Short answer: the OBDLink MX+ is the pick for a GM, because OBDLink publishes support for GM SW-CAN by name — the single-wire CAN network that carries a large share of GM body, ABS, TPMS and transmission data — and lists the enhanced parameters it reaches. Most scanner listings claim "GM coverage" without naming a protocol, and on these vehicles the protocol is the entire question. If you want a screen of your own and bi-directional control instead of an adapter, the Innova 5610 is the alternative.
What we judged these on
1. Whether the maker names the protocol
This is the criterion that sorted the field. "Works on GM" is true of every OBD2 tool ever made, for engine codes. OBDLink states GM SW-CAN support explicitly and lists which enhanced parameters follow from it. We weighted a named protocol far above a named brand, because the brand claim costs a manufacturer nothing to print.
2. Which modules it reaches on paper
ABS, SRS, TPMS and transmission are the four that GM owners come looking for, and all four live beyond the legislated protocols. Each pick above publishes its own list, and we have used those lists rather than inferring from a model number. Best for ABS and SRS codes covers that question across all makes.
3. Transmission fluid temperature
A specific and unusually practical one. Several GM transmission fluid procedures are specified at a fluid temperature, which means the job is not doable without a tool that reads it. Innova publishes transmission temperature in its live-data list; OBDLink publishes transmission temperature among its enhanced parameters. Most sub-$100 tools do not have it.
4. Electric parking brake retraction
On late-model GM vehicles with an electric parking brake, the rear calipers cannot be compressed until the motors are retracted by a scan tool. Autel lists EPB among the MK808S service functions. Without it, a rear brake job stops at the caliper.
The four picks on what they publish
| Pick | Format | What the maker states for GM-relevant data | Bi-directional |
|---|---|---|---|
| OBDLink MX+ | Bluetooth adapter | GM SW-CAN named; ABS, SRS, TPMS, A/C, transmission temp, wheel speeds | App-dependent |
| Innova 5610 | Corded handheld | Engine, transmission, ABS, SRS; transmission temp and TPMS live data | Yes |
| Autel MK808S | 7 in Android tablet | All available systems; 28+ service functions incl. EPB, SAS, DPF | Yes — active tests |
| TOPDON TopScan Pro | Bluetooth dongle | Full-system code reading, 13 maintenance services | Yes — bi-directional control |
Note what the table does not say. None of these makers publishes a model-by-model GM compatibility matrix, and enhanced coverage is make and model-year dependent on every tool in this category. Check your specific vehicle against the maker's own coverage lookup before buying — that is true at every price.
Which GM vehicles this applies to
All of them, in the sense that the protocol question is a GM-architecture question rather than a model one: Chevrolet, GMC, Buick and Cadillac share the networks. The practical cases we see most often are a Silverado or Sierra with an ABS or traction light, an Equinox or Terrain with a TPMS fault that a generic tool reports as nothing, and any late-model GM needing a transmission service at temperature.
If your fault is a plain check-engine light, none of this matters and a cheap handheld is enough — best OBD2 scanners under $100 is the right page. The protocol only becomes the problem when the light is not an engine light.
Before you blame the scanner
Two things catch GM owners out often enough to be worth stating, and neither is a scanner fault.
The first is the port itself. The OBD2 connector is required to be within reach of the driver's seat, but on GM trucks and SUVs it is frequently tucked high under the dash edge above the pedals, sometimes behind a hinged cover, and it is easy to conclude a tool will not connect when it has simply not seated fully. Push until it clicks, and check the connector pins are clean — a port that has had a dongle living in it for years can be worn.
The second is ignition state. Most scanners need the ignition in the key-on-engine-off position to communicate: the modules powered up, the engine not running. On a push-button start vehicle that means pressing the button without your foot on the brake, which is not obvious if you have never done it. A tool that reports "no communication" on a car with the ignition fully off is behaving correctly. Why won't my OBD2 scanner connect works through the rest of the list.
Why this page has a Ford twin
Ford has the same architecture problem with a different name: MS-CAN rather than SW-CAN. OBDLink publishes support for both, which is why the MX+ appears as the pick on both pages — it is the same single capability solving the same single problem on two manufacturers. Best OBD2 scanner for a Ford is that page, and the reasoning transfers directly.
What we would buy for a GM
The OBDLink MX+, if you are happy using your phone as the screen — it is the one tool here whose maker names the GM network by name rather than the brand, and the enhanced parameter list that follows is specific enough to check against your own problem. If you want a self-contained tool with bi-directional control and no subscription, the Innova 5610. If you are facing a rear brake job on a vehicle with an electric parking brake, the Autel MK808S, because EPB retraction is the function that makes the job possible at all.