I love the DCI and it has worked amazingly for about a year now.

The other day I noticed the HU's (Alpine 9857) volume going up and down 1 step on its own.

Has this ever happened to anyone? I'm really puzzled why it's doing this.

The speed sensor is wired but disabled. The unit is nicely mounted and wires are soldered/sealed correctly.

 

Try unplugging the DCI(if possible with your install) and see if it continues to do it, this way you'll know if its the DCI or the head unit itself.

 

I have the same setup, except I've enabled the speed function. My HU did the samething one day. I turned everything off (with ignition on), then turned off car, and restarted. This seemed to clear the problem.

Good luck.

 

Yeah turning the HU off and on does clear the problem but it comes back sometimes. I just don't feel like digging in the console. Are these things ever defective?

 

I suppose they could be. When I first got mine, I could adjust the speed/volume setting to '9' rather than 8 (which is the published limit). This caused runaway volume. I contacted Modifry and he had me send it back. He updated the SW, and returned it. It's been good ever since.

He's very good about servicing and answering questions. Send him an e-mail describing your problem.