Installation of Speed Lock Override and Turn Signal Hazard Rear Camera Activation on 2014 Prius

I installed cproaudio's TSHRCA+SLO1 today which I purchased from the Priuschat shop.

TSHRCA = Turn Signal Hazard Rear Camera Activation
SLO = Speed Lock Overide

The system is installed and working as designed. I am posting photos here of my installation. It took a total of 5 hours including time to search for info on the internet several times during the install when I had doubts/questions and time to drive to Home Depot to get some additional connectors.

Here is the material I received:

The paper included references to two threads on Priuschat for info as well as a request to send private messages to cproaudio if I had any questions. The unit was very well put together. He included 3 pairs of connectors - you'll see later I needed 6 pairs.

I also purchased the bypass which you can see above the 4 pink male connectors. It is only installed if you want to bypass cproaudio's electronics to essentially reroute the wires back to how they were before the modification for debugging or other reasons.

I downloaded these for reference:


You see on the diagram above that 6 pairs of connectors would be needed to connect the wires behind the radio. The 4 blue T taps are used for the 2 turn signals and for the power connection (12v and ground). 4 Male connectors are also provided to slip into the T taps.


The above wiring chart was a link in one of cproaudio's thread to a spreadsheet on google drive with wiring for various models of cars. The three I've marked in yellow are the only three that are modified in this installation. This one is for 2012 - 2014 Prius - mine is a 2014.

I used these tools:
The black tool was used for crimping the wire connectors.
The red plastic tools were from an auto parts store and are "trim removal" tools.
The blue tool was used to strip the insulation from the wire ends.
The socket is used to remove the 4 bolts holding the radio.
The screwdriver is to remove one screw on the panel to the left of the steering wheel where the switches go.



I printed my reference sheets:



And started to open the dash to remove the radio. First I removed the panel below the dash that has the 12v outlet and my seat heater buttons.







This area is where the main board will go and it will connect to power on the 12v accessory outlet. You can see a red wire where I had already tapped here to install an extra 12v outlet for my dash cam. This panel was probably the most difficult of all the panels to remove. I ended up pushing it to one side to make more of a gap on the other side to be able to pry up a corner.

Next I started to remove the trim around the radio.

You should start with the round piece around the shift knob.






I did not disconnect the shift knob bezel and laid it to the side.

There is a connector for the clock set buttons that you disconnect.
Then remove the panel with the start button - but do not disconnect the start button.



Each of these pieces are removed fairly easily by pulling on them to release plastic tabs behind them.

Then you need to remove the kick panels for the driver's side and passenger side.
First remove the plastic threashold piece:

Unscrew by hand a plastic nut on the kick panel:

This is the driver's side kick panel from the back:

Remove the phillips head screw just below the hood release:


Prepare to install the switches. Remove the switch panel by pulling on it.

Choose one of the switch blanks to remove

Disconnect the switches from the harness and insert them into the hole.


Remove the radio by unscrewing the 4 10mm bolts - pull straight out. Use a cloth to protect the rest of the dash.





These are the two wire connector harnesses where you will cut wires and connect the wires from cproaudio's device.
They are on the top. The 28 pin connector and the 16 pin connector. You don't need to take out all the connectors. There are three connectors that are just interconnected to the back of the radio. Romoving the other harnesses from the radio so you can completely remove it will allow you access to fish wires and work with the wires.



Cut the wires per the diagram and install connectors. Install a male on one and female on the other end so you could connect them back up if you ever want to disconnect and remove the device. You will need to open up some of the wire jacket around the wires to get access to them.


Put the device into the space behind the 12v outlet below and fish the group of 6 wires up to the radio. Install the appropriate connectors male or female to each wire per the wiring diagram.


Connect them per the wiring diagram.


On the wire bundle that includes the switches and the yellow and green wires for the turn signal connection - you should pull the green wire out of the bundle - I ended up routing it to the passenger side kick plate to connect it to the right turn signal. I found some documentation online as to which wires were the turn signal wires - I couldn't identify a left turn signal wire on the drivers side with my multimeter (not sure I know how to check really).

Fish the wires for the switches and the yellow wire from the space behind the 12v outlet - under the steering wheel and to the driver's kick plate.
I had to remove the small panel next to the gas pedal in order to fish the harness.


Fish the green wire from the space behind the 12v outlet to the passenger side and connect it there.


Now time to connect to power. You tap the red wire to the black wire of the 12v outlet. You tap the black wire of cproaudio's device to the white/black stripe wire (this is the ground). I don't have a good photo of this.


Connect the switches to the harness and install the switches. In my cases the switches were very tight and would not go in all the way but not too bad. I may have to work on that later. The top switch is for the camera. The bottom for the speed lock override.



Use zip ties as necessary on wires, reinstall the radio and reassemble all the panels. You're done!

I tested the system before fully reinstalling all the panels. It worked as advertized. Some thoughts:

1. Problems could come from not making good wiring connections. One I did had to be redone as it came apart as I was installing the radio.
2. Reaching your hand down in the space behind the radio and in the space behind the 12v outlet can be tight. I had a couple of scrapes on my hand from it...maybe I should have worn gloves. Just a little blood in this project.
3. I put a couple of scratches on the panel holding the 12v outlet - that one is tough to remove. The others were quite easy.
4. Some of the connectors on the radio were a pain to get off for me...eventually got them.
5. After testing, the rear camera is quite effective at seeing cars in your blind spot. However, it is super wide angle and hard to judge distances well. I think I'll get used to that. The rear camera goes on and off quite quickly as the turn signals go on and off - smooth. You can turn the camera on manually with the switch. The switches allow you to disable both the camera feature and the speed override feature if you want.

I hope this helps others who try to install this product.

I used information from these sources as well:

DIY JDM style side mirrors combo lights (Signal+Parking+Courtesy lights) | PriusChat

Anyone interested in how to bypass the factory navigation speed lock? | PriusChat

Turn Signal Hazard Rear Camera Activation mod | PriusChat