2012 Allison 2500PTS, School Bus, Transmission ECMs, Fits to: Freightliner B2, (Used) 2011 Allison (AT), TRANSMISSION ECM- ECM Model: A51, Serial Number: BK5536N1107102AF, Part Number: 29545536, Trans Model: 2500PTS, Serial Number: 9730032476, Part number: 29550042, Voltage: 12V, Pin Plug: 80 pins, Rectangular Plug, For more information about this item, give us a call. We ship Worldwide! (CRG HEAVY TRUCK PARTS) 929 W PULASKI HWY, ELKTON, MD 21921, Serial# BK5536N1107102AF, Truck Year 2012, VIN 4UZABRDT5CCBF9312 4UZABRDT5CCBF9312