The ABS light has is not about "brake function" so of course the brakes should pass a test. ABS is about deciding when and how to apply the brakes, whether to "pump" the pedal or not to avoid skids. The light indicates a problem with either the wheel speed sensors or the ABS computer ability to manage the brake pressure. An intermittent ABS light is almost always a wiring problem (loose or corroded connection) or a faulty wheel speed sensor. The brakes still brake fine, but the ABS controller cannot avoid a skid if the driver jams too hard on the brakes.
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC