2012 Civic SI Premium Audio System w/ Navi Problem

Shadyrester

Member
7
1
Hello All,

Just joined the forum today, have a problem with my SI's sound system that I'm wondering if anyone else has experienced and can recommend a solution or troubleshooting method. Here goes...

Even with the sound system head unit turned off, loud and uncontrollable static just starts to erupt from the speakers. You're driving along and out of nowhere it sounds like bullets are hitting the windows and there's a lightning storm going on inside the car.

In the engine compartment fuse box, I've pulled the fuse for the power amp and all is quiet. Unfortunately, no music either.

As I've mentioned, this static presents itself even with the head unit turned off. That being said, is there audio signal generated from the navigational system when the radio or CD is off? Even if you haven't input any trip information into it? I'm kind of at a loss as to how best to pinpoint the origin of the static.

I'm thinking that disconnecting the head unit's input harness at the power amp and reinstalling the fuse would be the way to isolate the power amp during its operation to see if the static problem is created within the power amp itself. Will this work, or is there possibility of messing up Body Control Module operation or the Anti-Theft system? In disconnecting the input harness, is there a turn-on trigger wire that would be getting disconnected which would keep the amp from powering up?

Anyone experienced this problem with their premium sound system? If yes, could you please share your fix? Any and all advice appreciated. TIA.
 
I’ve seen other comments (on other car forums) where this has happened, and 3 individuals found that their stock amplifier was at fault for the static/pops/bangs they heard even when their radio was turned off. I’m guessing the amp is getting power even when the radio is turned off to provide gps voice guidance and whatnot.
 
I just read your post again and realized you did pull the amp fuse and that resolved it. The fact that others said the amp was faulty, and you having success with pulling the fuse, I’d say you may need to find a stock amp on eBay, or maybe check junkyards for wrecked civics?
 
I just read your post again and realized you did pull the amp fuse and that resolved it. The fact that others said the amp was faulty, and you having success with pulling the fuse, I’d say you may need to find a stock amp on eBay, or maybe check junkyards for wrecked civics?

Hello,
Thanks for your input. I'm in the process of searching the used market. I'm leaning toward the power amp being the problem here, trouble is that pulling the fuse on mine is not a conclusive test, as that just keeps the problem from being audible, it doesn't reveal the source of the problem. That, along with the unknown of what might possibly be wrong in the head unit or navigational system.

If I disconnect the input harness from the power amp, is there any aftermarket harness available to temporarily connect the head unit to another power amp that I have on hand to facilitate testing? I'd like to avoid cutting the factory wiring.

These premium system OEM head units and power amps aren't cheap, even as used. I'd really like to buy the right fix first time.
 
To bypass the factory amp, you need an aftermarket amp that takes differential balanced inputs. There are a limited number of amps out there, but you can find some. There is a wealth of info in this post explaining how to bypass the stock amp.

http://9thcivic.com/forum/threads/2013-civic-premium-audio-system-navigation-stereo-upgrade.10207/

Also, I see there is at least one factory amp for sale on eBay for like $95 I think it was. You could even send a private message to the person who started that thread I linked above. Maybe they still have their factory amp they could sell you for cheap.
 
Thanks again for the advice.

In my locale (BC, Canada) wreckers are quoting $550 and $350 CAD respectively, for the head unit and power amp, plus taxes and shipping.

The one on eBay for $95 came out of a 2015 and apparently isn't compatible with the 2012 SI Navi head unit, for whatever reason that might be. I will investigate that further to verify.

I will follow up with the leads provided. Thanks again.
 
They pop up from time to time. I'll keep my eyes open for you

For $550, I'd tell the wreckers where they could stick their equipment
 
Hello again and thanks for the continued posts and information. The full part number of my power amp is 39186-TS8-A511-M1, from the label affixed to it. I managed to get my phone up under the dash and snap a picture of the label.

The part number posted in an earlier post is pretty close, though not identical.

As far as compatibility, I mentioned earlier a power amp on eBay which came from a 2015 SI Sedan. part #
39186TR6A110M1.
The compatibility tool on the ad listing indicated it wasn't compatible with my 2012 SI Coupe, no reason specified.

Can anyone comment on possible compatibility / incompatibility with this unit? Were there changes to the sound system during that time period that resulted in design changes to the power amp used in later cars?

Thanks again.
 
Last edited:
Just an update and FYI on things...

I'm currently in discussion with Jesse at Phantom Audio on getting a fix for the system.

He advises me that the power amps are different between the SI Coupes and Sedans, which is good to know. He didn't specify what the differences were, but I don't need to know. It's just good knowledge to have in order to keep away from the cost, time and effort involved in going down the wrong path. Thanks Jesse.
 
The radios changed during the 2012-2015 span, so it’s likely the harness plugs changed. It makes sense the amp part numbers changed as a result. The guts are probably identical, but the harness clips changed.
 
So to provide an update, here's the latest developments...

With advice from Jesse at Phantom Audio, I purchased a used power amp which came from a 2015 Civic EX sedan, which was compatible with my 2012 Civic SI coupe.

I did the swap, re-installed the power amp fuse in the engine compartment fuse box and once again I had my sound system back and working. However, the next day, the ballistic static returned. Arrrghhh!!!

That's the status at the time of this writing.

So, still unsolved, what is the source of this static. To recap, the static is intermittent, random, very loud, and distracting. It happens without warning, even with the radio/cd system turned off. My thoughts are that the Navigation system may be the source, as it is always active, and uses the sound system to provide voice direction. Is there a separate module under the dash which contains the Navigation system, or is that all contained within the radio/cd head unit?

Once again, any tips and advice greatly appreciated.
 
When it happens, have you ever run the fade/balance from left to right and front to back to see if every speaker is playing the noise? Unfortunately, there isn't a separate device that contains the nav. It's in the head unit itself.
 
When it happens, have you ever run the fade/balance from left to right and front to back to see if every speaker is playing the noise? Unfortunately, there isn't a separate device that contains the nav. It's in the head unit itself.

Update:
So now with the power amp fuse installed to enable sound system operation, I have no audio, no static either. I wasn't able to test the balance and fader controls before this condition presented itself. At this point, I don't know if the head unit has completely failed for audio output or if the used power amp I installed has gone bad. The Navi screen all works, the radio and CD info displays. just no audio.

I have been searching around for a head unit, but I would like to be reasonably sure of finding one compatible with my vehicle. It may be that since my vehicle is from the Canadian market it may complicate things as far as part numbers and such. My head unit has an ID code under the ENTER knob at the bottom right corner of the face, it reads 9AC4. I have found a head unit from a 2012 Civic EX-L which looks identical as far as all the buttons go and the Premium Sound System label above the CD slot. It has an ID code of 9AC2. Anyone know what these ID codes mean as far as compatibility and interchangeability? Will the 9AC2 work for me?
Thanks for the help and advice so far.
 
12 Sedan si nav part #
39541-TR0-306
Shows only compatible with the si nav trim

2FE617E1-52A6-4766-BE7A-D944543712B3.jpeg


12 coupe si nav part #
39541-TS8-305
Shows compatible with ex nav, ex-l nav, and si nav models.
521268BE-ED4D-4E22-9E5F-19A18664B62F.jpeg

From what I’m seeing on eBay the 9ac4 is found in the 12/13 si. I see some 9ac2 models claiming they came out of an ex nav model, but they didn’t specify coupe/sedan etc or if it had premium audio.


You may be able to compare pinouts from this to what you see for sale?
http://9thcivic.com/forum/threads/2012-civic-audio-wiring-guide-pinouts-for-factory-radio.5916/
At the end of the first post it has a link to the non premium radio pinout in that thread.
 
Back
Top