50% shorter wiring harness

[arnis]

So Elon mentioned, that Model 3 will have 1,5km of wires running all around. Model S has 3km.
Shall we discuss that?

If this video really has the full main harness, then this is extremely good result already (compared to BMW-s).

Most popular way to reduce harness length is to use modules everywhere.
For example, head and taillights - rather than having all kinds of sectors have separate wires, just using positive, negative and data wire is enough per one light assembly. Same with electric seats. Common positive, common negative and one data to actuate all memory/heating/motorized/SRS functions.

Other ideas:
One cooling fan for AC/glycol loops, no redundancy (except software limp mode if failed).
Tailgate specific module (camera, taillights, buttons, all have common power and one/two data channels..
HUD with minimal wiring directly from main computer.

 

[dsvick]

I don't know that a HUD vs the current dash display will be that different in amount of wiring. Manual doors and door handles will reduce wires. The 3 being smaller will reduce it somewhat as well.

 

[Cosmacelf]

That would be pretty cool if tiny low cost low power CPU or more likely gate array modules were embedded in mundane things like lights. Anyone have links to electronic design magazine articles about an architecture like this? Would Tesla do this on their own, or is the industry moving this direction?

 

[Bangor Bob]

Its an industry trend to make everything electrical a canbus module needing just a power connection and a tap off the appropriate canbus.

OTOH, it makes swapping out a failed electrical part (say, broken headlamp) more expensive since everything has a microcontroller in it and is usually integrated into a complete assembly, making it hard to replace just the failed sub-component (like a headlight housing, for instance).

 

[arnis]

Complex vehicles do have that a lot. My 2001 BMW has modules in driver and passenger door (driver door windows controls is actually a module) that incorporate lots of things, like mirror memory and folding. Signal for folding is sent to the other door module with one wire. Trailer module is in the trunk and some of the lights for trailers are actually not directly from taillights but rather a signal wire from main light module. One wire instead of many.

Climate control flap actuators all run on one special 3-wire parallel line. With time the number of actuators have grown from 4-5 to 20. Imagine having 60 wires just for actuators Actuators listen for command signal and then decide what to do on their own.
Steering wheel buttons send data either with analog (different button different resistance on same wire) or digital. Analog has been dropped as only one button works simultaneously.


That all was already used 20 years ago.

Has anobody seen Model S parking sensor wiring? Do they have all their own 3 wires that run to the main module (18 wires front, 18 wires rear) or all front are combined into one parallel line (similar to BMW heater actuators) and rear into another parallel line. This will require either new sensor introduction (coding) while changing or every sensor has it's own position it fits (different part number for each sensor location).
Expect 135-155 meters (440-510ft) of wire if every sensor has it's own connection to main module on Model S. Definitely place for improvement

 

[Reeler]

Modules are getting cheaper and cheaper as the chips, circuits, & protocols become standardized. The labor for switching out something far exceeds the couple dollar cost of the modules. It also makes self-diagnostics far easier as each module can test its own operation and report errors back to the main processor in the car. This configuration fits into Tesla's design philosophy of OTA updates if each module can also be upgraded OTA.