Stereo out

Get a radio from a wrecked Prius Two? Just a thought.

 

My radio was inactive this morning. No sound at all on any of the available channels. I pressed the power button in for 5 seconds and it reset the radio. After that, the radio worked just fine.

 

Sorry it didn't work.

 

Check to see if the fuse is blown?

 

By “stereo has gone out,” I’m assuming you mean that no sound comes from the speakers, but the display and touch screen on the head unit seem to be working. I’m also assuming that the problem happens even if you select AM or FM as the audio source, so it’s not specific to Bluetooth, and that you haven’t installed an aftermarket amplifier or made other changes to the car’s electrical system.

For the symptom “No sound can be heard from the speakers,” Toyota’s Repair Manual (available by subscription to techinfo.toyota.com, and possibly through your local public library) suggests first checking the audio settings—volume, fader, and balance—which I imagine you’ve already tried.

@Adam1a's suggestion to check fuses is reasonable, but I don’t think a blown fuse is likely here (※). The head unit receives 12-volt power through three fuses, all in the Instrument Panel Junction Block Assembly (described as “Left side instrument panel” on page 631 of the Owner’s Manual): RADIO (15 A), ECU-ACC (5 A), and ECU-IG1 NO. 4 (10 A). If one of these were blown, the head unit probably wouldn’t work at all.

The Repair Manual next suggests checking the speaker circuits; it says, “If there is a short in a speaker circuit, the radio and display receiver assembly detects it and stops output to the speakers.” Enter diagnostic mode on the head unit, and then select Failure Diagnosis, System Check, SP Check On, which should play sound from one speaker at a time. If you identify a faulty speaker, the Repair Manual explains how to check the wiring and speaker assemblies; note that some of the speakers are riveted in place.

If the speakers are OK, the Repair Manual recommends replacing the head unit (in Toyota’s terms, the Radio & Display Receiver Assembly, part number 86140-47270), which has no field-serviceable internal components. Before doing this, I’d first try installing the latest software update (per T-SB-0279-17) and, if it wasn’t done while diagnosing the speakers, removing and re-installing the existing head unit, to force a complete reset and make sure the connectors are all properly seated.

If you decide to replace the head unit, you might take a chance on one from eBay or, as @Prodigyplace suggests, from a junkyard. A Toyota dealer would arrange for an exchange or return-to-depot repair by Panasonic (1-800-423-8150). I don’t know the cost, nor if Panasonic or their service center, United Radio, accepts repair orders directly or if you have to go through a dealer.

If you do involve a dealer, and you’re not far past the 36,000 mile warranty limit, you might ask them to seek goodwill consideration from Toyota for at least part of the repair cost. Sound systems shouldn’t wear out.

(※ A blown fuse could well cause this symptom on a Prius Four or Four Touring with the optional JBL amplifier, which is powered through a dedicated AMP [10 A] fuse in Engine Room Junction Block No. 1.)