Started getting random system faults when using cruise control/driver assistance

[DD4ST]

All,
Within the last couple of months my 23 R1T DM has started throwing a system fault error periodically when using cruise control, with and without driver assistance. A message pops up saying the system is turned off and a system fault was detected. But I can immediately re-engage it. Happens in all kinds of weather, and when following or no one in front. Before I add this as a request to Rivian in the app, I was wondering if others had experienced this and whether Rivian had a fix.

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[Dave Cundiff]

I had intermittent "Take Control Now. System Fault Detected" issues for my first few months (Feb-April 2024), now have it again for Jul-Sep 2025. I can always re-engage immediately.

It doesn't seem to portend anything serious, but it's curious that service staff don't have any specific ideas about what causes it or what might fix it.

Best wishes!

 

[Kunzene]

All,
Within the last couple of months my 23 R1T DM has started throwing a system fault error periodically when using cruise control, with and without driver assistance. A message pops up saying the system is turned off and a system fault was detected. But I can immediately re-engage it. Happens in all kinds of weather, and when following or no one in front. Before I add this as a request to Rivian in the app, I was wondering if others had experienced this and whether Rivian had a fix.

I experienced this in my truck. They replaced a wiring harness, ASM module, and spoiler/antennas. I understand there can be other causes for a system fault and it took some time to pin down the cause in my case, but it solved the problem.

 

[pointless]

Hmm I’ve seen this a lot. Not sure if I’ve seen this since my TCM and antenna were replaced for SOS Failure issue.

 

[RivAW]

Have you bothered trying a full reset? Your truck is more of a big computer on wheels and software gets bogged down occasionally. Some owners even commit to a reset every (so often) to clear caches etc…

 

[CO-Ed]

I get the "Adaptive Cruise Control: System Fault Detected " message often on my 2022 R1T. Resets don't make it stop. I've captured diagnostics lots of times but Rivian Service says there's nothing in the logs. It's not reproducible on demand. I've had this issue since May2025. Before that I was getting an alert and blip of message that I could never read because it disappeared too fast. Recently I've even gotten a message that ACC is not available at the same time it shows that Highway Assist is available.

 

[ceetiger]

I had my R1S in for service a couple weeks ago, to adjust the liftgate. I live in the south, and when out in the sunshine, the liftgate would "rub" against the car roof. Anyway, I also had them look into this cruise control "failure." According to my service shop in Duncan, SC, this seems to be a firmware issue, and is to be corrected with an upcoming update.
And, since the 2025.26.01 update, it had not recurred on my R1S.

 

[CO-Ed]

I've had multiple occurrences of Highway Assist/ACC issues including the system fault detected message since installing 2025.26.1 and after a reset following 26.1 install. If there's a fix in an OTA update, I didn't get it in 26.1.

 

[Martyr]

All,
Within the last couple of months my 23 R1T DM has started throwing a system fault error periodically when using cruise control, with and without driver assistance. A message pops up saying the system is turned off and a system fault was detected. But I can immediately re-engage it. Happens in all kinds of weather, and when following or no one in front. Before I add this as a request to Rivian in the app, I was wondering if others had experienced this and whether Rivian had a fix.

 

[Martyr]

This happens on my 2023 R1T quite frequently and, as others note, I can reengage cruise control immediately after. I reported issue to service and they replaced a module but the issue returned. I brought in in again and they could find no faults. The issue persists even with latest software update.

 

[Mathme]

I've experienced that same issue numerous times and had it into the SC to look at. They couldn't find anything in the logs. so now I've been capturing the logs when it happens and noting the date and time. I have another long trip planned in a couple of weeks and if it's still happening after that time, I'll open another ticket with my logs.

Note: I just learned this the other day but you can capture the logs while driving by: 1) locate your driver profile name in the upper left corner of the center display; and 2) press and hold on your name for about 3-5 seconds. Service also says it helps them if you have a note of the day and time as well.

 

[gvtucker]

I have gotten the same thing, System Fault Detected, several times. Since the last software update I haven't seen it.

I have an SC appointment this week for a separate issue, and I'll bring it up to them and see what they say.

 

[eRacer]

I wonder if this has anything to do with abandoning the mobile eye camera? I too have been getting these random errors more frequently now after the most recent update.

 

[DD4ST]

Thanks for all the help. I did not know that about capturing a log, but will try that (while driving!). I’ve tried the soft reset, but willl try the hard reset too. But honestly this sounds like a prevalent issue. I’m guessing a poor electrical connection somewhere.

 

[schlosrat]

I was getting the intermittent error where you could immediately re-engage ACC, but then the other day, I got a persistent one where I could not immediately re-engage. In fact, any attempt to re-engage ACC on that drive would trigger the error. This was after installing the Comma AI with the Lukas harness for getting power from a fuse tap. It's possible the two are related, but also possible they are not, as I got the intermittent issue before installing the Comma, and I suspect many others on this thread are getting this issue without a Comma device installed.

In my case, I solved the persistent error by parking and doing a hard reset. I later heard from someone on Discord that merely parking and then starting a new drive might have fixed it. It hasn't happened to me again since then, but I'll try that as a less severe solution if it does - not that performing a hard reset is in any way difficult, just moderately less convenient, as it takes a bit longer.

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