The volume up control suddenly stopped working the other day. All the other controls still work fine, including volume down. Stereo has been installed for about a year with no issues, problem popped up out of the blue.

The volume knob on the HU itself of course works fine. Its just the dash control that is not working.

I have a Pioneer HU, and using the ASWC-1 'steering wheel' controller. That device decodes the digital signals feed to it over a single wire from the stock dash controls, then controls the HU via signals sent to a 3.5 mm plug on the back of HU.

Since its all digital signals from the dash, through ASWC and to radio, it can't really be any of those components. Either they'd all work or none of them would. So I'm thinking it has to be the actual button switch on the dash itself.

The dash volume rocker switch is actually just two adjacent push button switches. Its only a rocker switch mechanically, as the plastic switch 'knob' just teeter tooters on a pivot, and therefore can only depress one of the volume buttons at a time.

But before I tear open dash to replace the switch (if I can find a new one to solder to the PC board, otherwise I'll have to find a used dash circuit board), I wanted to see if anyone else has ever seen a dash control button fail (and if they found a source for new button, would rather have button on hand so I only have to open dash once). Or if anyone has any different diagnosis to rule out.

 

On other cars i know of with failed buttons it is more typically the button itself. You can test that part of course when you get it open. But do not rule out the controller completely. If the firmware in it is relying on a look up table to send commands to the headunit (I have never dug into those designs and thus am not sure how they are doing it) and somehow that table was corrupted (bad portion of memory or something else) then it can literally be sending the wrong command for one function and possibly still work for the others. This is less likely to be the issue and not be affecting other functions, but is still possible. I have encountered a lot of issues in years of electronic product development that seem improbable but occur :P

I am leaning more towards the button itself being the issue though. For what you are experiencing, a mechanical failure of the electronic switch is most likely. You may be able to clean the switch depending on its construction. That would be the best outcome. I expect there are simple dome buttons under the rocker switch, and the carbon or metallic connection inside the dome may be corroded or worn away.

 

Yes, good point. First step should be trying to see if I can spray some contact cleaner in the button (if I can, I'll do all of them while its apart). I'll be able to confirm with certainty if the switch is faulty, and if cleaning fixes it, using a multimeter, while I have it apart.

I did LED bulb replacements when I did the stereo, a year ago, and so I had dash apart then. IIRC, the buttons weren't those metallic domes, nor those carbon rubber overlays, but rather discreet through hole mounted traditional switches. Should be easy to replace one if I can find an equivalent part online someplace.

I'd just prefer to have the part first even if cleaning can fix it. So I only have to take it apart once. But that means figuring out what part I need first. Hoping someone knows.

 

I had a similar failure. I bought a replacement control module to swap in. When I got my old one out I took it apart and found that there is a little rubber pad in there that had moved out of place. I moved it back into place and it worked fine! Now I have a spare module.

 

I have the same problem just developed. I wonder if I gave ot a 'smack' with my knee getting in and out being a tall bloke.
You can clearly feel a 'click' on the volume down still but the 'click' has disappeared on the up stroke as it were! This clearly points toward a mechanical failure in the switch. I can buy a used panel on an 'on-line auction' for £15 so for the price I may as well have both options available, when I take it out.
Anyone have any tips images for removal please??

Many thanks Lee.