I travel frequently and almost any time I leave my car sitting in the garage for a week or more, I receive upon startup a "shift malfunction" error message directing me to check the owner's manual. The message persists until I shut the car off. It does not return on restart and the car never acts differently with or without the error. Anyone else come across this? I live a significant distance from a dealer and am not eager to bring it in for no reason.

 

There is a TSB on this issue, it is a software upgrade

 

Thank you. I missed the previous thread where this was discussed. Sounds like the same issue. It's strange that it only appears after the car has set for a long period of time, but I've never been concerned as I've never had shift issues and the message goes away on restart. I'll bring it up next time I'm at the dealership.

 

We just picked up our CPO 2023 NX 250 a week ago, it has been -15C here and yesterday we got the same warning.
I checked the TSB and sure enough our VIN is included in the program..

 

Interestingly, the only time I receive the error message is after the car has set in the garage for a week or more. In the winter, it frequently sees sub-zero Fahrenheit temps and it's never shown the message. Thanks again for the help.

 

Got it again this morning. Car had been sitting for 48 hours and temps dropped just under freezing this morning. I definitely think it's a combination of both factors.

 

Fix may be on the way.
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I had this intermittent issue last winter on our 2023 NX 350. Similar conditions to most of you - after not operating for a few days and in colder weather, the car would display "shift system malfunction" after starting. Shutting the vehicle after warm up and restarting within a few hours, the display would not show the malfunction.

I took it to the dealer last winter. The malfuction was not present on the display when I brought it in, but I showed them a photo. They did find fault codes in the diagnostics unit. They reset the fault codes and said they could not take corrective action unless the malfunction was on the display.

I did not have the malfuction displayed all summer. In the fall, after long periods without operation it did appear a couple time. Now CT is in the middle of winter and it has got cold - the malfuction display is reappearing. So I schedules an early morning service appoint on a day forecasted to have low overnight temperatures and after not driving for two days. On the morning of the service appointment, the malfuction display appeared. When I arrived at the dealership I did not shut the vehicle off, and had the service adviser come out to see it. She attempted to have a technician come out, but determine that was not necessary. Coincidently, the regional service representative was going to be at the dealer that day.

When I picked up the vehicle, the service adviser had been told by the regional service manager that Lexus was aware of this issue and had been working on a solution. In fact, the regional service manager authorized the technician to perform a software update to the gear control module ahead of its release. So it appears a service bulletin is on its way to reprogramming the gear control module and correct this issue.

During the thorough troubleshooting of the gear system malfunction, they also found an open cell in the battery - replaced the battery under warranty. They also implemented the ECU software update to correct the cam shaft pin lock issue. Filled up the gas tank.

After after two cold days with operating the car, I did not have the shift system malfunction on the display after starting. Its been a couple weeks and we have not seen the malfuction display reappear. I was expecting this intermittent shift system malfuction would continue to be a gremlin that would not be corrected, but I am pleased with the correction and service I received at the dealer.

 

Thanks for the update. My service advisor also mentioned Lexus was working on a fix for it. Glad to see it resolved the problem.

 

Very helpful info, @JacksDad . Thanks for taking the time to go into detail.