2005 Prius Park Button Backlight

The replacement lamp is shown in parts catalog Figure 84-01, Switch & Relay & Computer, in image 4, item ④, part name code 84480B. The part number is 90010-01061, list price $5.86.

The Repair Manual (more info) doesn’t seem to include procedures for the P Position Switch (also called M11, Main SW, in the Electrical Wiring Diagram). From a seller’s photos of the switch assembly (84480-47020), it seems the cap for the lamp—in the photos, the circular brown part—screws into the underside of the switch assembly. I don’t know if there’s a way to get to it by extracting the switch assembly from the instrument panel from the front side, or if you have to take apart some of the instrument panel.

In the latter case, to reduce the risk of inadvertent airbag deployment, disconnect the negative (–) terminal of the auxiliary (12 volt) battery and wait at least 90 seconds before starting work. Use the Repair Manual procedures to remove the no. 1 instrument panel register assembly, the lower and upper instrument panel finish panel sub-assemblies, and the no. 3 instrument panel register assembly.

That one is an LED, according to the Electrical Wiring Diagram, but your point is well taken.

 

AFAICT, the panels that need to be popped off don't involve any disturbance to the airbag system (as long as you don't mess with random electrical connectors you find down there). The "no. 3 register assembly" is the silver panel that the park button is in, but the "lower and upper finish panel sub-assemblies" (plastic panels to its left, upper one having the power button) overlap its left edge, and the "no. 1 register assembly" (the one at the left end by the driver's door) overlaps those, which is why it has to be first to be popped out.

I recently had to change the illumination bulbs in the power button, park button, and shifter of a 2009. I'm guessing the previous owner used to keep the dash dimmer set pretty high. It seems to make a big difference in how long the bulbs last.