Kenwood Head Unit won't turn off when connected to OBD

Hey all - weird one for the experts on here. Kenwood DDX6706S head unit that was installed in the truck back in Sept 2019. I've had the OBD connector attached for the last couple of years and haven't had any issues at all...until yesterday.

Had a dead Compustar remote start system replaced with a new Viper setup, and at pickup, the guy mentioned they were confused by the OBD cable and that the radio wouldn't turn off without them disconnecting it. Weird, as it had been working the last couple of years just fine.

Anyone have any suggestions on what it could be? There must be some power flowing back to the deck to keep it on, and unplugging it does work. But otherwise, full power to the Kenwood at all times (obviously not ideal!). I'm going to be adding some stuff in the next couple of months that will require me to remove the deck anyway and I'll check it out then, just hoping I can maybe get some ideas of what I should be looking for.

I'm unfamiliar with the DEI remote start units, but I'm wondering if they have a tie-in somewhere to the OBD system that may have changed something vs. the Compustar.

 

That’s weird. Not exactly sure how they did the install? Why was it working fine with compustar and not this? are they the same installer that did the compustar?

can you go into the maestro setting in the radio and change the obd connection from the Auto to something else? Maybe that somehow got change to Always Enabled.

 

The experience the last few months has been odd, for sure. I'll explain more below, but for now I'll check the settings and see if there's something weird there.

Compustar - truck came with it, no idea who installed it. I'm guessing previous owner, as Compustar had no record of it and there were some standard things missing, like the hood switch (standard on installs for safety).
Viper - installed by a local dealer (well known, no concerns there)

So I'll try to keep this brief, but...no promises

Compustar came with the truck and worked fine for the first couple of years (it had a Sept 2017 production date on it, so far from an old unit). The last few months it started acting wonky and requiring multiple button pushes to actually do anything - 2/3 presses to lock/unlock, remote start, etc. Over a couple of months, it progressively got worse and worse to the point where it was requiring 10-15+ presses to do anything. Eventually, it just up and stopped working at all. Felt like I was in Bedrock manually locking/unlocking the doors and running out to start it with the key as my new not-so-remote start.

Went through all the basic troubleshooting - new remote batteries, new remote, etc. Nothing changed or got better. I bought a new factory key fob and programmed it, so at least the last couple of weeks I've had keyless entry again.

Went through all the suggestions from Compustar on troubleshooting...I could never get either remote programmed. I could get the unit into programming mode, but could never get either (old or new) remote to be recognized (anyone need two assumed good Compustar remotes?).

Also - last week, the reverse camera (my install...I have to look at the wiring yet) started acting weird...when backing up it looked good for about 5-6 seconds, then it would get all scrambled. After a few days it started scrambled and then went black. Now, it's just black (i.e. no image at all). I'm not sure if it's related or just coincidence. I installed two bright LED reverse lights and thought it might be related, but replaced the old bulbs and same issue. It's an Amazon purchased Natika backup camera, so maybe it's just junk, though it does have a 2-year replacement on it if it is broken).

So yeah, it's been an interesting/frustrating couple of months from a "get my 2011 into the next decade" push.

The positives: replaced all the interior lighting with brighter LEDs and love it (includes the cargo, reverse and license plate lights as well).

 

Very strange indeed. The reverse cam seem like a coincidence and the cam is pretty much dying. I would get a replacement since it’s under warranty.
I still don’t understand how the obd is back powering to keep the radio ON.
How many wires coming from the obd to radio?

 

That makes two of us! I just ran out there to take a look and try a few things I'd read online - verified the OBD settings were not set to always enabled; verified the PIDs...same results. Had to unplug the OBD.

There are three wires running to from the Kenwood to the OBD port.

 

On your obd plug. It have 2 wires on top row. In the 2nd and 3rd hole from the left. And 1 wire on the bottom row, 2nd from the left?

if so, that’s correct for the pids and obd2 data communication. Weird that it’s keeping the radio On.
Have your unplugging the battery negative terminal for a full reset? To see if that does anything?

 

As of yet, I have not. It's a little cold today but I'll see if I can take a better look at it over the weekend and see if that helps. It's certainly weird it just started with the Viper install, so there has to be something related. I'm going to scour the manual to see what the Viper may be tapped into (engine settings, etc, that may be tied to somehow providing a power loop).

That sounds right for the wires. When I get out there again I'll snap a pic. I meant to but forgot...though I did get a picture of the current firmware version on the Maestro. I'd never dug into the settings there before...there's a LOT of stuff I wasn't aware was in there!

Firmware: ADS-RR(SR)-TY01-DS
Version: 03.20

 

You may have to pull the radio out and get to the maestro. Then do this mod. Adding in a diode to the resistor. Look specifically at post #14 and on. I dont know specifically which diode. But that seems to fix the issue.
https://www.tundratalk.net/threads/serious-problems-with-new-head-unit-and-idatalink-maestro.755437/

diode
Install Bay Diodes 1 Amp 20 Pack -D1

$5 Install Bay Diodes 1 Amp 20 Pack -D1, Black

https://www.amazon.com/dp/B0068AEU0W

 

I have read about that in places, but I also found this (for a 2016 I believe) about removing the resistor in the Maestro wiring. Someone had posted asking about a similar issue on the iDatalink forum and this was their recommended fix. I'll have to get in there when it warms up a bit next week and see which scenario I'm dealing with.

 

Pic is from this thread, if it helps: http://www.12voltdata.com/forum/viewtopic.php?f=404&t=19714

 

Try each and see which works for you. Curious to see what you find out later. Good luck.

 

So... The plot thickens. Realized yesterday on my way home my mic for the HU no longer worked. Figured out they must have cut or broken it during installation. So now, who knows what else they may have done...

Reconnected what was left I could pull out easily and got it working for the time being, so at least I can use my phone while driving if needed. Dash is currently partially apart, figured it wasn't worth putting back together until I get the mic and the OBD issues figured out.

 

Oh boy. Hopefully nothing worse.

 

Almost forgot...the VSC button was disconnected as well. I'll have to crawl up under there and make sure the connector was just pulled off on the backside and nothing worse. When I popped the trim off to pull the head unit the button just kind of flopped out...

 

Man. I hate that for you. It gets frustrating when you put your trust in the installer and they go and do things like this. If you can, definitely take your time and carefully comb through their installation. Make sure nothing is cut or left loose.

 

Yep, especially because I do 99% of this type of stuff myself, but the lifetime warranty and lack of special tools to do the programming means I'm limited in situations like this. Gonna have to check everything for sure. I won't even mention the bent plastic tabs I found

 

Definitely some rush job and doesn’t care bout details.

 

No special tools required. You can use the USB cable that comes with the Maestro and hook it up to any computer, download the Weblink software, and program these yourself. Just did it twice myself. Now if you’re talking the Viper remote start, I’m clueless on those. I use Fortin remote starts and those program very similarly to the Maestro units.

 

He’s talking bout the remote starter. Which i feel the same. I have no tool to program those either. So i, too, went with fortin for an easy plug n play application.

 

The power issue happened to me as well
when installing the alpine head unit in my 2019. As someone mentioned above, the OBD backfed the head unit and kept it powered on for some reason. I called alpine who referred me to maestro. When speaking with them it was a known issue and I had to bypass the resistor. It was an easy fix but made me very nervous. Haven’t has any issues since.

 

Found out on the way to hockey tonight they disconnected ALL the buttons on the lower panel, not just the VSC. Good thing I don't really need them, but man... What a hack job.

 

As mentioned above, talking about the remote start. The Maestro is easy enough as you said, and I've got the cable to program the actual truck stuff as needed (new key, new fob, etc.).

 

Were you posting about that on Maestro's forum by chance?

I'll get to it...as soon as I get all this other stuff fixed and reconnected lol

 

Okay - so I had the time yesterday to pull out the trim pieces and dig around behind the buttons to at least find and re-connect the connectors. They had pushed them up and out of the way while they were working, so it wasn't as straightforward as just finding a loose hanging plug on the backside...but anyway, the buttons are all fully functional again. So, essentially, with that and the cobbled-together mic, everything "works" once again, so that's a bit of a relief.

They did apologize and ordered a new microphone for me too, so in the meantime I'm leaving the middle of the dash essentially apart and will maybe tackle that resistor in the next day or two to see if I can keep the vehicle info without keeping the head unit on full-time.

 

Glad no other failure came from their hack job. This is why we have trust issue. We want these so called “professional” to do a good job and let their work speaks. But works like these are what gets them to loose business.

 

Picked up my new mic yesterday...haven't installed it yet but at least I've got it ready to go.

So, random but related question if anyone might be able to help:

I got my two new keys and new key fob all programmed up last night - my hope was to use the retractable key fob I got as my "normal" key and fob to reduce some of the extra clutter of carrying around separate pieces all the time. Key works fine - starts the truck, does everything it's supposed to. Fob works fine, locks/unlocks and works for the remote start as well. Here's where the catch comes in:

If I remote start the truck with either of the OEM fobs (not truly OEM, but essentially the same thing), I get the confirmation on the Viper remote and it seems like the system them locks out anything but the Viper remote. I can't lock/unlock or shut down the truck with the OEM remotes. I'm guessing it's a security feature of the Viper system to avoid code-grabbers, etc., but it's kind of a bummer that my plan here is sort of foiled. Using the key/fob I wanted, if I ever remote start the truck, I'm back to manually unlocking the doors to get in and/or turn it off. I can do all that still with the Viper remote...but now I'm back to carrying TWO remotes just to get all the functionality I'm looking for. I just can't win with this!

This is the key I got. It's getting closer to my dream of a fully keyless experience...kinda sorta lol

 

Yeah. Once you use the remote to start it the viper module will not let you use the oem fob to unlock. You have to use the viper remote.
I have viper remote starter on our rav4. It does the same thing. Oem key fob wont work.
Do you not have the plain oe key? That way you only need to carry the viper remote and key only. No need to carry around two fobs.
I have the fortin remote on our sequoia and i dont even carry the oem fobs anymore. I use the fortin remote and just the key. I have the extended miles 2way receiver for the remote.

 

I have:

OEM knockoff fob
OEM knockoff combo (shown above)
Viper LED
Viper backup

Long story short, my original actual OEM fob and backup key went "missing" during my divorce (along with the power cord for my laptop and cable for Techstream). So I was down to a single key and 1 (of two; #2; also went "missing") Compustar remotes.

I was hoping to slim it down as the factory key + any fob = a fairly full pocket, hence the retractable key fob was appealing. I think I'll still use it during the summer, as I rarely use the remote start then and it's not as awful fumbling for the physical key to unlock the door when it's not -30 out

From the reading I've been doing, the inability to open the doors with the OEM remote, as well as the engine shutting off when a door is opened is a Toyota standard for "safety". There's several threads here about how goofy of a system it is.

And yeah, I have the 'master' key and while I was programming all the new stuff last night, I deleted all the old stuff, just to be safe (line Toyota) LMAO

 

That seem strange your viper didnt come with it own sets of fob. not a bad idea to clear all the old key registry. No need for it and you can always program new keys.

 

No, it did. Sorry - the list above is the four fobs I have. The Viper came with the LED primary and a backup remote.