We have been steering and accelerating by wire for a long time now.
Our brakes have also been under computer control for a long time now.
Auto transmissions as well.
With the advent of the BUS type networked electrical systems in cars a while ago, almost everything has been under computer control, from the power windows, to the radio, to the climate control, etc. It's almost all on a network and controlled by one of many computers and a network controller.
Even simple things like the reverse lamps and the brake lamps go through a network controller.
For instance, here is how the front fog lamps work on my 2008 Jeep:
FRONT FOG LAMPS
Vehicles equipped with optional front fog lamps include a front fog lamp relay installed in the Integrated Power Module (IPM), and a front fog lamp switch integral to the left (lighting) multi-function switch on the steering column. The front fog lamps have a path to ground at all times through their connection to the headlamp and dash wire harness. The headlamp and dash wire harness has takeouts with eyelet terminals that are secured by ground screws to the front end sheet metal within the engine compartment. The SCM monitors a hard wired multiplex input from the left multi-function switch to determine whether the fog lamps are selected, then sends electronic front fog lamp request messages to the FCM over the CAN data bus.
When the FCM receives a front fog lamp request message it then controls front fog lamp operation by energizing or de-energizing the front fog lamp relay control coil. The FCM also sends the appropriate electronic message to the EMIC to illuminate or extinguish the front fog lamp indicator. When the front fog lamp relay is energized, it provides battery voltage from a fused B(+) fuse in the IPM to the fog lamps through the fog lamp relay output circuit. In vehicles manufactured for domestic markets, the FCM will automatically de-energize the front fog lamp relay any time the headlamp high beams are selected.
The FCM also provides a battery saver (load shedding) feature for the front fog lamps, which will turn these lamps OFF if they are left ON for more than about eight minutes with the ignition switch in the LOCK position. The FCM will also turn OFF the front fog lamps if it detects that system voltage is less than 11.75 volts for more than about 30 seconds, and will return the front fog lamps to normal operation when it detects that system voltage is greater than 13.0 volts for more than about 30 seconds.
Each front fog lamp includes an integral adjustment screw to be used for static aiming of the fog lamp beams.