I just picked up a 2012 G37s sedan with Bose, no Nav. The radio sometimes works, other times it doesn’t. When it’s not working, the volume and tuning do nothing, just turn. If I turn car off and let it sit, sometimes it starts working again. So is this the head unit or the Bose amp that needs replaced. It’s so random. There are day it works all day. I did the self diagnostic and codes were AV COMM Circuit 39 and Handsfree Unit Connection Error.

Thanks

 

When the radio is NOT working are the control changes appearing on the screen (volume change graphic and station info)? If SO, it would point to the amp as being the problem. If NOT it would indicate something going on with the head unit. I don't know what the error codes mean but somebody in here probably does.

 

The "39" is not a code but rather a counter/ as in the number of times a error was detected in circuit "x." From the FSM:

However, none of the above has anything to do with the Bose amp and your lack of sound. The Bose amp is not connected to the AV COM lines. Now, whether the BTHF device is interfering with the sound is a possibility -you may want to consider disconnecting the BTHF module and see if the sound issue recurs.

Best advice, next time this issue occurs, immediately run the diagnostics and perform the "Speaker Test." You can also check for proper power/ground voltages at the amp itself (including the AMP ON 10V+ signal).

 

[QUOTE=13_SkylineSedan;4303293]When the radio is NOT working are the control changes appearing on the screen (volume change graphic and station info)? If SO, it would point to the amp as being the problem. If NOT it would indicate something going on with the head unit. I don't know what the error codes mean but somebody in here probably does.[/QUOTE

When it’s not working, the volume bar shows on screen but does not move with the ****. Same with tuning, station shows up, but does not move or change with ****. So this sounds like I need another head unit?

Thanks for the quick reply👍🏻

 

I started a speaker test but there was no sound coming from the first test so I stopped it. This was during a time when audio wasn’t working. Should I just let the rest run even without sound?

Thanks👍🏻

 

Good point by ILM, it's possible the bluetooth hands free phone unit is interrupting your audio - as if a call is taking place. Any chance there is a min:sec timer clicking away on screen when you lose audio? That "TEL adaptor unit" is mounted below the rear window deck and accessed via the trunk. Pic below is from the '13 FSM. What I don't know is if the system will function normally with that unit unplugged, but that would be worth a try.

 

I don’t recall seeing a timer but next it does I’ll look closer. I do have a Bluetooth adapter plugged into cig lighter to stream music from phone to radio. Could that be causing the issue? I'll unplug that item above and see what happens.

Thanks

 

Radio was not working his afternoon. Unplugged the TEL item in trunk and plugged in again with no change. Also ran speaker test. Nothing happens, just stays on left front tweeter. Here is video of me turning the ***** and nothing happening. Also a pic of the speaker test.

 

Wow, that is weird behavior. It actually senses that you are moving the volume control but then doesn't take any input from it. I've never run that speaker test but it says "push start to test next speaker" so I guess you have to manually step through it? Also, no timer so the TEL unit has not seized the system as if there is a call coming in. I suppose it could be related to your bluetooth adapter and I'd suggest removing that to eliminate it as a suspect. But even if that was somehow taking control you should still be able to adjust the volume and other audio functions. Super weird.

I'm out of ideas but maybe ILM or one of the audio experts in here will have some more.

 

Do the steering wheel buttons work? ie... does the volume indicator actually move?

What is the connection status when you enter the Diagnostic Menu? Sample image:

Based on the behaviour in your video, I would venture to guess that your headunit is starting to give up the ghost.

​​​​​​​I would disconnect your adapter and also disconnect the BTHF module in the trunk. Leave it disconnected and go from there. If the problem persists, then go from there.

 

All the items on the diagnostic screen show green, no issues found.

The steering wheel controls do not work either when this happens. Again, it’s random. One start up and everything is fine. Next one either few minutes later or hours, nothing. Then sometimes just turning car off and back on again fixes it.

 

There have been reports to where wireless phone chargers caused interference with the switch panel. While similar to your issue, I'm curious if your Bluetooth streaming setup may be the cause of the non-responsive system (see thread).

I would suggest you completely disconnect your setup, or at the very least move it as far away as possible from the center stack, and see how the system behaves. Wouldn't hurt to disconnect the BTHF module in the trunk as well (OK to keep disconnected for this test). If the issue persists, all I can guess is that the headunit is on its way out. Perhaps others will have other ideas.

 

Ok, I’ll take out the BT adapter and unplug the one in trunk and see if problem continues.

Thanks and I’ll report back

 

Update: the issues continued after removing the BT device and disconnect of the BTHF. So I order another head unit from a 2012 G37. Came with a 1 year warranty so I'll get installed this week and see if that corrects the issue. Thanks for all the help and ideas.

 

Thanks for the update. Friendly reminder: be sure to disconnect the battery before you replace the headunit.