Beeping while driver side door open

[CTScott]

Originally Posted by CoryM

Not sure how the Yaris key reminder switch is wired, and oddly enough the online manuals are missing that page, but I think you will find the switch is grounded and it thinks there is always a key in the ign. May be as simple as spraying a little lube on the key to free up a stuck switch. Again, no idea how the Yaris switch looks so can't advise further, other than to try unplugging the switch if possible.
Cheers.

That's actually a good idea if he doesn't find an aftermarket wiring issue. The key reminder switch is a small plastic pin switch that is mounted just below the ignition switch on the steering column. It has a two pin connector with a yellow and white/black wire.