Got all the brakes light on dash. Mechanic said the speed sensor in one rear need to be replace, but that means the whole wheel bearing has to be replace. Is that common practice and true?

He said that usually just get a speed sensor would even cost more than the whole wheel bearing because it has to be direct by the manufacturer or something along that line.

Also, if the speed sensor is the culprit, is that mean the km/h on my dash is not correct? I don't know if the ABS sensor and speed sensor is the same thing, or maybe it is not the same but within the same part as a one sensor for both? Anyway, the car brake pressure is fine he said so I could drive until the parts arrived. I would just have no ABS until then.

Thanks!