Fixing the Mazda 2 AUX jack

So my 2010 Mazda 2 started to act up on me a few months ago – At first I had to jiggle the Aux cable a few times to be able to switch to Aux ¬†input, but after a whiIe I had to use one hand to hold the plug in at just the right angle and another hand to press the Aux button on the control. A bit difficult to do while driving…

As it turns out, this is actually a common problem in Mazda vehicles, caused by their use of two pins to detect the insertion of the jack. The pins are supposed to be shorted out when the jack is inserted but after a while the pins wear down or get loose and the stereo is not able to sense that an AUX cable has been inserted. According to this YouTube video, the solution is to short out the two pins permanently, so here goes…

First, we have to open up the console. Press in and pull up the front of the console:

This will reveal the cables connecting to the lighter and the auxiliary (AUX) port. Carefully pull out the connector for the Aux port and note the wires connecting to the Aux connector. On my car, there were five wires: pink, black, white, red and green. The middle black, white and red wires presumably carry the audio signal while the pink and green wires are used to detect the insertion of the plug.

According to the video mentioned above, pins 2 and 6 have to be shorted, but note that that video refers to a US (?) Mazda 3 and other forum posts mention different pin numbers for other Mazda models. So, first thing to do is to check which pins to short. I just used a short length of wire to short out the pink and green wires and confirm that I could now select AUX using the control button.

VERY IMPORTANT ! The method I used is a destructive method so be very, very sure that you have the correct wires before cutting them.

I cut the pink (#2) and green (#6) wires and shorted them together. In retrospect, I think the green (#6) wire was actually ground and shorting wire #2 (pink) to ground is probably the signal to indicate insertion of the Aux plug. It would have been smarter to cut the wires 1 cm away from the connector and use a crimp connector to short the pink and green wires together so that it would have been easier to reverse the process, but that’s 20/20 hindsight. This is what I actually did: I just cut the pink and green wires, stripped a little bit of the ends and wrapped them together.

After putting everything back together again, I am now able to switch between radio and AUX using the button and even though I cut the green (ground ?) wire there doesn’t seem to any static or other interference so far.