Been trying to find the answer to this for a long time ?
One of you guys must have had this TSB done . Check your service records using your Vin # and it should show you what the software upgrade did . Here is the link where you can check what has been done to your truck http://www.toyota.com/owners/web/pages/home
I punch in the information here but the pdf doesnt load http://www.revbase.com/BBBMOTOR/
Dont know where else to look without pleading with a Toyota tech to spill the beans