Wheel speed mismatch (rear right wheel at GM)
Where to start
⚠️ This number is read differently too: in the GM numbering it is the REAR RIGHT wheel sensor, while several other makes use it for a mismatch between the four wheel speeds. If it is a mismatch, start with what costs nothing: tyre pressures and whether all four wheels are the same size. Different pressure and different wear give different rotational speeds, and the system reports that honestly. A spare of another size is the most common cause after a tyre shop visit. If it is a wheel code — the connector and the wire at the hub.
How to put together a report a mechanic will actually read
How the code is built
All codes in «Brakes, ABS and stability control»
How the app helps
CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.