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

[Dave Cundiff]

On a recent 3 hour drive, I had the ACC abruptly cancel, "Adaptive Cruise Control Cancelled: System Fault Detected" shows on the dash, happened randomly and four total times on the entire round trip. All stock Dual Motor R1t, no Comma Installed.

That's once again become frequent, maybe every 30-50 miles, on our R1S (though not so much on the R1T). It's annoying, but doesn't impair function significantly as far as I can tell.

Looking forward to solutions!

Sponsored

 

[gvtucker]

So I had a service center appointment for this but also for another unrelated item. And while the people at the service center in Knightdale were great and they did a fine job with my R1T, they were unable to duplicate this specific problem and thus they couldn't fix it.

It happened modestly often for a while, every time I took a longer trip (>100 miles) it would happen at least once. And then all of a sudden, it has stopped. Only happened once in the past two months.

The service person told me that the next time it happens, long press on your name on the screen, then do two quick presses on the hazard button. That lets the programmers know the specific place on the software code when it happens.

 

[RivAW]

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 didn't bother reading all fate other replies.....but did you try a full reset? That's usually the first/best option before needing to submit a service ticket. Your truck is more of a computer than a vehicle and software sometimes gets bogged down.

 

[CO-Ed]

didn't bother reading all fate other replies.....but did you try a full reset? That's usually the first/best option before needing to submit a service ticket. Your truck is more of a computer than a vehicle and software sometimes gets bogged down.

Full resets have not prevented these issues from happening for me over the past 5 months. I have it (ACC: System Fault Detected) happen almost weekly. Also the service center has not found anything in the logs I captured knowing the exact minute it happened.

For those of us that this happens to, it's an error the vehicles throw but the software is not writing anything to the logs. I've been told there's a fix in 2025.34. We'll see.

I'm in a 2022 R1T QM VIN 13xxx with 48k miles and have never installed Comma or anything like it. I first noticed and reported the problem in May2025.

 

[Mathme]

This is a known issue that popped up about 4-5 months ago and happens to lots of us. I had it happen 5-6 times in a 400 mile trip this past weekend. The SC looked at it and couldn't find any issue. They asked me to capture the logs and resubmit a ticket but at this point it is almost more bother than it's worth. Based on what's seen just here, this is a widespread issue and enough of us complained so it should get fixed. If it's not fixed in the next 1-2 updates, then back in it goes.

 

[Dave Cundiff]

This didn't just "pop up" in spring 2025, @Mathme. Mine first occurred while leaving Portland SC with our R1S on 2024-02-16, with around 20-30 miles on the odometer.

I'm still extremely pleased with our Rivians. Compared to the advantages, getting popped out of ACC is small. I'm waiting patiently for Rivian to figure this out and fix it, then I'll push to have our R1S included in the fix.

Thanks to all!

 

[CO-Ed]

Anyone else have this issue (ACC/Highway Assist cancelled for no reason) since installing 2025.34 installed?

I was told that there would be a fix for this issue in 2025.34, but, after installing 2025.34, doing a full reset a day later, I just had it occur yesterday.

When it happened, I captured logs and asked Rivian Service if they can look at the logs before I take the truck in (every time I've taken it in for this in the past they tell me there's nothing in the logs I captured when it's happened so therefore there's nothing they can do address it).

 

[ciderarchitect]

I am on the latest software, and still having the issue.

 

[Count Orlok]

Anyone else have this issue (ACC/Highway Assist cancelled for no reason) since installing 2025.34 installed?

yes

 

[LLJJ]

Anyone download 2025.38 and notice if it fixed the issue? I didn’t see anything in the release notes about it, but my update won’t download so I can’t test.

 

[ciderarchitect]

I just wanted to chime in that it seems this issue is fixed for me. I think the Halloween software update (2025.38.0) must have had some magic, as on a trip to Tacoma a month ago I was still fighting the System Default, but on a quick trip to Seattle earlier this week, ACC and Driver+ worked flawlessly. So glad I postponed the service appointment I'd scheduled to look into this.

 

[CO-Ed]

Same here - haven't had the issue since installing. 38

 

[waitingforrivian]

I just wanted to chime in that it seems this issue is fixed for me. I think the Halloween software update (2025.38.0) must have had some magic, as on a trip to Tacoma a month ago I was still fighting the System Default, but on a quick trip to Seattle earlier this week, ACC and Driver+ worked flawlessly. So glad I postponed the service appointment I'd scheduled to look into this.

Counter example after installing 2025.38.0, I got my first system fault while using ACC. (Never happened to me before)

 

[LLJJ]

Counter example after installing 2025.38.0, I got my first system fault while using ACC. (Never happened to me before)

Mines in service now and they are replacing the AXM module. Hope that fixes it!

Counter example after installing 2025.38.0, I got my first system fault while using ACC. (Never happened to me before)

 

[GodSpeedRebel]

Picked up my R1T from the service center today and asked a lead tech about the dumb-cruise shutting down. He said they are aware of a bug that crosses Driver+ and dumb-cruise that seems to be causIng it. He expects a future software update to address.

Have they resolved your issue yet? I’ve had issues with mine since December 8th and was told last week there is no permanent fix yet. My dash went dark and they replaced the axm module. The screen worked after that but all the Driver+ features only work intermittently.

Sponsored