04 MFD MF-ing Failure - Diagnostic Steps

[cheeze]

I was installing GROM (non Vline) bluetooth/usb integration unit this weekend. Pulled the NAV/radio unit out, making sure to break all the wood trim clips along the way. I leaned the NAV on a side and atop the shifter and plugged everything for initial testing. Worked great. Even named the bluetooth hookup "SEXUS" (don't steal that). I unplugged and re-ran the cables.

Upon re-test, I got:
"Check Connection to the Air Conditioner"
AUDIO OFF
No Nav
No Climate, but temp setting, auto, defrost works
NAV/MFD nightime illumination works, but not for the radio power knob, nor any of the lower audio controls

Some research pointed me here, so I went into diagnostic mode, cleared the memory and reset the codes. No dice. I went to home depot for some contact cleaner and retried. Still dice-less.

I should note that in between the first successful test and the unplugging and subsequent failure, I unplugged the battery to do an HID install. I don't think that had anything to do with it failing but is a possibility.

Plan of action is to:
- check fuses (which ones in particular?)
- check wiring (how the hell...)
- start looking for repair places
- drink and scowl hoping to seem like in deep thought
- anything else???

My hunch is that a fuse or capacitor has rendered the bottom portion radio blown and is causing a domino effect with the NAV and AC. The fact that there is no illumination, nor power to the bluetooth unit points that way. It would really suck, however, if they were each their own, unrelated problem. I really want to avoid sending it in for repair as it'll eat into my lift budget.

Will someone point me to an 04 NAV/ML audio wiring diagram?


I had no idea 04s were susceptible to this. My family has had 2 04 LSs with no such issue.

 

[Hoosier Daddy]

So to clarify, you are having this failure WITHOUT the Grom plugged in? Just the factory setup, right?

Seems like the simplest explanation would be an incompletely seated connector or bent pin. I'd triple check the connectors before proceeding in any other direction.

 

[cheeze]

So to clarify, you are having this failure WITHOUT the Grom plugged in? Just the factory setup, right?

Seems like the simplest explanation would be an incompletely seated connector or bent pin. I'd triple check the connectors before proceeding in any other direction.

The failure was noted when I unplugged the GROM unit and replugged it once I tucked some of its cables away. The unit only goes to the CD player section of the MFD unit and I did not unplug any other cables. The MFD did sit leaned against something for about an hour or so, so maybe a wire got loose behind the pin (ugh fack).

I think you're right in that its the simplest explanation. I'm not sure about the bent pin however as the male and female sides are very tight. I'll have to check it once more with a fine tooth co

 

[HomersCanyonero]

I think Hoosier is saying to get it back to stock configuration without any of the Grom connections in place. This way you can get it working back in stock condition.

This way u eliminate the Grom from causing any problems. After it’s working in stock configuration, then connect back the Grom.

 

[cheeze]

Yes. Once I realized there was an issue, I went back to completely stock. Same problem. Went into service mode and reset. Same problem.

 

[Hoosier Daddy]

I think you're right in that its the simplest explanation. I'm not sure about the bent pin however as the male and female sides are very tight. I'll have to check it once more with a fine tooth co

The reason I mentioned a possible bent pin was because when I installed my Bluetooth unit a couple years ago, the pins on the aftermarket wiring didn't align well with the sockets on the factory wiring. I had to individually bend the pins until they fit better. The whole thing was so fiddly and tight, it seemed way too easy to get pins bent out of proper position.

Good luck getting it figured out. Hopefully it's just something simple.