Spring brake chambers release the shoes with air pressure, so the first thing to check is whether the circuit has built full pressure. Second is the parking brake switch and its circuit itself — the control unit thinks the parking brake is still set and will not let the truck move.
Part of the brake circuit or ABS/EBS is out of service. The pedal may still feel normal — until the first emergency stop or descent.
Next comes longer stopping distance, a skid on a slick surface, failure on a long downgrade. This is the case where "I will take it slow" does not work.
Let the air system build to working pressure and listen for leaks. Don’t drive with faulty brakes.
The answer depends on the code, not the light. A yellow light is a warning; a red one means do not move. But even under a yellow light there are faults that require stopping right away — low oil pressure, overheating, lost brake pressure. Enter the code — the reference will tell you plainly whether to keep driving or stop.
Know the code number? Type it into the search — or paste the whole list from the scanner and we will show which fault is the real one.