The Engine Control Module, or ECM, directly controls the engine. Still, it can’t do that properly without the Transmission Control Module or TCM and PCM, which work together and exchange information.

And, should it tickle your fancy, BulletProof Diesel also offers a billet water pump and upgraded fuel injection control module (FICM) for the 6.0L Power Stroke.

During their final years, a handful of automakers experimented with computer control of the humble carb, trying to squeeze out every last bit of efficiency and reduce pollution as much as possible.