Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

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coftedal
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Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by coftedal » Tue May 28, 2019 4:28 am

Greetings,

I have been working on installing my new Kenwood 995S for a good portion of the weekend, and I appear to be close, but at this point, I'm not positive if my RR Gen 1 is too old?

Some backstory:
I bought my RR Gen1 in the fall of 2014 when I bought my Toyota Tacoma 2015. I installed it with a Kenwood DNX891HD. I went through all the installation of military splicing the RR harness to the factory wires, bought a camera harness adapter that allowed me to use my stock camera and display rear view camera on my Kenwood head unit (this was independent of the RR). Everything all worked in harmony - my steering wheel controls were fine, I got all the gauges that were supported at the time, etc.

This past weekend, I decided to upgrade to a Kenwood 995S. I thought it would essentially be a matter of changing out the head unit, and flashing my RR to the latest firmware with the updated radio information. It hasn't quite worked out that way.

After wiring the Metra 70-1761 harnesses and hooking up the stereo and the RR (like I had done in the past) the stereo worked just fine, but the RR unit wasn't recognized by the head unit. I went through several rounds of resetting the RR (watching for the flashes and green success), and finally got in to the pattern where I could get the head unit to recognize it, but my gauges screen was just circles with empty data, and my tire information was just empty blue outline boxes. If I shut off the truck and started it again, my RR was no longer recognized. None of my SWI worked either. My next step after searching the forums was to buy the HRN-RR-TO1 harness. I removed my old, original RR wiring harness and all the military splicing that went with it, and proceeded to remove the Metra harness and rewire everything to the TO1. After going through this, I hooked everything back up, and it almost all works. My SWI is back, I have gauges (though my tires say N/A at the moment), and the biggest stumbling block remaining is that my rear camera does not show any picture when truck is put in reverse, or viewing the rear-view through the head unit - I just get no display at all.

Here's where I'm at:
I used the 4 wire camera harness that came with the TO1. I cut apart the custom camera harness adapter that I originally had when using the DNX891HD. That adapter was simply a plug that fit the factor plug (24 pin connector, 4 pins used) and were wired out to power, ground, and then a yellow RCA. I cut that apart and saved the plug, and then wired up the 4 RR camera adapter wires according to the schema shown for my setup (24 pin adapter) to that plug. I've re-checked these four connections numerous times visually for correctness, and also did a continuity check and everything has passed. When I put the truck in reverse, the head unit properly interrupts and switches to rear-camera view, but just black displays, no image. I've connected the two pin plug off the RR camera adapter to the corresponding RR connector. All of my other wires that I have checked through on the RR and Kenwood harness all appear to be correct - I can't see what seems to be missing.

So, I do have a few questions:
1. Does the TO1 support rear-view camera integration with a Gen 1 RR? I got to thinking that since my original RR wiring (even though flashed with the new head unit information) didn't "just work" until I switched to the TO1 harness, that there might be other incompatibilities?

2. In the RR directions for my Tacoma 2015 and 995S, it shows a 3 pin audio cable w/ 3.5mm plug connecting to the Kenwood unit in addition to the 4 pin data cable. On my Gen 1, I don't have that 3 pin RR port. I just have a 3.5mm plug port where that 3 pin port would be. So, I'm using the 3.5mm to 3.5mm cable that came with my Gen 1 to connect from the RR to the Kenwood unit. Will this work the same - are they functionally equivalent?

3. Would upgrading to a RR Gen 3 (I believe that's the current rev from what I can see on the forums) buy me anything in the way of features or support with this Kenwood 995S? I saw on the forums that sometimes the truck needs to be driven for the tire information to display something other than N/A. I'm not sure if that tire information was not possible on the RR Gen 1, or if it was a limitation of the DNX891HD.

My 995S has been flashed to the latest firmware from Kenwood's site. My RR Gen 1 unit is running the ADS 2.6 firmware. I've tried resetting the RR through the Kenwood head unit, but that hasn't seemed to change my situation.

I don't mind if I have to upgrade to a newer RR Gen 3, I'm just trying to understand if that is going to be required for everything to work, or if all should work just fine with the RR Gen 1 that I have now.

Thanks!
Chad

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billr
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by billr » Tue May 28, 2019 9:59 am

The Gen 1 RR would be fine since it let you select the Kenwood 995s radio. If that radio was not an option when flashing that would have been the sign that you needed a newer RR.
As for the camera not working, one thing to check is to see if you have 6 volts on the Blue/Yellow wire (camera power) coming from the RR when in reverse. This will let us know if that part is working right.
The TPMS, we get that info down at the OBD2 connector via the Gray/Red wire coming from our harness. So you should have a total of 3 wires at the OBD2 connector coming from the TO1 harness: Gray/Red (for TPMS info), Red/Brown, and Yellow/Brown (for the Gauges).
N/A means we do not see the TPMS system so if the Gray/Red wire is connected at the OBD2 then a reset of the RR may be needed. Just unplug all the connectors going to the RR, press and hold the reset button on the side of the RR, while holding down the reset button plug in the power connector (red, yellow, and black wires). Keep holding the reset button down till you see the led start flashing red, then let go of the reset button. plug in the rest of the connectors and retest.
the 3.5mm to 3.5mm cable is fine to use, we changed over to a 3 pin connector at one point but the function is still the same.
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coftedal
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by coftedal » Mon Jun 03, 2019 12:37 pm

Thanks for the info, Bill.

I thought I'd post an update here. I decided to go ahead and purchase a Gen 3 Maestro. I know you said the Gen 1 would work (and I do appreciate that), I just thought since I had everything torn apart, it'd be a good time to do the upgrade anyway. It's a lot of work taking all of that in and out of the dash, and I thought I might as well make the most of my time. With the Gen 3, when I hooked everything back up, my TPMS "just worked" as in I now get psi and temp. My gauges were all there, and I really like the updated look of the gauges and layout. Happy camper there, money well spent.

Regarding the backup camera. I tested the Blue/Yellow wire for camera power, and it's only sending 4.98 volts, not the (I believe) 6 required to turn the camera on. I'm not an expert on the OEM camera, and in my searches on the Toyota forums, I've seen folks mention by 6v and 12v. When they mention 6v, they almost always are referring to or working on a truck that has the reverse camera output up in their mirror. They say they need to step it down to 6v. My truck is a 2015, and the rear view display for that was in the Enture head unit. I have no display in the mirror at all. I found one post that claimed they thought the cameras that outputted to the head unit were 12v cameras. I just don't know the official specs. It seems unlikely that Toyota would have a different camera for the head unit vs. the mirror, but I just can't say.

So, what I did was keep the video on the RCA cable that came with the TO1 harness, and I moved power and ground (i.e., I don't use the blue/yellow wire on the TO1) and this is how I had it set up with my old radio. I do get an image now, but it is almost scrambled looking. You can sort of make out what is behind you, and you can see the reverse guidelines, but the picture is pretty distorted - reminds me back in the day of a scrambled cable channel that wasn't a part of your cable package. You can sort of make out the image, but it's not usable.

Overall, my situation has improved, but if you had suggestions/ideas on the rear camera video (why we're only getting 5v instead of a minimum of 6) and why the video using the RCA cable is displaying distorted, that'd be great.

Thanks!
Chad

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billr
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by billr » Mon Jun 03, 2019 3:03 pm

Chad,
make sure that the adapter you are using for the camera has the video (+) wire (yellow on the rca) going to the Red wire in the truck and the Black wire of the video rca to the White wire of the truck.

Does the 5 volts ever change when you switch from reverse gear to any other gear? Or does it stay 5 volts no matter what?
William (Bill) Repicky
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coftedal
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by coftedal » Mon Jun 03, 2019 4:58 pm

Bill,

I can check the voltage here for you shortly. I'm 99% sure it didn't change, but I'll confirm that for you for sure.

Regarding the video, did you mean to say the brown wire instead of the black for the second connection? In my wire chart for Step 2, brown is for video (-), and black was for ground.

Thanks!
Chad

coftedal
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by coftedal » Mon Jun 03, 2019 5:27 pm

Bill,

I just checked now on the voltages. I got 4.94v with the truck in park idling, and 4.95v in reverse with my foot on the brake. This is a Tacoma 2015 4x4 quad cab w/o JBL.

Thanks,
Chad

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billr
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by billr » Mon Jun 03, 2019 5:39 pm

coftedal wrote:
Mon Jun 03, 2019 4:58 pm
Regarding the video, did you mean to say the brown wire instead of the black for the second connection? In my wire chart for Step 2, brown is for video (-), and black was for ground.

Thanks!
Chad
If you are using our harness with the rca then yes, the Brown wire would be the video negative or shield.
William (Bill) Repicky
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by billr » Mon Jun 03, 2019 6:08 pm

do this chad, I just posted a new firmware to your account to use. Pull the RR out and connect it back to the computer. when you reflash the Maestro there will be a "Flash by User Firmware" tab, select that and in there will be a new firmware to put on the RR. enter the rest of the info like you did originally.

now for the wire harness, you need to do one change....the Blue/Yellow that currently is power to the camera, disconnect that. Find the Yellow/Black wire in our wire harness (probably just taped up, wasn't used during the initial install), connect the Yellow/Black wire to the power wire of the camera (the wire that the Blue/Yellow was originally attached to).

Let me know if that fixes it.
William (Bill) Repicky
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coftedal
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by coftedal » Mon Jun 03, 2019 9:02 pm

Hey Bill,

OK, downloaded the firmware and set it up as you described.

With the vehicle off, 0v out of the yellow/black line - as expected, I'm sure.
With ACC on, 6.12v
- Tapped the HU for camera view, and I had an image on the screen. So, the camera definitely powered up with 6v. My image issue is still there, though I didn't expect that to change
With truck running and in reverse, 6.15v
- HU automatically switched to rear camera view, and again I had an image. Like before, has the distortion, as well.

So, that test flash definitely now activates the camera properly, and that yellow/black output worked great.

Thanks,
Chad

coftedal
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Re: Maestro RR (Gen 1) w/ Kenwood 995S, no rev camera display

Post by coftedal » Wed Jun 12, 2019 2:33 pm

Just to update and close the loop here. I finally resolved this issue last night.

- I ordered a plug-n-play camera harness w/ 12v to 6v step down for my Toyota Tacoma. That eliminated the RR harness completely from the backup sequence, as well as any possible wiring issues I could have had with my old adapter. When I hooked it up, I still had the garbled image.

- I ordered a new replacement OEM Toyota backup camera off of Amazon. It was the camera only, simple plug-n-play drop-in replacement. I was down to either the wiring from the camera to the head unit having an issue, or the camera itself. With the new camera installed, I have a perfect picture. Problem has been solved.

I suspect at some point and time, the old camera got a mis-wired signal and that did it in. I would have thought it would have zapped all image, but apparently it was enough to put it in this in-between state.

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