Does any know the difference between the part number 89661-24313 and 89661-2431384 or what the 84 means in general. Can’t seem to find any information on this. Thx.

 

usually that means Toyota/Lexus revised the part number at one point, where the longer number replaced the shorter number part. That’s true here and you can see if you search the longer name part at Lexuspartsnow.com…

Lexus 89661-24313-84 Reman TCCS Computer

1993-1995 Lexus 896612431384

• Part Description
  Control Module
• Replaces
  89661-24313
• Manufacturer
  Lexus

 

The "-84" addition onto any Toyota part number (usually for anything electronic such as an ECU) is just there to denote that it's a factory Toyota remanufactured part. It is exactly the same thing as the same part bearing the main number *without* "-84". Toyota just took some of these original parts, remanufactured them (via re-capping, testing of whatever chips they want to and giving them presumably some kind of final QC testing process that the reman part passes in order to be sold in inventory).

A revision part number doesn't involve the "-84" addition. A revision would be like 89661-14320 being the original ECU which is then superseded later by the revised part number 89661-14321... or a final revision of 89661-14322. A revision is always just a change to the very last number in an ECU part number. Same ECU compatibility if so listed in the Toyota/Lexus system (or our big list of SC ECU part numbers from everyone's submissions over the years) but in those cases Toyota did indeed do something or other to update a chip or something else either with a small programming or small reliability refinement.

Then even later you could see revisions of any ECU part number but usually not the very first ones. Using those same example ECU P/N's you would theoretically see in the wild:

89661-14320-84, 89661-14321-84 or 89661-14322-84.

Apply this breakdown methodology to whichever ECU P/N is specific to your SC. I hope this helps!

 

Good clarifying info, Kahn! Often I’m buying used parts and get a little hesitant when the official part number is off by a digit like this. This is the most likely explanation.