Ever wondered what the inside of the 2006-2007 Cummins CM849B ECM looks like?
To get the ECM opened up like the picture below pretty much renders the ECM useless because of the way the case is wrapped around a frame (not shown), the case ends up looks like it's been run over by a bus (so don't try this on your own ECM).

The main sections of the ECM are shown in the picture below.
1 - This is the Injector drive circuit with the big green charge capacitors clearly visible.
2 - The C1 & C2 connectors underside.
3 - The 'brain' section of the ECM with the CPU, Flash memory and RAM.

The CPU is from the popular Freescale PowerPC range, this CPU is used in many ECM's from GM, FORD and Chrysler, to many European cars. The PowerPC CPU core was also once used in Mac's and numerous gaming consoles (Xbox360, PS3, Wii).
Cummins first started using the PowerPC processor as far back as the 2003 model ECM's (CM846), which was years ahead of most other manufacturers (Delphi, Visteon, Bosch) switching to these CPU's for their controllers.
Notice there is no solid PCB as such, everything is mounted on a flexible type PCB, making component level repairs almost impossible.