Home ›Comparisons ›ScanMaster-ELM
Diagnost vs ScanMaster-ELM: past generic OBD2, into every module
ScanMaster-ELM is a solid paid Windows tool that covers the OBD-II standard end to end. Diagnost is free and keeps going after the standard runs out, into ABS, airbags and body modules.
People look for a ScanMaster-ELM alternative for one of two reasons. Either they saw the license price and want the same job done for free, or they bought the license, read the engine codes cleanly, and the ABS light is still on. The first reason is about money. The second one is about the ceiling of the OBD-II standard, and it is worth understanding before you buy anything. This comparison uses what each vendor publishes, as of September 2026.
What each one is
ScanMaster-ELM is a Windows program from WGSoft, a German developer, built specifically around the ELM327 chip. Per wgsoft.de, it implements all ten OBD-II diagnostic modes defined in SAE J1979 ($01 through $0A) and all five communication protocols: CAN per ISO 15765-4 at 500 and 250 kbps with 11-bit and 29-bit identifiers, ISO 9141-2, KWP2000, J1850 PWM and J1850 VPW. Any compatible adapter will do over serial, USB, Bluetooth or WiFi. System requirements are Windows 7, 8, 8.1, 10 and 11, 32-bit and 64-bit; the current branch is 6.x and updates inside a purchased version are free. The store on the vendor site shows the license at 59 euro against a regular price of 75 euro as of September 2026, and a free demo is offered for evaluation.
Diagnost is a free Windows 7-11 program, with macOS listed for USB and WiFi adapters. It scans for every adapter you have plugged in or paired - ELM327 over USB, Bluetooth, BLE and WiFi, OBDLink, J2534 devices, K-line cables - and picks the one that is actually on the car. Several can stay connected at once, and unplugging one switches to another without a restart. Generic OBD-II is only the starting point: from there it queries every module it can reach over UDS and KWP standard addressing and over manufacturer addressing for Toyota and Lexus, Nissan and Infiniti, VAG, GM and Opel, Mercedes and Ford. A built-in AI mechanic runs the module sweep itself and explains the result in plain language.
Side by side
| Criterion | ScanMaster-ELM | Diagnost |
|---|---|---|
| Adapters | Any ELM327 or compatible chip: serial, USB, Bluetooth, WiFi. Port picked manually. | ELM327 (USB, BT, BLE, WiFi), OBDLink, J2534, K+DCAN, ENET, KKL. Detected and selected automatically. |
| Cars covered | Any OBD-II or EOBD vehicle, within the limits of the standard. | Any CAN car, roughly 2008 and newer; K-line cars up to about 2005-2007. |
| Modules read | Whatever the standard exposes: powertrain and emissions. | Every reachable module: engine, transmission, ABS and stability control, airbags, body, cluster, climate. |
| Standard OBD-II functions | All ten modes, including freeze frame, readiness monitors and Mode 06. | Codes with plain-language explanations, freeze frame, readiness monitors, live sensors. |
| Coding | None - outside the OBD-II standard. | BMW and Mini only: hidden features by checkbox, with a module backup and automatic rollback. |
| Service functions | None. | BMW: battery registration, service interval reset, adaptations. |
| Live data | Yes, with graphs and logging in the licensed version. | Live sensors, trip recording, interactive graphs. |
| Price and license | 59 euro in the vendor store, regular price 75 euro; updates free inside the version. | Free in full, no car limit, no hardware lock. |
| Operating system | Windows 7-11, 32-bit and 64-bit. | Windows 7-11; macOS listed for USB and WiFi adapters. No Android or iOS. |
| Interface languages | Thirteen languages listed on the vendor site, including German and English. | English and Russian. |
| AI help | None. | Built-in AI mechanic, plus an online chat on the site. |
| Learning curve | You need to know mode numbers, PIDs and how to read the report. | Press Scan and read the summary. |
Where ScanMaster-ELM is stronger
It does one job and does all of it. The full mode set is there with nothing held back, and that includes Mode 06 - on-board monitoring test results, where you can see how much margin is left before a monitor trips, long before a light comes on. Readiness monitors are presented the way an inspection station asks for them. Five protocols mean it will still talk to an early-2000s car on J1850 or ISO 9141-2, not only to modern CAN vehicles.
Behind that sits well over a decade of work on a single product: the interface is plain but predictable, and support and updates come straight from the developer. Thirteen interface languages is more than we offer. If your work is emissions diagnostics on a Windows laptop, nothing in the program is wasted on you.
Why generic OBD-II cannot see your airbag light
This is the single biggest misconception about this class of software, and it is not a ScanMaster-ELM flaw. OBD-II was written as an emissions regulation. It obliges a car to expose emissions-related data through a fixed set of modes: powertrain fault codes, freeze frame, readiness monitors, a defined parameter list. Everything else lives in manufacturer modules, on manufacturer protocols, outside the standard.
That is why you get "no codes found" with a light on
The scan queried the engine controller, which genuinely has no stored fault, while the code sits in the ABS or restraint module. Modes $01 to $0A cannot reach those. You need a request addressed to that specific module over UDS or KWP - which is exactly what Diagnost does once the standard part is finished.
The same logic explains clearing. A standard clear wipes emissions codes in the engine controller; an airbag lamp will not go out, because its fault has to be cleared in its own module. If all you need is engine codes and you would rather not install anything, the in-browser reader talks to an ELM327 over USB or BLE from Chrome or Edge.
Where Diagnost is stronger
- Every module, not just the powertrain. ABS and stability control, airbags, transmission, body, cluster, climate - read, explained and clearable per module.
- Free with nothing withheld. No demo tier, no PID library behind a paywall, no per-car limit. Download it on the program page.
- It finds the adapter for you. No COM port hunting: it probes every interface, identifies the adapter by its ATZ and ATI reply, and uses the one with a car on it.
- Dealer depth on BMW. E chassis 1998-2013 and Mini R50-R56 over K+DCAN, F, G and I chassis over ENET, with coding, service functions and cross-module mileage checks.
- It explains instead of listing. The AI mechanic sweeps the modules, then tells you what is happening and what to check first.
- History by VIN. Sessions are stored and faults compared between visits, so you can see whether a repair actually held.
Which one to pick
Buy ScanMaster-ELM if you want the OBD-II standard implemented completely on Windows, you care about Mode 06 and pre-CAN protocols, and you prefer a paid product with direct vendor support.
Use Diagnost if the warning light is not the check engine light; if there are several cars of different makes in the garage; if you do not want to pay to read fault codes; if you own a BMW and want dealer-level access. Start on the ELM327 software page, which walks through the first scan on a cheap adapter.
Can you run both
Yes. They are separate programs with separate files, and the same adapter serves both - just not at the same time, since one connection holds the port. A sensible split is ScanMaster-ELM for detailed emissions work and Mode 06, Diagnost for the full module sweep and the explanation. Related comparisons: Diagnost vs OBD Auto Doctor for the cross-platform tool in the same class, Diagnost vs Car Scanner and Diagnost vs Torque for the phone apps that use the same ELM327 dongle.
Questions and answers
What does the free ScanMaster-ELM version leave out?
There is no free full edition, only a demo. It exists so you can confirm that your adapter and your car answer before you buy; the license unlocks the rest. WGSoft lists what the demo leaves out on its own product page, so check there for the current demo feature list before assuming a function is included.
Is the ScanMaster-ELM license worth it?
If you work strictly on the emissions side, yes: you get all ten OBD-II modes, all five protocols and direct vendor support for a one-time price. If what you actually want is an ABS or airbag code, no amount of license money changes that, because those codes are outside the OBD-II standard entirely.
Does ScanMaster-ELM read ABS and airbag modules?
No. It implements the OBD-II standard, and the standard only covers emissions-related data from the powertrain. Chassis, body and restraint modules use manufacturer protocols on their own addresses, which is where Diagnost picks up with UDS and KWP requests.
Does ScanMaster-ELM run on Windows 11?
Yes. WGSoft lists Windows 7, 8, 8.1, 10 and 11 in both 32-bit and 64-bit, and the current branch is 6.x. Reports of Windows 11 trouble almost always trace back to old 2.1 builds circulating on download portals, not to the current release.
Is ScanMaster-ELM still updated?
Yes. The vendor site lists 6.x as the newest branch as of September 2026, with updates free inside a purchased version and available from the support area or from inside the program.
Which adapters does each program support?
ScanMaster-ELM works with any ELM327 or compatible chip over serial, USB, Bluetooth or WiFi. Diagnost handles those plus OBDLink STN devices, J2534 pass-through interfaces and K+DCAN, ENET and KKL cables, and it can keep several connected at once.
ScanMaster vs OBD Auto Doctor: which is closer to Diagnost?
Neither, in scope. Both stay inside generic OBD-II; OBD Auto Doctor adds macOS, Linux and phone apps and a free tier, ScanMaster-ELM adds the complete mode set on Windows. Diagnost differs from both by scanning every module and by going to dealer depth on BMW.
How much does Diagnost cost?
Nothing. Every function is free, including all-module scanning, live data, trip recording, session history by VIN and the built-in AI mechanic. You only pay for hardware, and a plain ELM327 or a $10 cable is enough to start.
Download Diagnost
Free program: scans every module on any make, live data, service functions and an AI mechanic built in. Finds the connected adapter on its own and picks the one that is on the car.
Other comparisons
Updated: 2026-09-05