Comma 4 Four released

[gerrylum]

Just swapped my Comma 3X for the new Comma 4 in my Rivian R1T. Unboxing, driving, and early impressions—plus a quick look at tuning Sunnypilot settings with Sunnylink Dashboard.

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[Fmc]

@gerrylum got a link to the magnetic release.

 

[gerrylum]

@gerrylum got a link to the magnetic release.

Not yet! Janka is working on a new version. He says hold off on buying any Comma 4 mount until it's done, especially for Rivian.

 

[Fmc]

@gerrylum I saw your video.. I was hoping I could use my old one

 

[gerrylum]

@gerrylum I saw your video.. I was hoping I could use my old one

Do you have a Janka mount currently?

 

[Fmc]

Do you have a Janka mount currently?

Chun adapter..

 

[gerrylum]

Chun adapter..

Ah nuts- Chia Chunli is the only supplier I haven't heard about working on a Comma 4 mount unfortunately. Only tinybear and Janka. I'll have to ask bgill66 if he's heard anything.

 

[Fmc]

Ah nuts- Chia Chunli is the only supplier I haven't heard about working on a Comma 4 mount unfortunately. Only tinybear and Janka. I'll have to ask bgill66 if he's heard anything.

Another good guy from La

 

[Singletracker]

Darn, I really want a Comma 4. Problem is, the long lead time showing on their website could conflict with my future schedule. For those who have already received their Comma 4, how long did it take? TIA.

 

[gerrylum]

Darn, I really want a Comma 4. Problem is, the long lead time showing on their website could conflict with my future schedule. For those who have already received their Comma 4, how long did it take? TIA.

They announced the Comma 4 at Comma Con on November 8th and started taking orders that day. By the time they started shipping a few weeks ago, they had a HUGE backlog.

That being said, they'll probably be able to get through the backlog by the end of January.

 

[Fmc]

Upsetting RIVN could not do a $1500 upgrade but glad comma figured this out

 

[vcao]

You can use either the Xnor (Lukas) or the Comma main harness for lateral control - you will have to add the Xnor longitudinal harness as well for long. If you use the comma harness, it is recommended to modify the harness for axm power to bypass and then add a fuse tap for power. Lukas already makes this adjustment on his harness and includes the tap. He also discounts when you buy both together from him and the overall isn't that much more and you don't have to make changes.

@gerrylum or @LivingInKaos - There was a note in the installation guide, "As of July 2025, Lukas’ harness does not use AXM power and includes a fuse tap. Skip this section if your harness from Lukas included a fuse tap."

I received my Xnor harness in August 2025. I've noticed suspension warnings that quickly go away and, worse, turtle mode. I have to hard rest the vehicle for turtle mode to go away. Is it possible that my harness still has the AXM power?

 

[gerrylum]

@gerrylum or @LivingInKaos - There was a note in the installation guide, "As of July 2025, Lukas’ harness does not use AXM power and includes a fuse tap. Skip this section if your harness from Lukas included a fuse tap."

I received my Xnor harness in August 2025. I've noticed suspension warnings that quickly go away and, worse, turtle mode. I have to hard rest the vehicle for turtle mode to go away. Is it possible that my harness still has the AXM power?

Are you using any kind of alternative power source like a fusetap in your setup? If not it is highly likely you are using axm power through your harness in which case yes you have a harness that still has the axm power connection.

However if you're using an alternative power source like a fuse tap it's possible you may still have the axm power connection which means you're using both at the same time which has the potential to cause electrical feedback between both systems.

Let us know what your setup looks like exactly and we can try to help you out.

 

[vcao]

Are you using any kind of alternative power source like a fusetap in your setup? If not it is highly likely you are using axm power through your harness in which case yes you have a harness that still has the axm power connection.

However if you're using an alternative power source like a fuse tap it's possible you may still have the axm power connection which means you're using both at the same time which has the potential to cause electrical feedback between both systems.

Let us know what your setup looks like exactly and we can try to help you out.

Sorry I left out some critical information. Yes I'm using the fuse tap. I think at the time it was an optional purchase. I'm connected in with Lukas harness and fusetap. The Comma is on the Beartech mount. At first I'd get suspension warnings, but the last update started getting me into turtle mode errors.

If thr Comma had AXM and fuse tap power, could that present a major issue? I assume I might have an older Lukas harness even though it shipped in August/September 2025. I'm going to try and get the harness back out, but it was a major pain getting it in the first place and I'm recovering from a dislocated shoulder.

 

[gerrylum]

I'm fairly certain you have an older harness. The easiest way to check is to disconnect the fuse tap and if the comma still powers on that means you do have an axm power connection on your harness.

Using axm power is bad enough since the axm seems to be very sensitive to power fluctuations but using axm power at the same time as a fuse tap can present serious problems as there is the potential for electrical backflow between the axm and whatever system you're tapping the fuse for.

If your harness does have axm power I would suggest removing the fuse tap for now until you can take the harness out and modify it to remove that power connection.

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