Seeing as how it has new rear wheel cylinders & some new brake line installed, why not consider running this puppy by a trusted brake shop & let them have a go at bleeding the system with their scantool & a vacuum source connected to the wheel cylinders.

They'll soon know if the RABS module is faulty.

If you replace the ABS valve, you'll still need a shop to hook up their scantool to actuate & bleed the air out & sometimes this is tricky.