Car Scanner ELM OBD2

Review by eFreeware

Car Scanner ELM OBD2 is a free Android app from CAR SCANNER LLC that turns a phone into a window onto a car's engine management system. It sits in the Auto & Vehicles category and has been on Google Play since early 2018, with more than 10 million installs and a 4.7 average from over 363,000 ratings. Those are the numbers of a tool that has settled into a routine for a lot of drivers rather than a novelty.

The reason to consider it is straightforward. With an ELM327-compatible adapter plugged into the car's diagnostic socket, the app reads live sensor values, pulls fault codes, and can clear them, which is the sort of job a workshop charges for. The app is free to download, carries ads and offers in-app purchases, and the developer pitches it as offering the widest set of features you will find at no cost on the store.

What follows is a look at what the app does, what hardware it needs, and who I think will get the most from it.

A dashboard you build yourself

The center of the app is a dashboard you arrange to suit yourself. You choose which gauges and charts appear and where they sit, so a driver watching coolant temperature on a long climb can set up something different from someone tracking fuel trims. There is a screen that gathers all the sensors together when you want a single overview rather than a handful of dials.

A HUD mode projects the data onto the windshield, which is the sort of feature that sounds gimmicky until you think about keeping your eyes closer to the road while a reading updates. Whether it works well depends on the car and the light, but the option is there and it costs nothing to try.

The dashboard is also where the app's flexibility shows. Because the layout is yours, the same install can serve as a simple trip display or as a dense instrument panel, and you can change your mind later without changing apps.

Fault codes, freeze frames and emissions checks

Diagnostics are the other half of the job. The app reads and resets DTC fault codes the way a dedicated scan tool does, and it carries a large database of code descriptions so you have something to work with beyond a number. When a fault is stored, the app can also show freeze-frame data, the sensor readings captured at the moment the problem was recorded, which is often more useful than the code alone.

Mode 06 reports ECU self-test results. That is the kind of information that helps you decide whether a problem is worth a workshop visit or can wait, and the developer frames the whole diagnostic side as a way to keep repair costs down.

There is also a readiness check for emissions testing, so you can see whether the car's monitors have completed their cycles before you turn up for a test. For anyone who has ever failed on a technicality rather than an actual fault, that is a small feature with real value.

Beyond the basics: profiles, PIDs and coding

Extended PIDs let you pull information the manufacturer did not put on the instrument panel. The app supports adding custom PIDs, so the data available to you is not limited to the standard set. The developer also includes connection profiles for a long list of brands, among them Toyota, Mitsubishi, GM, Opel, Vauxhall, Chevrolet, Nissan, Infiniti, Renault, Hyundai, Kia, Mazda, Ford, Subaru, Dacia, Volkswagen, Skoda, Seat and Audi, which can open up extra features on those cars.

Coding goes further still, changing hidden settings on supported vehicles. The developer lists VAG group cars on the MQB, PQ26 and MLB-EVO platforms, Toyota and Lexus models with a CAN bus from roughly 2008 onward, and some Renault and Dacia cars, with several service functions available on other makes. Examples given include video in motion, MirrorLink in motion, traffic jam assist activation, a drive mode profiles editor and ambient light configuration.

That is a serious capability, though compatibility can depend on the modules and firmware in a particular car. Treat the coding features as something to research against your own vehicle before you plan around them.

On the performance side, the app times acceleration runs such as 0-60 and 0-100, and it works as a trip computer with fuel consumption statistics. Those two uses pull in a different audience from the fault-code crowd, and they are the reason a single app can appeal to both a home mechanic and a driver who simply likes numbers.

What you need before any of this works

None of it functions without hardware. The app requires a Wi-Fi, Bluetooth or Bluetooth LE ELM327-compatible OBD2 adapter, a small device that plugs into the diagnostic socket and gives the phone access to the car. The developer recommends brands including OBDLink, Kiwi 3, V-Gate, Carista, LELink and Veepeak.

The app works with vehicles using the OBD2 standard, which covers most cars built after 2000 and can reach back as far as 1996 in some cases. The detail sits on the developer's own site. It also states plainly that ECUs differ in how many sensors they expose, so the app cannot display something the car does not provide. That is a limit of the vehicle, not the software, but it shapes what you will see.

Adapters are where the warnings get blunt. Cheap clones, particularly ones marked as version 2.1, are supported but carry bugs. Some can fail to connect to the phone or the car, drop the connection, add lag when reading data, and in some cases make the engine run unevenly. Spending a little more on a known brand is the sensible move, and it is the one piece of advice I would underline before you download anything.

Who gets real use out of it

This is a tool for drivers who want to know what their car is doing and are willing to buy an adapter to find out. If you own an older car, plan to keep it, and would rather understand a warning light before you book it in, the combination of fault codes, freeze frames and sensor readouts is exactly the information you need. The same goes for anyone doing their own maintenance who wants a second opinion before replacing a part.

Enthusiasts with a supported VAG, Toyota or Lexus model have the most to explore, since coding and the brand-specific profiles are where the app goes beyond a generic scanner. Drivers with a newer or less common car will still get the standard diagnostic and trip-computer functions, but the deeper features may not apply to them.

The free price, with ads and in-app purchases present, lowers the barrier to trying it, provided you already have or intend to buy a compatible adapter. Without one, the app has nothing to talk to.

A capable scanner if you supply the hardware

Car Scanner ELM OBD2 earns its 4.7 average by doing a lot for nothing. Live sensor data, a customizable dashboard, fault code reading and clearing, freeze frames, Mode 06 results, emissions readiness, acceleration timing and fuel statistics cover the ground most drivers care about, and the coding features on supported cars push it well past a basic reader.

The conditions are clear. You need a compatible ELM327 adapter, ideally a genuine one rather than a cheap clone, and your car determines how much data there is to see. On supported VAG, Toyota and Lexus models the app is at its most interesting; elsewhere it is a competent diagnostic and trip tool.

If you own an adapter or are ready to buy one, this is an easy install to justify. It suits drivers who already have an OBD2 adapter and want deep diagnostic data from the car's own sensors.

What's new in version 2.1.50

Updated connection profiles database. Added USB ELM327 device support. Bugs fixed.