Aftermarket unit issue 6 years later

Alright gents, you're my last hope. In 2014 installed Pioneer AVH-X8500BHS into my 2010 Tahoe with Bose analog amp with RPO UQA using Metra's harness, ADBOX1 module, and ASWC to retain factory controls. All was working fine up until 2 months ago when factory backup camera stopped engaging in reverse. Charging polarity setting does nothing. Camera works if manually turned on in HU. Steps taken:

1. I took everythig apart and checked every connection; all is wired properly.
2. Reset Metra modules, updated Metra ABDOX1, and reprogrammed; no charge
3. Replaced Metra ADBOX1; no change
4. Put factory DVD/NAV all is working as it should
5. Connected factory backup camera to a TV running running of 120v, shifted into reverse, camera turned on.
6. Connected AV source to HU backup camera input, shifted to reverse, and no image (this source has constant 12v)

After replacing ADBOX1, I now get white noise when activating backup sensors or on HU boot. Same results with old ADBOX1. I am thinking it is a ground issue somewhere, but upon checking for continuity between HU chassis and vehicle body I get steady tone on my multimeter so seems to be fine. Everything else in the HU works fine, so might not be ground issue. No codes with Tech2 other than ECM B1000 and OnStar antenna open circuit. I am running out of options. If the HU is at fault why is everything else in the HU works...

Seems like you covered your wiring. I wonder if it’s simply the camera itself? I wonder if you could get a free camera from somewhere just to try.

Also, I wonder what would happen if you disconnected the battery for awhile? Maybe some sort of glitch that can be remedied by a reboot?

Jason in DLH said:

Seems like you covered your wiring. I wonder if it’s simply the camera itself? I wonder if you could get a free camera from somewhere just to try.

Also, I wonder what would happen if you disconnected the battery for awhile? Maybe some sort of glitch that can be remedied by a reboot?

Click to expand...

Doubt that it is the camera. As mentioned in step 6 above, I connected AV source (front camera) and still no result.

Have you checked the resistance between the camera connector ground and the HU connector ground, while the connection is apart? Any potential there? Some meters will sound continuity below a certain number of ohms above zero, so you may want to measure for a number.

You'd need a long test lead, but what about any potential between the ground at the camera -- if there is one -- and the HU, again with the connection apart?

EDIT: if that checks out I would suspect the center pin connection on the HU camera input, or possibly the HU itself (an internal component).

Fless said:

Have you checked the resistance between the camera connector ground and the HU connector ground, while the connection is apart? Any potential there? Some meters will sound continuity below a certain number of ohms above zero, so you may want to measure for a number.

You'd need a long test lead, but what about any potential between the ground at the camera -- if there is one -- and the HU, again with the connection apart?

EDIT: if that checks out I would suspect the center pin connection on the HU camera input, or possibly the HU itself (an internal component).

Click to expand...

I will check. Am I looking for absense of resistance? Also, what would cause camera to work manually? If the center pit is at fault, why would it work manually?

The harness / wiring between the hatch and body is about the age to degrade and cause an open or short.

Wiring is tricky and keep in mind that condensation and temperature plays into the solution sometimes. Being that all was fine up until now seems like a run out on the wiring somewhere.

I’d escalate the issue to a known auto electrician. Experience takes precedence on oddball issues like this.


Sent from my iPhone using Tapatalk Pro

petethepug said:

The harness / wiring between the hatch and body is about the age to degrade and cause an open or short.

Wiring is tricky and keep in mind that condensation and temperature plays into the solution sometimes. Being that all was fine up until now seems like a run out on the wiring somewhere.

I’d escalate the issue to a known auto electrician. Experience takes precedence on oddball issues like this.


Sent from my iPhone using Tapatalk Pro

Click to expand...

Why would it work with stock radio?

TahoeLT10 said:

Why would it work with stock radio?

Click to expand...

It all points to a defective component in the HU. You've substituted several known good sources, and the issue seems to be when the backup "sense" is activated. Being able to have it work manually, and from other sources, is the clue.

Fless said:

It all points to a defective component in the HU. You've substituted several known good sources, and the issue seems to be when the backup "sense" is activated. Being able to have it work manually, and from other sources, is the clue.

Click to expand...

Yeah, that's what I am thinking but was hoping it wasn't the case[emoji3526]

TahoeLT10 said:

Why would it work with stock radio?

Click to expand...

I don’t know. Without a meter to run down and over a schematic, it’s impossible to diagnose in a discussion. If it were possible to exchange the current Pioneer for a known working Pioneer, that would answer a few questions.

There’s no substitute for a good auto electrical / stereo shop but they’re hard to find.


Sent from my iPhone using Tapatalk Pro