On my 2019 Prime Plus I sometimes get a voice prompt that says "SD Card Error" on a 10 second loop. Once triggered, the only way I know to clear it is to turn off the car, wait a few seconds for the infotainment system to shutdown completely, and then turn the car back on. Sometimes I could go days without triggering the voice prompt, but sometimes it could trigger 3 times in an hour of driving. The only SD card in the car that I know is the map data card for the navigation system. The voice prompt could come up while the navigation map is showing on the screen, and the map continues to work after the prompt comes up. The prompt could still come up with the map data SD card removed from its slot below the screen, with about the same random chance of triggering the prompt as when the SD card is in the slot. Rebooting the infotainment UI by holding down the volume button does not clear the prompt, which still repeats in a 10 second loop while the infotainment UI reboots. The whole SD card could be read on a computer without any error. Of course duplicating the card is a non-starter because of the unique ID embedded in each SD card. Does anybody know of a way to clear the prompt without having to shutdown the car? Or a way to turn off reading the SD card permanently? I don't use the navigation system so disabling navigation would be fine for me. Oh and the volume of the voice prompt is independent of the infotainment system volume, so won't go away even if the infotainment volume is turned down to zero.
The Repair Manual (more info) doesn’t mention such an aural warning; a problem reading the SD card used for navigation would be reported instead with diagnostic trouble code B158C, SD Card Communication Malfunction. I wonder if the source might be a dash camera or some other device installed in the car. I have a Toyota drive recorder (the DRD-H66, sold in Japan), and trouble with its microSD card is reported by spoken messages such as “SD カードを読み込みできません.”
Thank you @Elektroingenieur you might have solved the mystery. I do have a dash camera mounted that takes power from the lighter socket, and of course it does also have a microSD card for video recording. Turning off the car shuts off power to the lighter socket, and the dash cam shuts down once its supercapacitor has drained. That'll explain everything that I've been experiencing. Will check it out tomorrow when I drive the car again. Thanks!
It is confirmed the aural warning came from the dash cam, not from the Prius Prime. My dash cam is mounted behind the rear view mirror and normally I don't see it or think about it. Thanks again @Elektroingenieur! You've solved a problem that's bugged me for many months. I was even thinking of wiring in a switch to turn off the infotainment while driving, but that would not have fixed it. Thanks!
