So, when I bought my RX300 a couple of weeks ago, one of the things not working on it was the reversing camera. Something I now find pretty essential!
Last weekend the plan was to see if my cheap £5 Chinese reversing camera could either produce a signal the sat nav unit could use, or even better replace the Lexus original.
Well, I can report I've got the camera working and displaying pictures on the sat nav unit. It wasn't all smooth sailing, as the sat nav unit refused to display the signal from the reversing camera on it's own. There seems to be some feedback from the Lexus camera that lets the sat nav unit know it's connected. Without it the sat nav shows a blank screen.
However, I'm not one to be beaten, so by keeping the rear PCB of the Lexus camera connected and just tapping the Chinese camera into the video line, I've now got a working reversing camera. The Chinese camera even clips into the original Lexus camera housing without modification. All I had to do was remove the guts of the old camera to make space. The Chinese camera requires 12v and the sat nav unit supplies 6v so I tapped into the 12v supply for the passenger side reversing light. That way power is only supplied when reversing.
The wiring ended up like this. The yellow video wire from the old camera is cut and the new camera connected between the black and the yellow wires to the sat nav. The black, red and white wires stay connected in order to keep the sat nav displaying the video signal.
As you can see the power leads off to the reversing light and the rear PCB of the original camera is still in place to provide the feedback signal. The PCB ended up wrapped in tape and tucked into the rear hatch. Once I'd proved the camera could work, I fitted it into the original housing, then the housing was screwed back onto the mounting bracket by the two screws and then bolted back in place in the hatch.
It ended up looking ok:
On the left is the old camera unit. It simply plugs onto the circuit board that stays connected, so I just unplugged it.
Finally here's the result on the screen. It has the guide lines, but you can buy cameras without these and also with or without image mirroring. You just need to specify when ordering. This is one I already had so I wasn't fussy. The other thing to specify is it must be the American NTSC video standard to work with the sat nav, not the European PAL system. I haven't tried the fancy stuff like park assist yet as it hasn't been necessary. I'm just happy to be able to have working video. If the guide lines affect parking assist I might have to bite the bullet and fork out for a genuine camera, but we'll see.
I hope this helps anyone with camera problems in future.