Adding backup camera to 2012 non-nav Prius 2 with touch screen

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Warning: Doing any of the following modifications could cause damage to your Prius's electrical system and/or void your manufacture's warranty. Also some of these procedures require soldering of electrical components. If you are uncomfortable with doing any of these procedures, then it is highly recommended that the backup camera be installed by an automotive accessory shop or some other facility that has experience in installing rear view cameras. Performing the backup camera installation via the following instructions is at your own risk.

WARNING WARNING WARNING WARNING WARNING WARNING

So if you are still reading this, you feel you have the skills needed to do a successful install of a Prius rear view camera. We shall see

On Jul 4, 2012, man2ing started the "BACK UP CAMERA FOR 2012 PRIUS two TOUCH SCREEN - NON NAV". Over a year later with 360+ appends and over 49,000 views, the thread contains many different ways that Priuschat members have added backup cameras to their Prius. The problem is the install procedures are scattered amount the 18 pages of appends. The hope is this thread will contain these install procedures/guides at the beginning in a more easy to find format.

All the info in this thread comes from the hard work of many PriusChat members, among them: IMKenNY, ray6088, wildiin, man2ing, Hank101, DumLong, kumatae, dimetech, PaJa, priusbee, PriusTime, Dan4500, LanLam, Willco Electronics, DogPrius, nelsc, Wes_33073, zebelkhan, and jonathaneugene for all their help in making this guide. If I forgot someone, I'm sorry, but I do thank you for your effort.

This info will be divided into 4 parts: cameras, voltage regulators, running the wires and making the connections.

 

Cameras
There are quite a few cameras on EBAY that are designed for the Prius. They have a D shaped base that fits the cutout already in the back hatch of the Prius.


Some vendors that people have used are cardvd2010 and chenwenjiaoeb09. The cameras are usually under $20 and are shipped from Hong Kong. The only problem is that the vendors change suppliers so the camera someone orders today may not be the same one they send you a year from now.
One thing to note is that bump in the cable coming from the camera. That bump is usually a 12V to 3.3V regulator. It turns out a lot of "12 volt" cameras are really 3.3 volt cameras. Make sure if you do buy a camera it has that bump. That improves the chances that it is a 3.3 volt camera making it much easier to install.

 

Voltage Regulators or Relays

Assuming you bought a 3.3 volt camera, there is just one problem. The voltage the Prius supplies to the camera is 6.5 volts. So, there are three things you can do:
1) Modify the original voltage regulator to take 6.5 volts and convert it into 3.3 volts.
2) Build your own 6.5 volt to 3.3 volt regulator
3) Use the 6.5 volts from the Prius to control a 6 volt relay that will switch 12 volts to the camera.

1) Modify the original voltage regulator:
Willco Electronics did the following:
I modified my 12v camera by cutting rubber molding on the inline regulator circuit. The circuit consist of surface mounted resistors and capacitors on one side and an AS1117, 3 terminal regulator. There are two 680 ohm resistors on the input side of the regulator that are connected in parallel. I removed them and added 4, 10 ohm surface mounted resistors. I piggy backed 2 resistors on top of the other 2 with a total os 2.5 ohms. The camera now will operate down to 5.5 volts and maintains 3.3 volts to the camera.


Before photo


After photo

jonathaneugene did the following:
Using my very fundamental understanding of Ohm’s law, I reasoned that if my
circuit decreased voltage by ½, then if I wanted the amperage to remain similar
to before the mod, I should decrease the resistance by half. So I took out one of
the two resistors and replaced it with solder. Also, since I cut off the insulating
rubber, I re-soldered a few of the connections so they wouldn’t short on each
other when I taped it up with electrical tape. A picture of his modified voltage regulator (and his guide) can be found in the "making the connections" part of this thread.

2) Build your own voltage regulator:
For us folks who can hardly see the SMT components in the original voltage regulator, this is the parts to build your own. The part numbers are from DigiKey
497-1492-5-ND Voltage regulator : -40 to 125C
445-8618-ND TDK .1 uf .197 spacing
445-8552-ND TDK 10 uf .197 spacing
The schematics for this circuit are on page 6 and 8 in the voltage regulator spec attached below. The complete voltage regulator looks like this:



3) Use the 6 volts from the Prius to control a 6 volt relay that will switch 12 volts to the camera
A solid state relay is pretty expensive to buy, so Dan4500 designed his own:
Based on what I know now, I have come up with a circuit that does the work but with parts that are easier to get and are cheaper. Should be about $1.00 plus the circuit board if you decide to use it. Just 2 transistors and 5 resistors. The resistors are all the same value (1.8k, 1/4 watt) as they usually sell them 5 or 10 in a bag. The transistors are the 2n2222 (NPN) and MPS8550 (PNP). Very common, from Frys, Ebay, or probably Radio Shack. I've used 2 resistors in parallel to get the proper drive from the 2N222 to the MPS 8550. It's wired into the 12 volt camera the same way. Dan4500 just added that you can swap a 2n2907 for the MPS8550. There have been some posts saying the 8550 is hard to find.
Below is Dan4500's schematic for his solid state relay:

 

Running the Wires
This section deal with running 3 (or 4) wires from the back hatch where the camera is to a connector behind the drivers kickpanel:




Since this involves removing the plastic interior panels, it is suggested to get some trim removal tools like Harbor Freight's 5 Piece Auto Trim and Molding Tool Set ( item# 67021 ). It runs around $8.

It is possible wire the camera to a connector under the headliner. But MANY people have said it is a pain to remove the head liner to get at that connector, so they recommend connecting at the drivers kickpanel. But a few Priuschat members have gone the headliner route.

Willco Electronics said:
I just installed my modified 6 volt camera and it works. Because it was so close, I wired it to the connector on the headliner. I removed the three plugs that hold the headliner and partially unsnapped the left rear side panel. It gave enough room to reach in and snip the white, red and orange wires. I connected the three camera wires using wire nuts. It made a small crease but it wasn't noticeable after I snapped it back in place. I used trim tools that purchased from Harbor Freight. The white, red, orange and black wires were together in a separate bundle. After cutting the wires, I was able to pull the bundle towards the back and I didn't have to reach as far to make the connections. I wanted to remove the overhead light but I couldn't see where or how to remove the lens. Working in the headliner I forgot mention that Harbor Freight has a selection of "long reach" tools that are affordable. Long reach, long nose pliers and wire cutters cost about $15.
...Bill also went the headliner route. He said :
I connected under the headliner. It wasn't too bad. Yes the headliner creases a bit, but no evidence after it's all back together. It is a bit of a pain working in there, but after removing all of the hatch trim panels, lowering the back of the headliner wasn't too bad. I removed the rear dome light and part of the left rear trim by that little rear window. I was going to tap into the connector wires, but ending cutting them and splicing on to my cable to save my sanity.
I also modified the in-line 3.3V voltage regulator that came with the camera to work on the 6V supply from the HU. I removed the surface mount resistors and used some conventional 1/4W parts I had laying around. I know many folks are scared away by the fine soldering skills needed, just take your time. Expect to re-solder all of the wiring connections as they will all break as you manipulate that little circuit board.
See appends #41 and #50 of this thread for more headliner installations.

Here’s the connector under the headliner where the camera connections are located.
You can see the white, red, black and orange wires.



When you segregate the wires from the other bundle cut them as close to the connector as you can. Grab the four wires and pull the bundle towards the rear of the car. I used small wire nuts.

Before you start, make sure you disconnect the 12V battery in the car.

When you are removing all these panels, the last thing you want to do is hit a live wire.
Attached is some guides that shows how to remove the panels. Also below is a video that show the panels being removed.

A lot of the guides show them removing a lot of panels that they don't need to. Remove only what you need to get the wire from the back hatch to the driver's kick panel area. Also you may only need to partially remove a panel just enough to slip the camera wire behind it.
The outside panel on the rear hatch (the one that the camera will snaps into) is held on by 4 nuts on the inside that can be reached after all the rear hatch trim has been removed. Make sure those 4 nuts are removed before you start prying on the outside panel.

Dan 4500 said: I found that a little silicone lube works wonders to get the cable through the rubber tunnel thingy between the roof and the hatch. This the stuff used by swimming pool service guys to keep the gaskets on the equipment moveable but yet watertight. Since the tunnel thingy is silicone rubber, it's very compatible. And don't forget to use masking tape or cord to pull the rubber back up over the plastic trim piece on the hatch (see below two pictures).






Below are 2 guides that show how to take off the interior trim.

 

Making the connections

So the camera is attached, the wires have been run to from camera to the drivers kickpanel, so the last thing to do is to connect up both ends.

MAKE SURE THE 12V BATTERY IS DISCONNECTED

There are 4 wires coming from the car/HU that are used by the camera:
White wire - This is the +6.5 volts for the camera power
Orange wire - This is the return for the camera power
Red wire - This is the Video+ signal for the camera
Black wire - This is the Video ground signal for the camera. This black wire is not used in any of the installations.

The HU does some testing to see if a camera is present when the car is turned on. Dan4500 did the following analysis:
The trick is that early on in this quest, from reading all the postings, I had erroneously thought that the orange wire was directly connected to ground (0 volts) and that the HU detected current on the 6.5 volt white wire. After some testing a few days ago, I discovered that the orange wire was not connected directly to ground, but appeared to have a function in addition to receiving the camera current. That's why I call it "return" rather than "ground". The current from the 6.5 volt white wire meanwhile, is not detected by the HU. (HU merely supplies 6.5 volts.) It looks like on Start/Power-up the HU turns on the 6.5 volts for 2-3 seconds to allow detection of the camera current on the orange wire and then goes off. Then if the camera was detected, putting in reverse turns the 6.5 volts on, activating the camera to send video to the HU.

Most camera have 3 wires coming out of them
Red wire - This is for the camera +3.3 volts power
Black wire - This is for the camera ground (and the video ground signal)
Yellow wire - This is for the Video+ signal



If you are using a modified original voltage regulator you will notice that there are two sets of wires coming out of it. In one of those is a yellow and black pair and the other is a red and black pair. The two black wires are tied together on the voltage regulator circuit board and are the ground wires. The red again is the camera power and the yellow is the camera video signal.

At the end of this section is a guide from jonathaneugene that shows detailed pictures of the wires (car red, car orange and car white) in the kickpanel and how to connect into them.

The wires are connected as follows for the modified original voltage regulator.
Note - if you are using this method, the wires (red, black and yellow) between the camera and the voltage regulator should not have been cut :

car red wire to voltage regulator yellow wire
car orange wire to voltage regulator black wire (since both black wires are tied together, you only need to connect one and you can tape off the other one)
car white wire to voltage regulator red wire.

The wires are connected as follows for the home made voltage regulator.
Note - in this case, the wires between the original voltage regulator and the camera should be cut and the original voltage regulator is removed:
car red wire to camera yellow wire
car orange wire to camera black wire AND voltage regulator black wire.
car white wire to voltage regulator red wire
voltage regulator green wire to camera red wire

The wires are connected as follows for the 6 volt relays.
Note - in this case, this is way over my head and I'm going to apend Dan4500's schematic for the solid state relay. Also note that the wiper motor wire (light blue) supplies the 12 volts needed to power the camera. Dan4500 added: By the way, if you use my circuit make sure to disconnect the 12 volt battery before connecting to the 12volt blue wire at the wiper. It's live at all times. The other points are off when the ready is off. Not the blue wire though.
Also make sure that the car orange wire is used as the ground for this circuit:



Jonathaneugene's guide (attached) has some close up pictures of the kickpanel with the orange, white and red wires and how to connect into them. He chose to wrap the wires around the pins (so it could be undone - clever , but you can solder, splice or do what ever it takes to make a solid electrical connection.

Dropbox - 2013 prius backup camera guide.pdf

 

All Done
After making sure all the electrical connections are taped up and everything is secure, the HU should detect the camera when the car is turned on and display a picture from it when the car is put into reverse.
Don't forget to reconnect the 12V battery

The original thread : "BACK UP CAMERA FOR 2012 PRIUS two TOUCH SCREEN - NON NAV" has much more info (and pictures) than what I have copied here. If you need some more info, you may want to check that thread and see if it is there.

Again I would like to thank all the members of PriusChat that figured all this out and created some great guides that were used in the making of this document.

 

This is my first shot at making the condensed guide. If something is incorrect in it, please let me know so I can update it. If everything looks good, well make a sticky of it so it won't be buried. Thanks.

 

Dan4500,
Believe it or not I haven't done mine yet. I 'm waiting for someone to make a guide so I didn't have to wade through all those appends to see how to do it Actually I waiting for my 36K warranty to expire, but the wait is killing me !!!. I'll be going the home made regulator route. I'm trying to decide if I'm up to the challenge of taping the wire in the headliner vs the kickpanel. I just updated the "relay page" with your transistor change.
When I left last night, there were 51 views. Now it is up to 121. Got a way to go to hit 51K of the other thread.

 

ny_rob,
I see it can do 3 amps. I wonder if that is too much current for the "orange wire" can carry.

 

ny_rob,
That was my concern. How much draw the converter used. I know with my camera and my home made regulator, it was drawing about 120 milli-amps.
zbelkhan,
Don't temp me. Every time someone added an append saying their camera is up and running it reminded me of Christmas where everyone is getting presents and there is none for me I've got everything ready to go (camera, homemade regulator, tools etc). I don't know how much longer I can stand to wait !!

 

Dan4500,
In about 4 month, I'll have 36K on the Prius (the camera will be my Christmas present). Wonder if I can get Santa to install it for me.
Since I haven't heard anyone say anything was wrong with this summary, I'll assume all is good and get it sticked.
Thanks again to all of you for your contributions to this guide.