Has anyone else ever gotten this "Shift System Malfunction" error on the cluster after starting their car? It's happened to me twice now, on these coldest of mornings. It's the least severe of the possible shifter error messages according to the manual, it doesn't say anything about putting the car on level ground or applying the parking brake. It goes away once you restart the car. It seems to be related to the cold weather, is it indicating the gearbox is too cold to shift before the car has a chance to warm it up? A trip to the dealer service this week isn't too practical with the holidays and all. Going to warm up the next couple days in NY, let's see if ir re-occurs.

Have you gotten software update? Update related VVT locking pin? This may be reason, as VVT locks for the first few seconds to warm the car, but due to issue it may stay engaged. Not sure if it would cause shift error as it says MIL (Check engine)

No check engine light. Supposed to be over 30 degrees tomorrow morning, I am betting I don't see it.

I have gotten that message several times over the past 16 months or so since I bought my RX. It has only happened when it was around 10* F or colder. When I asked the local dealership service advisor about the message, he just brushed it off and said it was due to the cold temperatures; didn't seemed concerned about it whatsoever. Every time that this message appeared the car drove fine and the message eventually went away.

I have recently gotten the VVT locking pin software update and have not seen the "Shift System Malfunction" message since then, but the outside air temperatures have been very mild so I really don't know if the update solved this issue or not.

The bottom line is I don't think that you have anything to worry about, but of course these messages are definitely a little concerning at best.

Mild in Alaska? Anyway, thanks for the tip, I will get to the dealer after the holidays.

Yep, staying around 28-34* F for days (weeks?) lately. Not uncommon.

I am curious to know what your dealer says about the issue and would appreciate a follow-up report if you don't mind!

My question is, do you have your parking brake to set whenever you put it in park? Or not? When I bought ours, the dealer had it set to whenever you pushed the park button, the parking brake automatically activated. I turned it off since we always park in a level garage & don't really need it. But wondered if I parked on a hill without it, would it put the parking pawl in transmission in a binding & cause that exact issue.

VVT locks because there is no oil pressure to the cam phaser which would allow it to slap around back and forth internally. It’s locked until oil pressure is adequate.

I've seen it once or twice during cold morning starts. Every time turning the car off and back on again makes the message go away.
I have done the "VVT locking pin software update" but I still see it.

A VVT locking pin error would give a check engine light due to valves opening/closing not at the expected times in the combustion cycle. It would not give a shift system malfunction error.

I had this fault yesterday on my wife's 2023 RX (Gas). It was very mild for December here in Michigan, about 55F, so I don't think it was caused by cold temperatures. The car had been sitting undriven in the garage for a week over the holidays before we took it out to go to the movies (Off topic, but the Bob Dylan movie, "A Complete Unknown," was very good). The shift system malfunction fault alert came as soon as I backed out of the garage and it didn't clear in the 6 miles to the movie theater. On the way there I noticed that the auto-stop/start never engaged at stoplights. After the movie the fault did not reappear upon startup and driving home. So, I'm wondering if maybe one of the causes of the car throwing this fault is a low battery since the car had sat undriven for a week.

In my situation I don't believe that a low battery voltage causes this message to appear as the car is driven almost daily, but I suppose that it is a possibility. Low temperature (in my case) or sitting for a week (your case) = lower performance of a FLA battery = shift system malfunction notification?

Again, I suppose that it is possible, since we don't know what is causing this message to appear, but I really don't think that battery condition is causing this message.

Curious to know what your local dealer has to say about this should you choose to pursue this with them.

Funny you mention the low battery condition - I wasn't using the car during the period of very cold temps here in the NE, and later when it warmed up - the shift error was gone, but the car was asking me for a PIN number (which I didn't know) so I had to go through a PIN reset procedure through the head unit and the app. I assume this PIN reset was due to the battery being undercharged during the idle period of cold weather - however the car did start right up.

I think that at this point, since we have no idea what is causing this message to appear, we all keep an open mind as to what could be causing it. This being said, I agree with @Urlik that the VVT software update or lack thereof has nothing to do with the message. See post #10.

From what I have learned over the years, I believe that low voltage in the electrical systems of modern vehicles can wreak all sorts of havoc. The more that I have thought about this, the more plausible it seems that this may be the cause. @lexusnyca , your PIN reset validates this IMHO; your battery got discharged to the point that it still started the vehicle, but other things/systems were affected.

Perhaps an interesting experiment would be to hook up a battery trickle charger when cold temperatures and/or prolonged storage is expected and see if this keeps the message away. I will try this approach when I have an opportunity and report back.

Back with an update.

The past two mornings have been fairly cold, between 0 and 5* F. I drove the car on both of these days and I fully expected to see the shift system malfunction notification as I had in the past at these temperatures. The notification never appeared.

I'm really not sure what to think at this point.