 ...The E67 picked up even...  ...The E67 picked up even more terminals for total of 202, yet still featured only three connectors. |  The E38 module is similar...  The E38 module is similar to E67s, minus one connector.... |  ...Total terminal count was...  ...Total terminal count was slimmed down to a total of 153 pins between only two connectors. |
 When GM split the powertrain...  When GM split the powertrain control duties between sovereign units in 2005, the trans commands became the responsibility of a new transmission control module.... |  The new T42 TCM is a relatively...  The new T42 TCM is a relatively tiny thing, compared to older PCM modules. The units feature a single 49-terminal connector. Like the LAN-type ECM boxes, the TCM was designed to never be opened. |  Starting with the E40, some...  Starting with the E40, some of the newer LAN-type modules have casting numbers corresponding to their moniker. However, this casting number does not appear on 'all' modules, so consider your box lucky if it got marked. Shown in the red circle is an E67 casting number situated between the fins. |
 Control module terminals have...  Control module terminals have evolved much like the boxes they connect. The small LT1 connector shown horizontally at the bottom was actually fairly similar in style to the Gen III connectors shown on the left, but smaller. The three color Gen III connectors are shown, blue-green-red. The LAN-type controllers were introduced with a new-design featuring more tightly packaged connectors, as shown on the right. |  Smaller means better when...  Smaller means better when talking OEM controllers. The power and speed increased with each new (and usually smaller) controller. The ECM and TCM in the front are clearly smaller than older Gen III controllers shown in the background. |  GM's LAN-type controllers...  GM's LAN-type controllers all look fairly similar thus far, besides some subtle connector differences. None of these controllers interchange. |