Is anyone 100% sure of the actual process at the dealership when they "upgrade" a system..for example, when they perform the transmission TSB?

People mistakenly use the words software and firmware interchangably..but I'm curious which process is actually performed?

When "software" is upgraded, there is nothing physical (that can be touched/broken/stepped on/etc) being installed, but rather an OS which is downloaded onto some sort of non-volitile memory.

When "firmware" is upgraded, there is an actual chip or IC or something physical that is installed, and the old "chip" or device is removed.

Curious...are they just flashing a chip (software upgrade) or replacing a chip (firmware upgrade)?

 

The reflashing/firmware upgrade process involves reprogramming a micro-controller with new firmware. They call it flashing because the firmware goes into flash memory inside the microcontroller. Software is used to upgrade the firmware or at least this is the process I'm familiar with in terms of micro-controller hardware.

 

Ok, so let's take the transmission TSB for example.

Are they physically removing/replacing/etc a chip or IC and replacing it with another......OR.....or do they hook up a computer/laptop/etc to the vehicle and download/reprogram/reflash/etc the existing chip?

 

https://www.clublexus.com/forums/ls4...n-upgrade.html

I couldnt find the Lexus TSB PDF describing the TSB procedure, but I did come across the link above. It looks like it is just a firmware upgrade that fixes the issue. The firmware either has it hard coded in it the correct parameters to fix the transmission hesitation or the correct shifting parameters are loaded into another memory module where it is read. Im just guessing as to those parameters are set, but it should be somewhere in the code or saved in memory.

To answer your question, they wouldnt need to replace the chip and they are usually soldered in anyways. As long as the hardware works, all the chip would need is reprogramming with the latest firmware.