Rivian and TE Connectivity on where zonal complexity hides

Ask an engineer where a vehicle's complexity lives and the answer used to be the engine bay. Ask a harness engineer today and the answer is more awkward. The complexity does not vanish when an OEM goes zonal - it moves, and someone has to decide where it lands…

That question ran through our livestream on the electrical backbone of the software-defined vehicle, where Dmitry Fudym, Principal EDS Engineer and Manager at Rivian, and Bernard Vetten, Senior Principal Field Application Engineer at TE Connectivity, were pressed on how theory survives contact with a moving assembly line.

Five short clips below capture the sharpest exchanges, and each rewards the two minutes it takes to watch:

Fewer inlines, less time on the line

Rivian's headline numbers are well known by now, with ECU count falling from 17 to seven on the R2 and a powerhouse module absorbing several functions besides. Fudym was keen to point past them. The goal his team set was simpler and harder, which was to cut the inline connectors sitting between main harness families.

The strategy is refreshingly practical for wire harness. "No inlines means fewer circuits. It means less time required to install those harnesses during our general assembly," Fudym said. The principle came with a standard of proof. "We created that goal because we said every line, every inline connector needs to earn its place, needs to provide value."

Rivian had the evidence to hand. "We knew that we could do better than the R1 designs that we had from the R1 experience because we had so many inlines." Delivering on that meant packaging the zone controllers strategically and connecting as many harness families as possible to each one, which Fudym called "absolutely crucial."

Where did the complexity go?

Vetten had already conceded that zonal architecture is no free lunch, and Fudym took up the point directly. Taking a cut lead, a wire with two terminals, and asking how best to move a signal from A to B leads somewhere unexpected. The best answer is often to put that burden on an existing circuit board.

"The complexity - if you want to call it that - we shifted effectively into the zonal controllers," he said. He was candid about the limits. "Again, if you do not plan early enough, you cannot come in halfway through a development cycle and say, 'I want to stick 10 more circuits in this controller.' You might be too late."

There is a second dividend that rarely makes the slide deck. Many OEMs carry a long tail of part numbers for each harness family. "In our case, we have literally one or two part numbers, and that is intentional," Fudym said. "We do not need that level of complexity in the harness or in the vehicle in general."

And the organisational point is just as pointed. Harness and systems engineers, he said, must be "getting a seat at the table during those early architecture discussions." Rivian's vertical integration made that easier. Suppliers and OEMs without it will need to work harder for the same access.

Why 800V is no simple upgrade

Vetten's clip lifts the bonnet on a change that many assume is mostly about thicker insulation. Asked what actually changes in connector design between 400V and 800V systems, he was direct. "It is definitely a combination, but mainly it is the creepage and clearance requirements."

Battery electric vehicles began in the 400V range, he explained, with a few outliers already higher, and the industry is now shifting to what he called "800-volt plus", anywhere between 800V and 1,000V. The rulebook is consistent. "The main specification everybody is following is IEC 60664, which is dictating some of these creepage and clearance requirements."

Then of course, comes the material. The comparative tracking index, or CTI, of the plastic dictates the distances required, and a connector maker's instinct is to choose the best possible material to keep the housing small. Vetten did not oversell that. "With everything in engineering, everything has pros and cons." The trade-off is worth dwelling on, because it is where the marketing story of higher voltage meets the packaging reality. Less copper is the prize. If clearances swell the plastic and the connector footprint, part of that prize is handed back.

Small housings, unforgiving signals

Data, according to our guests, is now a first-class citizen in the harness. "We start to see quite a lot of vehicles with standard already having up to, like, five-plus cameras in the vehicles," Vetten said. Each camera brings a data lead, and a data lead is a different animal from a power connection.

The criticality shifts towards "the crimping process, some of the process tolerances, but also the tolerances within the connector housing." That extends to headers and even the shroud designs on zonal controllers. Vetten's example is memorable for its simplicity. "For example, in a data connectivity assembly, the air gap between the mating halves would just degrade the signal."

The engineering is only half the job. Signal integrity specialists at OEMs and Tier 1s already know this, but Vetten argued the message must travel "all the way down to the EDS team and all the way down on the assembly line that some of these components are a bit more critical." It is a communication problem as much as a design one, and it is the kind that surfaces late and expensively.

Could AI retire the spreadsheet?

The final clip is the most forward-looking. Fudym used temperature validation as his test case, and started with a note on how Rivian's requirements differ from many rivals. "If a cable is rated for 125, we are usually good. Our operating temperature is usually at 85°C, because we do not have to worry about exhaust, internal combustion engine."

From there the leap is short. Picture a tool smart enough to know where every cable runs and to check each circuit for a temperature problem automatically. "That is not something we need an Excel spreadsheet for anymore," Fudym said. Such a tool could deliver a report, and when a new circuit arrives, the same check runs again to show what changed.

It is a modest ambition described with some restraint, and perhaps, that is what makes it even more credible. A well-scoped assistant that removes a repetitive check does more for a design release engineer than a grand promise of autonomy.

Watch the whole conversation

These five exchanges share a theme, which is that the industrialisation of the electrical backbone is decided in early, unglamorous choices. Which inline earns its place, which controller absorbs which circuit, which material sets which clearance.

The full livestream goes further, into the Rivian powerhouse module, the future of automation and the questions posed by the audience. It is available on demand, and it is worth an hour of any harness engineer's calendar.