New member, audio issue

[TRCobra506]

 

[TRCobra506]

Cool.

High level overview.
Apim has stereo and mono signal outputs. Stereo audio signals are sent to the Audio Control Module (this is The module with The C.D. player in it. The ACM relays this to the Digital Signal Processing (DSP) module. This is in the trunk. The DSP powers the speakers, takes care of volume, speed comensaing volume and other fun stuff.

For mono signals the APIM sends this directly to the DSP.

Since your radio (am/fm) is inoperative it makes me think that there is a stereo signal system fault. Meaning ACM, circuits (4 to me exact left high low, right high low) then the DSPs. DSPs tend to be a common failure point. Have to verify if there is input to the DSP from the ACM looking for A.C. voltage.

I tried to read up on the different mono and stereo signals but I can't easily find this on my cell phone.

C4236A pins 7 and 17 are left (green grey). 9 and 19 (Violet and yellow) are right channel at the d.s.p. this connector is long rectangle 20 pins large. Measure A.C. voltage at 7 and 17 and see if there is a signal. It's not common for both left and faith fail at the same time. I see a lot of DSPs failing. But make sure and don't make a guess. The module is not plug and play.

No AC voltage at these pins

 

[TRCobra506]

So these pins are analog out of the ACM to the DSP? Does the APIM send a digital signal to the ACM that it converts to analog?

 

[Johnbigdog]

No. Not that I'm aware. The A.C.M. is a pass through.

I don't think there is a digital audio signal until you get to a lot newer audio systems with an automotive audio buss. This is a fancy name for a u.s.b. cable. But even then I'm not sure.

So one would have to work back to the A.C.M. on the passenger side kickpannel there is a large black 59 pin connector that those wires pass through. Your going to find those wire colors in 8,9,10 and 11.

C240A at the ACM behind the FCIM will be a black 24 pin conector. Pins 10 & 22 left, and 11&23 right. Colors are all the same. You can back probe the ACM connector with a sewing pin to see if there is output.

If there is no output, the radio isn't "on" or the box is possibly bad being you can select stuff (am/fm/satellite) but nothing happens.

Still doesn't quite explain your other concerns.

 

[Johnbigdog]

Just so we are on the same page, that is the A.C.M.

 

[TRCobra506]

Just so we are on the same page, that is the A.C.M.

Yep we are on the same page. That’s where I back probed for the AC speaker output to the DSP. Pretty solid 0v

Cd will act like it’s playing but also no output from the ACM. I would assume the the APIM has nothing to do with playing a cd other than telling the ACM to select it as an audio source seeing as how the CD is in the ACM itself.

Stab in the dark must be the ACM? The FCIM was disconnected and connected for all these tests. No change in symptoms. All modules disconnected and reconnected, no change

 

[Johnbigdog]

You are correct that a c.d. does not go through the APIM. The ACM sends this out to the DSP.

 

[TRCobra506]

Well the time has come to buy an ACM or try the stealership for a firmware update with explicit instructions not to touch or replace anything

 

[Johnbigdog]

It would be helpful to see if there are any DTCs present. A new module needs programming so it may be a dealership visit anyways.

 

[TRCobra506]

Theres no DTCs, I have a snap on modus. Nothing weird in the data either

 

[Lostneye]

It would be helpful to see if there are any DTCs present. A new module needs programming so it may be a dealership visit anyways.

Or forscan.

 

[TRCobra506]

Or forscan.

I might be able to program it if it’s needed, maybe. Sometimes in functional tests I will have those options. I can program OEM keys with the last update I received

 

[TRCobra506]

ACM fixed it, no programming necessary. On another note. I found out this is a pre production car. Built in 2011

 

[Johnbigdog]

Saweeet!


If you got a used part, it was programmed. If it's new.... I don't have a good answer.

 

[TRCobra506]

Used part, pulled from a 2013 limited. No programming for sure. I use this yard a lot and they had none of my cars info. But happy it works!

Sounds good. Is there any info about pre production cars on here? Car came from Detroit, going to run a carfax on it and see what it says. Every piece has pre production written on it vin ends in 00134

 

[Johnbigdog]

With swapping parts, your ESN for Sirius satellite radio changed. If you had an active account, you may not any more.

I don't know about the preproduction thing.

 

[TRCobra506]

Yeah no previous subscription, it hasn’t worked since I got it haha. Well carfaxed it. It was built a year before it was first titled. Built November 2011

 

[2011TAURUSSEL]

Since you have gone that far in tearing apart the center stack perhaps you wouldn't mind one more step. The Center instrument panel speaker the 3.5" Pretty much anything besides the OEM one will help. I used Kicker myself but your discretion. Make a note with a decent three way speaker the center voice coil will be ABOVE the level of the grille. Solution is to get a couple of thin washers, 2 anchor clips and two self tapping screws and install the speaker UNDER the plastic. If you are interested I might still have some photos of mine from about three years ago. There is also a VERY SMALL amount of trimming of the plastic but it will be UNDER the grille and in a non visible area.
If interested PM me email address and I can try and dig them out.

 

[Lostneye]

Used part, pulled from a 2013 limited. No programming for sure. I use this yard a lot and they had none of my cars info. But happy it works!

I guarantee the yard didn't program anything. There isn't a ton that needs to be programmed in the ACM and being it came form a Ltd which is the highest trim level besides the SHO it probably had satellite, Sony, already.

 

[Sgtmeatsauce1]

OP I have a 2013 PP SHO, It was doing the same as yours, they updated my pcm for 100 bucks, this took care of the problem for a year...now it is doing it again, no sound on radio but other sounds ok, ac comes on by self etc. Usuall if I restart my car 3 or 4 times it goes back to normal. When it does not I unhook battery then hook it back and do a battery relearn, then it ok for a few months again. Now my right passenger door speaker comes and goes, sometimes is not as loud as the others or has static. This is the third speaker. So it not the speaker, I have all new POLK speakers and a Kicker for the bass in rear. When the system works it sounds pretty good.....