05 Volvo xc90 ABS pump runs constantly

My buddy has a 2005 Volvo XC90 2.5t. He recently sent his ABS module to someone online that claimed to be an expert at rebuilding them. The initial reason for needed the rebuild was do to an ABS light with fault codes and erratic transmission shifting. Volvo quoted $1,200 to replace it and that is too much. After receiving the unit back from this guy online the ABS light stayed out but after re-installing the unit back into the car the erratic shifting returned that had gone away when the module was out of the vehicle. A few months later the ABS light came back on again. The online guy had my friend ship it back to him for a “complete” rebuild and reprogram. Now after installing the ABS module back in the ABS pump runs constantly even with the key out of the ignition and the ABS light is back on. We pulled the fuse to the ABS pump to prevent from burning up the pump. Volvo makes there codes a big secret so my scan tool won’t pull them, Any suggestions? Current millage is 113k.