Aux audio jack repair

At some point along the way, Toyota started installing an auxiliary audio jack in the center console of the 4th gen 4runners so you could plug in your ipod to the sound system, via headphone jacks (3.5mm plug). Mine started going intermittent on me a while ago which was really annoying when listening to my podcasts during my commute into work. Evidently, I'm not the only one because a quick google search revealed lots of complaints on various toyota forums, not just 4runner specific forums.

The fix is a $75-100 replacement for what amounts to about a $1 electronic part. Incidentally, there's also a TSB that came out in Aug of 2007 for excessive audio noise when the MP3 device is plugged into the charger and sounds system at the same time. This is TSB AU004-07 (see attachement), "Noise from auxiliary port with external device" and it affects 06-07 4runners, Prius, Rav4, 07 camry, camry HV, FJ cruiser, solara, and yaris. It shows the previous part number 86190-53010, which is the part that broke in my 4runner, and the new part number 86190-48010. According to the TSB, these are the same part numbers for the Camry CBU (whatever that means), FJ cruiser, Prius, Rav4, and Yaris. It also looks like there is a filter that goes inline, but I'm unsure of the part number since I didn't actually do the TSB.

So, not wanting to spend $100 on a stupid little part, I decided to take it apart and see what's wrong and hopefully fix it. Usually what happens is the solder joint breaks on a circuit board and just needs to be remelted. Using a magnifying glass, I didn't see anything wrong. So then I thought maybe the spring contacts in the jack needed to be bent back into shape, especially when I pulled up on the plug, it would work again. That didn't work. Finally I decided to unsolder the jack from the board and really take it apart and see what makes it tick.

http://antinode.smugmug.com/photos/i...-vgD5qcb-L.jpg

To do this right, I really needed a solder sucker to properly unsolder the contacts, but I didn't have one so I made due. This resulted in a couple Oopsies. I ended up breaking off one of the prongs and delaminating one of the traces from the circuit board. Delaminating the trace wasn't so bad, because it ended up that I didn't need it anyway for this fix (more on that later). The broken prong was bad because I did need it so I ended up jamming a piece of wire in there and soldering it all together.

http://antinode.smugmug.com/photos/i...-gTVrnxB-L.jpg

There were a lot of pieces but luckily, most things only go in one way or it's easy to figure out where it goes.
http://antinode.smugmug.com/photos/i...-rRktWwc-L.jpg

So this is what turned out to be the problem. The plastic clip had cracked in half.
http://antinode.smugmug.com/photos/i...-Lp4SJ2m-L.jpg

The reason this is a problem is best explained when one understands what the circuits are doing. What happens is the radio is looking for a signal from the jack telling it whether there is a plug plugged in. If there's no plug, then it'll switch to the CD player mode. If there is a plug, the it'll switch to the "Aux" mode.

The middle contact acts as a 3 way switch. When there is no plug, the contact is normally closed with the top contact in the picture below. This tells the radio there is no plug. When there is a plug inserted, the plug pushed down on the black plastic piece and it in turn pushes down on the middle contact, opening the top circuit and closing the bottom circuit. This tells the radio there is a plug inserted.

http://antinode.smugmug.com/photos/i...-8nLSg5b-L.jpg

Because the plastic clip broke in half, it could no longer push down on the middle contact and the radio would intermittently turn off the Aux mode and revert to CD or since I didn't have a CD, it reverted to the radio.

To fix this, all I did was bend the middle contact down so it always remains in contact with the bottom contact. Of course, this means I can no longer use the CD player, but who uses CDs now-a-days anyway? This is why I didn't need that trace that delaminated; it's the CD circuit.

After all was said and done, I soldered it back together, reinstalled it, it's almost good as new.

nerd alert!

love it :)

so how much time did you spend total on this? just trying to figure out the cost / hour ratio vs the $100 to get the new part. ;)

but I have to admit there's no way I would want to spend $100 for the part so I'd probably end up spending a good 40 hours taking it apart, researching and finding a fix so in the end I would probably say the $100 is worth the time and energy but that's $100 out of my pocket! no way I'm donating $100 to Toyota for a $1 part!!! lol go figure....

hate being a garage mechanic sometimes.... such is life!

I think probably 2 hours. I messed with it a few months ago so I knew how to remove it from the center console, which is a piece of cake. Half my time was spent inspecting everything and trying to figure out how it works and the other half was spent trying to unsolder the prongs without the proper tools. Figuring out that the plastic clip actually plays a role in how it works was the key to everything.

Now, I could probably do it in less than 30 min including removing it from the console and gathering the tools. I could justify spending $100 if it were something big and steel, but a stupid piece of plastic just pissed me off, ya know.