The following are excerpts from www.iwheeltravel.com:
These touristic buses stop at 23 different places covering main touristic attractions. They have ramps and wheelchair reserved spaces on board.
For an adult a 24 hours access costs 55MYR and a 48 hours access costs 95MYR. However disabled people pay children fees: 30MYR one way and 50MYR return. Tickets can be purchased in buses, online and sometimes in hotels.
www.iwheeltravel.com (listed under "KL Hop-on/Hop-off Buses").