I recently got a 2004 Vitz with some cool factory upgrade. (Most of the world has the Vitz under the “Echo” brand, the Vitz means its imported from Japan) Coming from Japan, it came with a factory new stereo system which only worked in Japanese, did not play MP3’s and committed Seppuku when unplugged from the battery.
(While this is a post about replacing the stereo, a quick note – Toyota New Zealand are absolute bastards, and I won’t do business with them. They would not even tell me the part number or frequency of the remote the car uses – because they correctly knew I would pick up an aftermarket one for a fraction of the price. I didn’t even ask them about the disk needed for the firmware for the radio – required to restore it to working (in Japanese) after the battery is unplugged – which I believe sells for over US$100 and can’t be easily found online. I have resolved to ensure Toyota New Zealand never see a dime of my money – thus far they have lost out on a service and break fix for my other Toyota which my wife wanted to get done through a Toyota dealer).
Anyway, information on getting the factory reverse camera working with this vehicle is very hard to come by. Using some educated guesses and a lot of Googling I managed to get my (new, cheap-and-cheerful Chinese import Radio/display) working. Hopefully this information is useful to others.
The first thing to note is the camera is powered by the radio with a 6 volt supply. While I don’t know the current draw, the wires are very thin, so I’d imagine its not much current. Of-course, most stereos don’t supply 6 volts. This is easily rectified with a LM7806 voltage regulator IC and a couple of (possibly not needed) 100nf or similar caps. I used 200nf ceramic ones. The 7806 (rated to 1 amp dissipation) voltage regulator cost about $US3 from Jaycar with a small heat-sink.
The original connector to the stereo has 4 pins – 2 of them are ground (black and white, and connected together with a wire as per the image), red being 6 volts, and yellow being the signal.
Bastardizing an RCA lead, I soldered the yellow wire to the centre pin and grounded the shielding wire against the chassis. I fed this in to the reverse camera input of the stereo.
There is a 5 pin cable on the standard stereo with 3 wires, the green/white wire measuring 12 volts when the car is reversing. I tapped this line both to power the camera through the LM7806 (ie indirectly to red wire) and the reverse signal input in the stereo – which means the output is automatically displayed when reversing.
The wiring for the LM7806 is quite trivial. Looking at it head on, the centre pin goes to ground/chassis, the left pin goes to the green wire (or another source of voltage > 8 volts DC) and the right pin is the regulated 6 volt DC which goes to the red pin of the reverse camera. For good measure I threw a 200nf ceramic cap between the input voltage and ground, and another one between output voltage and ground. (Some stuff on the Internet says this is not required, I did it because that’s what I was taught to do in another life when playing with its close cousin the LM7805 and TTL logic circuits, and I believe its best practice. At least it can’t hurt – if you don’t somehow damage the 7805 while soldering them on !) Unfortunately I lost the picture I took of this.
Although it took me a long time to do, it worked first try.