JD7

Tried what you suggested but no luck. Pulled out 30A Radio1 Fuse (under the hood on the passenger side) for 5 minutes. Turn on Nav Unit and it went to where it left off from last use (i.e. no change to Nav Unit). Override still doesn't work and all stored memory information is still there (i.e. I didn't lose any phone numbers or addresses stored in Nav Unit). Does the unit have a backup battery built in? And, do you think that the new 8.1 software that was loaded prevents overwrite back to v5.1? Please note taht I didn't eject my disk before pulling the fuse. I did eject my disk afterwards and verified that the Nav Unit states "No Nav Disk." My Nav Disk is DVD Navigation Map North America U20 86271-33045 464210-0660 DATA Ver. 05.1 and it does have a loading.kwi file that is 51,010 Kb from 01/29/2005 5:16 PM. Also, I still have the "I Agree" screen coming up at start up. Even after the dealer installed the v8.1 disk and ejected it and reinstalled my v5.1 disk the "I Agree" screen still came up although I lost the override capability. Still need help!

I have a 2006 Lexus SC430 with a Gen4 Navigation System with a 5.1 map software disk - fully capable of Overriding the GPS Motion Lock (Volume Screen Method using upper left, lower left, upper left, lower left ---> press & hold Override). I recently went to the dealership to have the software upgraded to 8.1 per the card everyone received. After reading that the Motion Override is lost in v8.1 I called the dealer to stop the upgrade. Unfortunately they had inserted the upgrade disk and some or all of the OS upgrade was completed. They put my original v5.1 map software back in the car and took back the v8.1 disk and refunded the upgrade fee and now I have v5.1 maps and NO MOTION OVERRIDE CAPABILITY. IS THERE ANYWAY TO RESET THE NAVIGATION UNIT COMPUTER AND RESTORE MY v5.1 OS (SPECIFICALLY THE LOADING.KWI FILE) AND MAPS FROM MY ORIGINAL v5.1 DISK TO REGAIN THE MOTION LOCK OVERRIDE CAPABILITY? I've read in some posts about disconnecting the car battery with mixed success, others have mentioned disconnecting a battery in the Nav Unit in the trunk, and others have mentioned both. 1) Is it possible to reset the Nav unit; and if so, will the v5.1 OS (specifically the LOADING.KWI file) reload to regain Motion Lock Override Capability? 2) What is the safest way to do this? 3) Are there any other adverse affects to the method suggested in response to question 2?