Here are a few pictures of the AL5 board if anyone was interested.
http://tapatalk.imageshack.com/v2/14...de67a1485b.jpghttp://tapatalk.imageshack.com/v2/14...444c129169.jpg
Printable View
Here are a few pictures of the AL5 board if anyone was interested.
http://tapatalk.imageshack.com/v2/14...de67a1485b.jpghttp://tapatalk.imageshack.com/v2/14...444c129169.jpg
Ive always been surprised at how "simple" the Allison 5-speed TCM PCB was. Having personally taken apart both 5-speed and 6-speed TCM's, the difference in PCB design and construction is worlds apart. 6-speed TCM PCB is fully encapsulated, and has de-cased chips for the processor, communications chip, and memory. Its cool you can actually see the cores/internal proc architecture.
5-speed TCM has only 2 high-side drivers for trim a and trim b. All the rest of the solenoids are just fed from/tapped off of the ignition +12v input to the TCM and then controlled via low-side FETs. A lot of through-hole components, etc. Its really mid-1990's ECU design/technology.
And do you ever hear of them going faulty? Good design I think, not overly complex or shrunk too small. It is essentially a similar chipset of drivers, CPU etc as all the Delphi PCM's of this era.
That PCB sealer stuff is a PITA though!