This is a very good vehicle with zero significant issues over the decade that I have owned it and done all of the maintenance specified in the manual. It's had a few preventive TSBs (one that I did myself, oil cooler line swapped out rubber for metal; one I let the dealer do, faulty windows switch that had not yet failed). But here are a few lazy fixes (remember, true laziness is when you never have to fix it again).
I had the issue that at random times, even without anybody or any animal near the vehicle, it would start the horn beeping, lights flashing INTRUDER ALERT. Eventually, I realized this is coming from a faulty hood switch, making the computer think that somebody is attempting to open the hood on a locked vehicle.
You need to replace the hood switch. The switch component itself is easy to extract from the hood latch assembly. Remove that from the vehicle and you’ll find
Then, replace the switch inside the holder, with Panasonic Electric Works ABS1413409 which costs less than $5.
You can find some very good articles on this online. Here I am talking about the stereo, non-navigation, with JBL audio system that came installed on my “Limited” edition Highlander. After 8 years or so, these stopped working, so the only way to adjust volume (left knob) or tune the radio (right knob) is with the controls mounted on the steering wheel.
The root cause is failure of the mechanical switch rotary encoder mounted on a small PCB behind each knob, caused by dirty contacts inside the encoder part:
It’s easy to remove these, simply pull the knob straight off (already done in the picture above) and then remove three screws, and finally unlock the flex cable connector to the PCB. The left and right PCB are identical but a different encoder is mounted on each one: the right knob has detents and the left does not. I chased down what I think are the part numbers, given the visual stamp on the part (shown above) clearly indicates the manufacturer is ALPS.
If you want to replace the encoders, which seems like a good idea, here are what I think are the ALPS part numbers. On the left knob: EC11E1534408 (20mm shaft, flat, no detent, 1.5mm travel momentary switch, 15 pulses (or EC11E1834403, all same except 18 pulses). On the right knob: EC11E15244G1 (20mm shaft, flat, 30 detents, 0.5mm travel momentary switch, 15 pulses). All available for $5 or so from Mouser electronics.
But you can be even lazier than buying new encoders, un-soldering the old ones, and replacing with new (some online references have people actually disassembling these $5 parts and cleaning the contacts, but in my view, that isn’t very lazy since you still have to un-solder the encoder). Simply dunk the entire PCB, encoder included, in isopropyl alcohol overnight, for good measure give the knob shaft a few turns now and again to help clean the contacts. Re-install and you are back in the saddle for another 8 years.