Originally Posted by phattyduck

Back up lights are powered from the GAUGE fuse.

That fuse also power such things as:

ABS
Air Conditioning (Manual A/C)
Automatic Air Conditioning
Back−Up Light
Charging
Combination Meter
Cruise Control (3RZ−FE)
Cruise Control (5VZ−FE)
Electronically Controlled Transmission and A/T Indicator (3RZ−FE)
Electronically Controlled Transmission and A/T Indicator (5VZ−FE)
Engine Control (3RZ−FE)
Engine Control (5VZ−FE)
Front Wiper and Washer
Headlight (w/ Daytime Running Light)
Key Reminder and Seat Belt Warning
Light Auto Turn Off
Multiplex Communication System
Rear Differential Lock
Rear Heater
Rear Window Defogger and Mirror Heater
Starting (3RZ−FE)
Starting and Ignition (5VZ−FE)
4WD (w/ 2−4 Select SW)
4WD (w/o 2−4 Select SW)

Sounds like it is more likely the switch on the trans that went bad...

-Charlie