That doesn’t sound normal to me, especially since it started right after the battery replacement. Disconnecting the battery can reset the transmission’s learned shift adaptations. Sometimes the transmission will act a little strange while it relearns, but that usually resolves after a few drive cycles.

The bigger red flag is the transmission temp gauge climbing and then suddenly dropping, along with it holding ~2000 RPM at 95 km/h until several kilometers later. That suggests it may not be going into its normal gear or torque converter lockup until later.

I’d ask the dealer to check for TCM/ECU relearn procedures or software updates, and also verify the 12V battery connections and grounds since the issue started immediately after the replacement. If it happens every cold start, I wouldn’t accept “that’s normal.”.

How many drive cycles have you had? What are ambient temps?

Thank you so much for your response. This has been an issue after replacing the battery. The first time I took the truck back they indicated that they reset the computer system. Further, the vehicle would have to relearn my driving patterns. Unfortunately, I drove it for 3 weeks and the issue continued to persist. Took it back again and they kept it overnight so that they could test drive it the following day when it was cold. They were able to duplicate the problem however: said they had another vehicle the same as mine and it did the same thing. I have had it back ever since and it continues not to shift and the transmission temp climbs and then falls. The dealership nor Toyota are prepared to do anything about it. I went so far as disconnecting the battery for a 1/2 hour but this did not do anything.

If the dealer was able to duplicate the issue, then that already proves it’s not just “driver learning.” Three weeks is more than enough time for the system to relearn.

The fact that it started immediately after the 12V battery replacement still makes me think something in the control modules didn’t initialize correctly. Simply disconnecting the battery again usually won’t fix that because some relearn procedures require a scan tool initialization I believe.

Two things that are odd Holding ~2000 RPM at ~95 km/h until the trans temp spikes The temp gauge suddenly dropping once it finally shifts normally

That almost sounds like it’s delaying torque converter lockup or staying in a lower gear until the system transitions to normal operation.

Personally, I would push the dealer to check for TCM/ECU calibration updates and perform a transmission adaptive relearn with the scan tool.

Verify the 12V battery install and ground connections since the issue began right after that service but it's probably not the issue.

It’s definitely not something I see widely reported.

I have made an appointment with another Toyota dealer in the area. While talking to the Service Department, they related that the issue is not normal. They will have a look at it next week. Thank you for your advice and I will update the post when it is repaired.