A Rivian R2 that had been in its owner’s hands for a single day was towed to a service centre after failing to wake from deep sleep, and the company’s technicians have ordered a control module rather than a replacement battery.
The owner, posting to the r/RivianR2 forum on Reddit on Wednesday evening under the handle ‘Evening_Income8571’, wrote that the SUV “slept and never woke up” after displaying a 12-volt battery message.
Alongside the post, the user shared two screenshots of text messages from Rivian service alongside a photograph of the vehicle on a flatbed.
The second of those messages is timestamped 2:18pm US Eastern time on Wednesday, placing the post after it.
The thread had drawn more than 60 comments by Thursday morning US Eastern time.
What Rivian Told the Owner
The first message came after technicians left the vehicle overnight to reproduce the fault.
Service wrote that they “were able to duplicate the concern” after letting the vehicle sit overnight and enter deep sleep, and that a diagnosis was still being worked on.
The early indication, the message said, was that “the low voltage system is not operating correctly” once the vehicle enters that state.
A second message, timestamped 2:18pm on Wednesday, closed the diagnostic loop with a part order.
Technicians had determined that “the rear multifunction module will need replaced,” the message said, with the part ordered and on its way.
Neither message mentions replacing the 12-volt battery.
Why the Distinction Matters
Rivian has accumulated several separate problems that all present to a driver as a 12-volt warning followed by a vehicle that will not open or move, and conflating them produces a misleading picture.
The best known is premature failure of the lead-acid 12-volt battery itself on first-generation R1T and R1S vehicles.
The company has managed the problem through proactive replacement campaigns since late 2024 and which EV covered in June, when an owner reported taking his third battery in two years and three months at 13,000 miles.
Owner telemetry posted to the Rivian Forums attributes that pattern to duty cycle rather than defective cells, describing an 18 amp-hour battery that deep-cycles to around 12.0 volts before the charging algorithm intervenes, roughly three times a day.
A second and distinct problem is hardware.
Under customer satisfaction campaign RCA-78-25-004, Rivian is replacing the 12-volt battery and both the upper and lower brackets on some model year 2025 R1T and R1S vehicles built with brackets that could damage the battery.
The bulletin’s own description of the symptom is a 12-volt battery warning on the instrument cluster, or an inability to power up or drive the vehicle.
A third is software.
An update in March 2023, version 2023.6.2, broke the charging path between the high-voltage pack and the low-voltage battery, killing batteries and stranding owners. Rivian’s remedy shipped in 2023.10.00 with a release note describing an internal loss of communication that drained the 12-volt batteries.
A fourth category, and the one this case falls into, is control modules.
Rivian ran a service campaign on early 2022 R1T vehicles whose body control modules had been incorrectly assembled by a supplier and could fail suddenly, leaving the truck in a limited performance mode and without exterior lighting or electronic door locks.
Under campaign RCA-86-25-001-1, dated March 5, 2025, the company replaced secondary driver assistance modules on 2022 R1T vehicles built with early revisions the bulletin describes as susceptible to early failure.
None of these has ever been the subject of a safety recall. Every one has been handled as a customer satisfaction campaign or a warranty repair.
A module that fails to enter or exit a low-power state can hold systems awake, draw current while the vehicle is parked and leave the low-voltage side unable to boot the controllers that close the high-voltage contactors.
The driver sees a 12-volt warning and a dead car despite the fact that the battery may be entirely healthy.
The Part in Question
Rivian’s R2 consolidates five components that were separate on the R1 into a single assembly the company calls the Powerhouse.
Vidya Rajagopalan, Rivian’s Senior VP of Electronic Hardware, told The Drive in June that the assembly combines the onboard charger, the DC-to-DC converter, the DC-to-AC converter, the cell zone controller and the battery management system.
The Autopian, shown the hardware during the same round of technical briefings, listed the south zonal — the controller for components at the rear of the vehicle — among the five.
Accounts of the exact five differ in how the zone controller is named, and Rivian has published no component list of its own.
The assembly mounts to the cast aluminium rear floor structure and is serviceable from under the rear seats without dropping the pack, in contrast to the potted and non-serviceable cell volume around it.
Rivian described the failed part only as the rear multifunction module, and has not said which element of the assembly is being replaced or what caused the fault.
Deep Sleep
The failure occurred in the operating state Rivian singled out three months ago as one the R2 had improved.
Wassym Bensaid, Rivian’s Chief Software Officer, wrote during a Reddit question-and-answer session on May 21 that the R2’s high- and low-voltage architecture had been improved to reduce dependency on the 12-volt battery by “reducing sleep power draw and increasing the capacity of the mini-DCDC converter.”
Minor power draw during sleep would be carried by the high-voltage battery, he wrote, minimising cycling of the 12-volt battery and prolonging its life.
That mini-DC-DC converter sits inside the same consolidated assembly as the rear zone controller and the battery management system.
Consolidation is central to the R2’s cost case, cutting a further 2.3 miles of wiring, 44 pounds and 60% of connectors relative to the second-generation R1, which had already reduced the vehicle from 17 electronic control units to seven.
A single module failure in that architecture can therefore affect sleep-state management, low-voltage conversion and battery monitoring at once.
A Separate Module Problem in July
Rivian flagged a module fault on early R2 vehicles roughly a month before this failure, though the two have not been shown to be connected.
An owner awaiting a vehicle with a VIN in the 2100 range wrote on the Rivian Forums in mid-July that two delivery appointments had been cancelled, and that a Rivian representative told him a number of R2 VINs had been flagged for a faulty communications module on the high-voltage battery requiring the pack to be dropped.
The two descriptions do not match. That module is described as sitting on the high-voltage battery and requiring a pack drop; the part ordered this week is described as a rear multifunction module, and the Powerhouse is serviceable from under the rear seat.
Whether service advisers used different language for related hardware, or whether these are genuinely different parts, cannot be established from the available evidence.
The timing is the more consequential difference. The July action held vehicles before delivery. This vehicle failed after delivery.
The Quality Context
The failure lands in a rollout EV has been tracking since customer deliveries began in June.
EV reported in July that the R2 had produced five separate quality reports in the 47 days since deliveries started, spanning paint, exterior lighting software, the high-voltage battery, charging hardware and cabin components.
Additionally, EV exclusively revealed that the breakdown in pre-delivery inspection quality followed the October 2025 restructuring that cut more than 600 jobs and dismantled the vehicle operations organisation built to catch such faults, according to a person familiar with the matter.
Deliveries have also been disrupted by rail scheduling problems that pushed handovers into August, and VIN assignment slowed to roughly 500 a week through late July from a peak above 1,300 in a single week, before accelerating again in August.
Rivian delivered 12,194 vehicles in the second quarter and raised full-year guidance to between 65,000 and 70,000 units, of which 20,000 to 25,000 are meant to be R2s.
The company does not break out R2 deliveries.
