/MIL reset and emission TestYesYesYes
Battery monitoringYesN/AN/A
Mode 6N/AN/AYes
Supports ABS, SRS TestsN/AN/AYes
Bottom LineKARFANs K120 OBD2 code reader is perfect for a car owner.ANCEL AD410 is built for any car owners.Useful and well worth the money;
Highly recommend for DIYers and car owners.
If you are wondering what scan tool to buy, this article will help you determine whether the KARFANS K120 is it
This review of the KARFANS K120 helps you decide whether this OBD2 scanner is suitable for your needs

KARFANS K120 Overview

karfans review
KARFANS K120 (Universal) OBD II Scanner with Battery Monitor Diagnostic Code Reader
the KARFANS K120 supports USB connectivity. You can plug it into a computer and update the software for free. Unfortunately, you can’t use it on a Mac system.

The KARFANS K120 supports USB connectivity. You can plug it into a computer and update the software for free. Unfortunately, you can’t use it on a Mac system.

Obviously, that’s a noble idea on the manufacturer’s part, especially for those looking to purchase a portable OBD2 code reader. It weighs just over one pound and can easily fit in your hand. Even if you’re not planning to keep it somewhere in the driver’s compartment, you certainly won’t tire carrying it around. Inside the case are a USB cable and a user manual.

Overall, it’s safe to say that the package of KARFANS K120 is nice. But as you probably already know, packaging should be the least of your worries. The usefulness of an OBD2 code reader entirely depends on its compatibility and functionality.

Detailed Review of KARFANS K120


This scanner is basically designed for OBD2-compliant vehicles that are made and sold in the US. Just in case you need clarification, OBD2 cars are those manufactured post-1995. They have a 16-pin connector where an OBD2 scan tool plugs into. So if made in 1995 or earlier, your car doesn’t work with this scan tool.

Also, it doesn’t work on all OBD2 vehicles. The car you’re trying to check should not be more than 12V. Meaning its compatibility is limited to cars and light trucks only.

On a positive note, it covers virtually all 12V models, including gas, diesel, and hybrid cars.

Most other tools of its price and functional range rarely cover diesel engines and rarely support hybrids. So that’s a plus for those who drive diesel vehicles and hybrids.

As long as we are talking compatibility, the KARFANS K120 supports USB connectivity. You can plug it into a computer and update the software for free. Unfortunately, you can’t use it on a Mac system.

Features and Functionality

Diagnostic Trouble Codes

As an OBD2 code reader, the KARFANS K120 can read and erase fault codes. It does so for the engine control unit (ECU) codes. Simply said, this device can pull and clear engine codes. Those codes usually trigger the Check Engine Light (CEL) or the Malfunction Indicator Lamp (MIL). After pulling the codes, you can go ahead and fix the associated problem. Once that is done, the KARFANS K120 will then clear that code, and the CEL/MIL will turn off.

One of the best things about using the KARFANS K120 as an engine code reader is that it has a lookup library.

Every code comes with a description to help you understand the problem. That allows you to judge whether it needs professional attention or something you can sort the DIY way. Either way, you won’t have to spend time and money visiting the shop just to get an engine diagnostic scan.

However, this device falls short in a very big way. It only scans the engine and no other system beyond that. You can’t use it for SRS, ABS, transmission, and other system diagnostics. So if you’re looking for a full system scanner, this one will disappoint.

Emission Tests

Built with an I/M hotkey, the KARFANS K120 allows you to check your vehicle for emissions readiness and drive cycle verification. It probes the various emission-related systems, including the EVAP canister, separator, and gas tank, to ensure that they are working as they should. So what does that mean? It means this device will tell you whether your car is ready for emissions inspection.

You will know if you will pass your local and federal smog tests without visiting the shop. That should save you some time and money that you would have spent at the shop.

While basic I/M readiness checks are excellent, Mode 6 and Mode 8 tests are even better. However, KARFANS don’t state if this device supports both (or any).

Mode 6 is essential in some situations because it pinpoints all sorts of emission-related problems, including those that haven’t triggered a code or affected emission monitors.

Some people consider misfire count (part of Mode 6) to be essential. If you are one of them, you won’t like how the KARFANS K120 is vague and unclear about its emission check capabilities.

You basically can’t tell whether or not it supports that kind of scan on your vehicle.

Data Stream

It may not access all the onboard systems nor run all emission tests, but for those that it does, this OBD2 code reader does a great job providing real-time data streams and monitoring.

It offers the live engine and emissions data and also reads freeze frame data. You can use the information to pinpoint and fix any engine or emission system problems in your vehicle.

Additionally, the OBD2 scan tool can help track and report battery health.

Who should use it?

This OBD2 code reader is perfect for a car owner. It allows you to identify minor engine problems by yourself.

With it, you will be able to pinpoint an issue before visiting the shop for repair.

Plus, it helps when you need to run emission tests, so overall it’s an excellent product for the ordinary car owner.

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The Bottom Line

Although it performs well in engine diagnostics, you get the feeling that the KARFANS K120 could do more.

The manufacturer could add Mode 6 and Mode 8 tests to compensate for what it lacks in system access. That way, it could have been a device fully dedicated to resetting the MIL and running comprehensive emission tests.

However, it’s quite nice for a tool that costs relatively cheap. Most other devices in its price range won’t offer nearly as many functions as it does. With it, you can feel safer knowing that you can run engine diagnostics and emission checks yourself.

BonusANCEL AD410: Multi-Systems OBD2 I/M Readiness MIL Scan Tool Review

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