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2011 - OEM rear view camera / CP635U1 HU research!

('09-'13) 
114K views 55 replies 26 participants last post by  SVXdc 
#1 ·
Several people have asked about interfacing the 2011 OEM camera to an aftermarket HU, as well as connecting an aftermarket camera to the OEM CP635U1 HU.

Hopefully we can determine how the OEM camera works so we can answer those questions.

SVXdc said:
Some 2011 Forester models have the OEM Clarion CP635U1 HU:
Vehicle Electronics Car Technology Multimedia
(Subaru Part No. 86201SC630, Clarion Model No. PF-3302B-A).

This has a 4.3" color screen, used to display a rear camera image (as well as showing expanded info for radio, satellite, MP3s, and iPod).

Rear of HU:
Electronics Technology Electronic device

More pictures here: New OEM Radio Installed into MY11 WRX: Source MY11 Forester

Pin-outs of all of the rear sockets on the CP635U1:
Text Diagram Plan Technical drawing Drawing

Here is Subaru's wiring diagram for the camera: View attachment 2011 Forester RearView Camera Wiring.pdf

As you can see, the wires run straight between the HU and the camera. There are no connections to anything else in the car. That means the HU provides power for the camera.

Link to Subaru's installation instructions (pdf) for the H001SSC700 camera kit. All work is performed at the tailgate. There is a pre-installed factory harness that runs up to the HU.

This Clarion CP635U1 HU uses the same style of 8-pin socket as the OEM Kenwood Navi HU (the one with the full-size touchscreen, found in some 2009-2011 Foresters and 2008-2011 Imprezas).

2011 Forester camera harness "i146" (plugs into HU):
Text Technology Font Electronic device Gadget
White Blue Light Footwear Shoe
Electronics


Based on Subaru's Forester wiring diagram, we have:
Code:
Pin  Color         Function
===  ============  ========
1   Blue/Yellow   Camera Video signal (+)
2   NC
3   White/Blue    Camera power (+6V DC)
4   NC

5   Grey          Camera ground (shield)
6   Blue/Orange   Camera detect (connect to chassis ground)
7   NC
8   NC
(with pin 5 connected to a braided shield that surrounds the pin 1, 3, and 6 leads).

2012 non-nav models with the camera use the same 8-pin plug and wire colors. On both 2011 and 2012, all of the wire colors change near the camera.

Pin-out for the OEM Kenwood Navi camera socket (as discovered by muzza here):

Code:
Pin  Function
===  ========
1   Video +
2  
3   [Camera power V+]
4  

5   Video ground (shield)
6   Camera detect
7   [Camera power ground]
8
(there is no factory harness, hence no wire colors).

Grounding the 'Camera detect' pin tells the HU that a camera is connected.

A European Legacy owner sent me the service manual for an older (~2008) EUDM Legacy/Outback OEM Kenwood Navi. The pin-out for the camera socket matches what muzza found. Additionally, it shows that the HU provides +6V to power the camera on pin 3 (and does that only when the HU sees the reverse gear signal). It also shows pin 7 is a ground for the camera power (not used by the OEM camera).

I recently helped a 2011 STI owner switch from the OEM Kenwood Navi to an aftermarket HU. I measured +6V on pin 3 on the HU's camera socket. A 2012 owner opened up his CM631UD (which is similar to the CP635U1). The PC board has labels on the 8-pin camera socket that match the above pin-out table (including +6V for power to the camera).

Awhile back, JoeySTi measured +6V on pin 3 when the car was in reverse. That would seem to validate the above pin-out. However, he found odd readings on the other pins (for example, +25V on pin 6). It's possible he was using an auto-ranging meter and didn't realize it had changed to a lower scale.

scarecrow93 measured +3V on pin 6, but saw no voltage on pin 3. [I thought he used an analog meter, but that may have been someone else]

silencery measured +2.85V on pin 6. That matches the voltage I've seen on the detect line for the aux input, so that seems to confirm pin 6 is a camera detect input. He didn't see a voltage on pin 3.

scarecrow93 also saw than pin 5 is tied to the HU's chassis ground. That confirms that the video signal is standard composite. (other information someone sent me had suggested the video signal might be balanced / differential, but I doubt that's the case).


(I'll update this post as we learn more)
 
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#2 · (Edited)
I wonder if the CP635U1 HU does not provide the camera power unless it A) sees the enable lead grounded, and B) the car is in reverse (which means ignition is 'on').

Once we confirm the voltage, I think we'll have enough information to safely test connecting the factory camera to an aftermarket HU. However, it would be nice if someone with an oscilloscope could check the waveform and amplitude on pins 1 and 5, to confirm the video signal too.

If you post measurements, say if all the model numbers on your HU are the same (or if any are different than what I wrote in post #1, post yours).

It would be nice to see some clear, close-up pictures of the other end of the camera harness (in the tailgate), and the camera's plug.
 
#6 · (Edited)
I wonder if the CP635U1 HU does not provide the camera power unless it A) sees the enable lead grounded, and B) the car is in reverse (which means ignition is 'on')
I'd be willing to bet you're right. Makes sense. If pin 5 is the shield and we theorize pin 6 is the camera enable, I'd also bet that the remainder of the wiring is similar to what muzza posted.

Definitely still need to verify the voltage on pin 3.

Might have to make a trip to the electronics store and see what I can rig up to ground pin 6 to the "extra" ground at the back of the HU.

BTW...I used a digital multimeter. :icon_wink:
 
#5 ·
2011 Foresters without a factory installed HU containing a video display have a completely different wiring harness [?]
As far as the factory camera harness, yes it's likely the different models have different camera harnesses.

I haven't seen wiring diagrams for models that don't have the CP635U1 HU. But I suspect that if there is a pre-installed camera harness, it runs from the tailgate to near the mirror. It's entirely possible that some models don't have a camera harness at all.

It's also possible that models with the CP635U1 have that same harness (from tailgate to mirror), plus an extension from the mirror down to the HU.

The HU's 20-pin power/speaker harness is the same in all 2011 models (except the base models that don't have the phone/Bluetooth SWCs do not have the 3rd SWC wire at pin #13).

In models with the CP635U1, the mic/aux harness has additional leads for reverse gear and parking brake. I'll add that pin-out later.
 
#7 · (Edited)
and the definitive answer is....

I spent some cash and downloaded the HU's service manual from smpcshop.com and have the definitive pinout for the HU's cam connector (J901).

According to the service manual, here it is:

Pin 1: CV(+)
Pin 2: Cam SW
Pin 3: Cam +5v (other places in the manual refer to this as +6v)
Pin 4: NC
Pin 5: CV(-)
Pin 6: Cam Det
Pin 7: GND
Pin 8: NC

I have the illustration but don't have the required posts to put it up, but these pinouts are letter for letter out of the manual.

Hope this helps ya, SVXdc.
 
#8 ·
I will be receiving my rear camera kit tomorrow and trying to install it this weekend. On the installation sheet, it indicates the possible need for a trim removal tool, however it is not included as part of the camera kit. For those of you who have installed the rear backup camera, was it necessary to have ? Seems like most of the panels can be removed with sockets or a screwdriver set.

Thanks.
 
#9 ·
switching the video display

I have a question: Does anybody know if I can switch the camera video display from the Tomtom nav HU to the auto-dimming compass? I did not realize when I test drove that getting the tomtom HU changed the camera display. On me for not fully testing it out, I guess, but just never occurred to me. Hate having it on the dash instead of in the mirror, and also absolutely hate the Tomtom HU and want to trade it out, but don't want to lose the camera. Any ideas?

jj
 
#12 ·
Your HU uses a regular RCA plug to connect the rear view camera signal. I don't think any of the OEM units use RCA plugs, so my guess is that you will at least need a different connector.

Also, aftermarket rear view cameras get power from the backup lights. The the video screen on the HU is also triggered from the same power source. This too might be different on the OEM unit, so it's no simple matter to do what you are proposing.
 
#13 ·
I've done a little more research (and updated post #1). I've pretty much confirmed:

  • The OEM camera and HU use a standard composite video signal (pin 1 = signal, pin 5 = ground/shield). This will be the same type of signal that an aftermarket HU wants to see and that most aftermarket cameras provide.
  • The OEM HU provides +6V DC (on pin 3) to power the OEM camera. To connect the camera to an aftermarket HU, you'll need to add a circuit that provides this power.

The last piece that I haven't determined yet is how much current the OEM camera requires on the power pin. Is there anyone with the factory camera who's willing to test this?

If the current draw is low enough, there is an extremely small 6V voltage regulator we can use (the size of a small transistor, about 4mm diameter).

Once we know that, it will be fairly easy to design a circuit that takes +12V from the reverse light signal and drops that to +6V to power the camera.

I already have the 8-pin sockets needed to connect to the factory 8-pin camera harness plug, and can have yellow RCA plugs in a fairly short time. I'm deliberating whether I want to put together a complete solution (with the power converter), or make it a DIY kit with just the 8-pin socket and RCA plug.
 
#14 ·
Thanks for this Write Up DC, I posted on NASIOC, so you can ignore that post. It looks like my 2012 Impreza Sport Limited has the same radio as the 2011 Forester, so I'll be looking to put in a rear view camera, Thanks for all the valuable info!!!

Thank You!

Bryan.
 
#15 ·
Hey SVXdc? The OEM camera for Impreza too?

Just curious? Since the Forester and the Impreza share the same radio HU are the cameras the same? Can I use the OEM camera on my 2012 Impreza? Does anyone have the part numbers for the kit, also are there any wires in my tailgate since this was a dealer option? Weird thing that Subaru used the same radio and camera? but it would be cost effective to do this for Subaru.
 
#16 ·
Camera

Hi all,

Wanted to see if there is an update to this. I have a 2012 STI with NAV and doing the stereo and want to do a back up cam. If I'm reading these post correctly, it looks like I need to get an RCA between the two pins (I forget which they are 5 and 6 maybe) and get power from my backup lights? I'd sure love to get this nailed down. Has anyone done this with success?

Thanks!
 
#17 ·
I'm kinda interested in this too. I'd like to replace the OEM NAV unit with a Kennwood DNX6190HD. But I'd like to reuse the OEM back up camera PLUS the OEM combo radio/SAT antenna. I've looked up the OEM antenna harness and if you have both radio and SAT radio is splits into two at the back of the HU.
 
#23 ·
I'm also wondering if the OEM camera can be used with an aftermarket HU.
My earlier posts here provide nearly all of the information needed.

I can make a harness that will connect to the factory 8-pin camera harness (that is currently plugged into your OEM HU). I can make my adapter with an RCA plug (to connect to an aftermarket HU's camera input) plus plain wires to send +6V to the OEM camera.

You would need to build a circuit to convert +12V to +6V to power the camera.

In this thread, "owad" said he powered his OEM camera with +12V and it worked. But I don't suggest doing that without finding out whether the camera has circuitry to allow that (otherwise the camera could die prematurely). I have no idea how you would determine that (unless someone were to open up the camera and see that it actually contains the same "guts" as some aftermarket camera).
 
#31 ·
Here's a spec of what I'm planning on building:



Ordered the parts and hopefully will put one together this weekend and test it. If all goes well I'd be willing to make a few more and sell them to anyone who is interested. You would just need this and the wiring harnesses that SVXdc sells to connect your OEM camera to an aftermarket HU.

Note that my design would feed power to the camera whenever the car is started (or key is turned to ACC) if you connected the +12V ACC wire from the circuit to the ACC wire on your HU harness. This would allow for using your backup camera by selecting it manually on your HU (if it has that option). Otherwise you can connect the +12V ACC wire to the reverse sensor wire and the camera will only be fed power when the car is put in reverse.
 
#32 ·
The relay really isn't needed. The camera's current draw is so low that there's no reason not to power the voltage converter directly from +12V Accessory (or even from the reverse gear signal, if you only want the camera to work when the car is in reverse). The OEM HU powers the camera's pin 3 lead only when the car is in reverse (and that lead is only powered when the ignition is on).

The 78L06 is in a TO-92 package (the size of a small transistor):

Transistor Circuit component Technology Passive circuit component Electronic device

Here's the datasheet for TI's parts: View attachment TI uA78Lxx datasheet.pdf (700 KB)

Since the max current it can supply is 100mA, I'd recommend only using that type when powering from the reverse gear signal. But since that is its max current (and it has built-in thermal overload and short-circuit protection), you wouldn't need the fuse.

Whichever type of regulator you use, choose a part with an appropriate operating temperature range. Parts that are rated for a min of 0° C (32° F = freezing) could stop working on those cold winter mornings in many parts of the country.

The datasheet suggests a 0.33 uF capacitor on the input side, and 0.1 uF on the output side.

I would probably add a resistor in series on the input side, to knock the 12V down closer to around 8V, so the regulator doesn't have to dissipate quite so much heat (which may avert problems with the "L" part, due to it running at the max rated current).
 
#33 · (Edited)
Adjusted my design a bit based on comments:



Now using a L7806ABV, operating temp -40°C ~ 125°C, current output up to 1.5 A; with a heat sink attached as well. Yes this is overkill, but would prefer to over-engineer anything that is going to be in my car somewhere I can't easily get it out again. Also removed the relay and switched to a 1A fuse. This version would still give you the option of having your camera powered whenever ACC is supplying power, or you can connect it to the reverse gear signal wire.

I have this tested and working, will be installing one in my Foz when I do my stereo install this weekend. I can make more, so if you would like to buy one off of me please send me a PM.
 
#36 ·
You guys are seriously over engineering this, tap into the reverse lights, call it a day.

The draw is so negligible there is no need for a dedicated circuit
Yup we are. :bananapowerslide:

There's no harm in being thorough. And in my case, connecting to the reverse sensor lead is not an option since I want to be able to switch to the rear camera feed whenever I want; I specifically picked my new HU (Kenwood 6990HD) because it has a button to do this. Will be handy to have this option when I can't see out the rear window.
 
#39 ·
Works perfect!

Hey all,

I finished my install over the weekend and the regulator I built worked perfectly! Will post more pics when I have a chance.

:woohoo:



BTW thank you SVXdc for the camera/aux/audio wiring harnesses; took awhile to get everything soldered together with the Kenwood HU harness, but once that was done the install in my car took no time at all.
 
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