This is about the strangest thing I've ever heard of. A customer with a Pioneer Wired DCI sent me an email saying his system is doing strange things. In all of these emails the customer says these strange symptoms ONLY occur if the DCI is plugged in, with the DCI removed everything works fine. He also says he has checked the wiring and everything is correct. His story isn't always consistent but I'll summarize it this way:

First email:
1. With key in ACC position, unlocking the trunk causes the Pioneer head unit to restart
2. With the car started, pressing the trunk buttons does NOT cause a restart of the Pioneer HU
3. Sometimes starting the engine causes the Pioneer HU to restart
4. Removing the DCI "fixes" the above problems.

My response - OK, a bad DCI could cause a Pioneer HU to restart. While the "power" command is not in the DCI's normal repertoire , it's possible a broken DCI could send a on/off command if something is hosed up. But what's up with the trunk button? That sounds like some major wiring issues. I also told him the HU restart when cranking is normal but I didn't understand why it doesn't restart EVERY time, as HU power is interrupted whenever the starter is cranking.

Next email:
1. Whether the car is running or not, pressing the trunk button restarts the head unit (different symptom than first message)
2. Sometimes when starting the car the Pioneer HU takes 20-30 seconds to power up.
3. When driving, pressing MUTE or Vol Up or Vol Dn causes the Pioneer HU to power down and not restart for another 15-20 seconds.

You think the above is weird - wait till you read this:

Last email: Customer installed the OEM head unit along with the DCI (don't ask me how or why)
1. OEM head unit restarts when MUTE is pressed
2. Vol Up and Vol Dn do not work.
3. OEM head unit restarts when the trunk button is pressed
4. All of the above symptoms go away if the DCI is removed.

I'm completely confused. What the heck does a DCI have to do with the OEM radio? The OEM radio doesn't even have a remote on/off command, so it has to be a power problem, but power doesn't go through the DCI and I can't even think of a way where power could be routed through it without it turning into toast.

What could be going on?

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OK I'm hooked.

This is WEEEEIIIIRRRDD! I am not sure how the OEM trunk release works, but most are switched ground circuits, I think.... When the button is depressed, completed circuit, the actuator/solenoid is triggered.

I have absolutely NO idea how this would tie into the power of a HU....

Interested to find out!



John

 

All these things sound like a short or wiring problem....especially the HU taking 15-20 seconds to restart.

I would want to see detailed pictures of the wiring.

 

Does he mean he hooked the stock HU up with the dash buttons (referring to the stock connection as a DCI) or actually hooking up the DCI to stock HU?..... Which seems impossible. I think I saw his post on here last week or a few days ago. It sounds familiar but it wasn't your post. Hmm. Good Luck.

 

While I am far from an expert, having installed my own Pioneer head unit with your wired DCI, the first thing I would do is isolate the power and ground they are using for the headunit. What would cause any headunit to restart? A sudden drop in voltage or ground problem I would guess. Wire the head unit direct to the battery and ground it someplace direct and I bet it stops doing it. Something is buggered in the factory harness and/or the trunk switch.

 

I am not sure a weak ground would cause it to short out and restart like that... I thought a loose ground would just invite EMI into the unit, which would be very obvious...

w/Jano, though... Is he positive he tapped into the correct wires for the DCI behind the dash? Also, how exactly did he plug the Wired Pioneer DCI into the back of the OEM HU? I thought the plugs were completely different...

I had something similar happen to my Alpine HU when I had a loose neutral to one of the door speakers (caused the HU internal amp to "reset" everytime the neutral came in contact with a surface ground). This might also sort of explain why the unit resets whenever the trunk-pop ground circuit is completed.... Maybe this circuit is touching some of his speaker wires?



John

 

hey, send me a free DCI and i'll see if the same happens for me

 

I am thinking it is a week battery or bad power connection. Popping the trunk may be causing a voltage sag that either the DCI or HU sees. Could also be a bad trunk latch solenoid that pulls to much power - with the car running there is enough power from the alternator to mask it, with the engine off the battery voltage drops or spikes low.

I would have him connect a multimeter to the IGN and ACC voltage going to the DCI and the HU with the car off and see if he can detect a low spike or sag when he hits the trunk latch.

 

I am thinking weak battery or nbad voltage regulator too... do lights dim on the car when these things happen?

 

Where is the guy located? Perhaps an EJ in the area could check it out.