It was 101/02 MAS - SBC Passenger. Later, got curtailed as 101/02 AJJ - SBC Passenger in 2008. Later got renumbered to 56261/62 AJJ - SBC Passenger. Later, got curtailed further between AJJ and JTJ. As of now, 06551/52 SBC - JTJ MEMU has more or less the same schedule between SBC - JTJ - SBC. So, 06551/52 seems to be the successor of 101/02( 56261/62) MAS/AJJ - SBC Passenger.
P.S. - I used to travel a lot by 101 MAS - SBC Passenger between WFD and SBC between 2006 - 08.