So my Gen 2 (don't know the trim package ... has 6 CD changer, bluetooth, and AUX input) has been exhibiting some very strange behavior. I've searched the forums and can't find anything that's quite like what I'm experiencing. The symptoms have also been changing, making it even harder to pin down. Symptoms: Audio: At first, I would get no sound for the first 10-20 minutes of driving, then sound would come on but I would be unable to control volume with either the knob or the steering wheel controls; that functionality returned 10 or so minutes after the audio returned and would gyrate wildly for a while before settling in. Now, the audio starts with the car, but I cannot control volume except for very spotty moments in the course of a 1 hr drive. I can change mode, station, etc, through the faceplate, MFD, and steering wheel. It appears to be the volume that is the issue. Radio reception: The radio reception is now very bad. Even with the sound off, I can see the "ST" flashing intermittently as the antenna finds what is ordinarily a strong signal in the city. When audio returns, reception is bad. Bluetooth: I have noticed that connecting to my phone is less reliable than it used to be. It now connects maybe half the time, and when it does connect, the microphone doesn't work. It seems like the audio works, but only when the radio works, though I haven't really tested this Diagnostic: I went through the MFD's diagnostic panel with the INFO + headlights method and saw the information in the photos attached. Basically, the amp shows NCON and there are a bunch of error codes that seem to correspond to loss of power to some component(s). This suggests that maybe I should replace the amp, but the weird behavior seems to go beyond the amp. I also checked the 12v and it's perfect. I had similar symptoms a couple years ago along with a very sluggish MFD that hasn't resurfaced, but it eventually went away. I haven't tried disconnecting the 12v (can't fit my ratchet in there!) and I'll give the volume knob trick a whirl, though this seems to be a bigger issue than the faceplate. Any ideas?
welcome! maybe a bad circuit board or something. just for fun, try disconnecting the 12v for a minute to reset everything.
I assume you have the JBL system? You can tell by there being a center speaker behind the center console screen. If there's a speaker, you have the JBL system, if not, you have the normal Prius sound system. I agree with bisco - a first step to try is resetting the car by disconnecting the 12V battery for a few minutes and then reconnecting. Might be a software glitch. All you need to disconnect the battery is 10mm socket. Disconnect the negative wire at the point it's attached to the car frame, it's much easier to disconnect there than at the point the wires are connected at the battery. If it was just the volume, it could be the steering wheel wiring. But with the codes and radio reception problems, it points to more than this. To me it sounds like the most likely cause is your CD player being bad. The second most likely cause I think is a wiring problem to your CD player and/or amplifier (amplifier if you have a JBL system). Third is a problem with the amplifier if you have a JBL system. I see two options - you could try swapping in a replacement CD player by getting a used one off ebay or a junkyard (be sure to match JBL or non-JBL to what your car has), or your could put in an aftermarket CD player. If you don't have a JBL system, I would definitely go the route of getting an aftermarket CD deck, as you can be sure it would solve your problems, will work with the speakers in your car and isn't a hard install. If you have the JBL system, getting an aftermarket CD player is more complicated as the speakers aren't directly compatible with them. This is a good thread on replacing the CD player (tells what wiring kits to get, etc.): Stealth install an aftermarket stereo in Prius | PriusChat You can watch this video to give you an idea of how hard it is to take out the Prius' CD player:
Thanks, @bisco and @Kevin_Denver. It is the JBL system.... should have mentioned that earlier. I disconnected the battery for a few minutes and I know it reset the system because all my settings went away. But, no luck. Same symptoms as before. Also, I checked the CD player and it is definitely putting out sound. It works like before, except that I can't control the volume. And I may need to revise about the radio reception. It seems like it's not as bad as I thought. So, next step is check the wiring behind the CD player? This looks like a pain. I did at least disconnect and reconnect the harnesses attached to the amp, but no change. Any chance there's a fuse issue? I pulled a couple but I wasn't sure which ones to pull or what to look for.
One more data point: the functionality of the volume controls appears to be related to temperature. The warmer everything is, the better it operates. Bad news as we head into fall.
Chance of being a fuse issue is virtually nil. Fuses either let current pass through them, or they're blown and whatever electronics is connected them doesn't power up. If there was a loose power wire you would see the whole unit come on and off at once, but that's not the case. Occasionally volume knobs can be fixed by rotating them a lot in both directions, which then scrapes the connectors together and cleans off corrosion. You could try for example turning the volume knob 50 rotations in each direction and see if it improves. Does the volume knob work okay to change the volume number if the amp is disconnected? This is worth trying as well. Otherwise I think the issue is most likely in the CD player or in the wiring. First thing I'd try is hotswapping another JBL CD player and see if it solves the problem. Maybe you can find someone on craigslist with a junked Prius who would let you try swapping one in before purchase. Otherwise it's possible to get a new deck for ~$100, new front component speakers for ~$100, and rears for $50 if you're okay with not getting too high end.
Well, the problem has just gone away. Much like last time, it just sort of resolved itself about a week ago and hasn't resurfaced. Hopefully it'll stick.
Just updating for posterity: the problem came back again in pretty short order. I decided to just buy a new amp to see if that's the problem. I picked a used one up on eBay for $45 and installed it (really not so hard). Problem has vanished and stayed away for at least a month. It was definitely the amp.
