MpndngDoon

Hi all!

I am installing one of those Tesla-style Android head units in my 2007 RX 350. So far so good. I got everything working (including the OE backup camera). I was replacing an old GEN5 Multi-Function Display head unit (Toyota 86110-48320).

I did need to MacGyver a few things with my wiring harness (moving pins) and in so doing, forgot where two pins were supposed to go. I kind of know, but am not 100% sure. It's two wires coming from the head unit; each carries 2.5v... which could be for LEDs or lighting. Might be important... might not. Nothing changes with the voltage when I'm in ACC or have the car completely powered. They stay constant at 2.5v (unless I turn off the car completely).

My question: Does anyone know what these two pins (#9 and #10) are for on the old GEN5 unit?

THANKS!

DennisMik

The wires on pins 9 and 10 are canbus. Pin 9 (orange wire) is Tx+ and pin 10 (light blue) is Tx-.

See page 3 of the attached file, right side of page, approx 2 inches down.

MpndngDoon

Whoa! Where have you been all my life? I've been scouring the internet for hours and hours to find a diagram like that. THANK YOU!

OK, so 9 and 10 are canbus... the question is: what are the used for? I could just plug them back in. What do you think would happen if I got them reversed?

DennisMik

The canbus is used for a lot of things. Almost every (if not all) control modules use the canbus to relay information/commands to some other part or module. For example, when you press the unlock button on the keyfob, the receiver module will send the instruction to the door lock mechanism to unlock via the canbus. If you keep holding the unlock button, the receiver module will send the command to the master window switch to open all the windows.

If you connect wires for the canbus backwards, you will probably end up with a lot of things that don't work. I have never done that or seen it done, so I am guessing. The canbus is a type of data communications and those interfaces are designed to be short circuit proof. Whether the Toyota designers adhered to those standards is unknown to me, so I would not want to risk a backwards connection.

MpndngDoon

The manufacturer has not been super responsive about this or what these wires are even for.

After looking at a bunch of wiring diagrams, it seems that there is a standard for solid versus striped wires:

Solid = positive
striped = negative

I’m going to try matching the polarity of the wires to the polarity of the pins as per the diagram you sent and see what happens.

I’ll report back with my results.

DennisMik

I wouldn't bet my life on this at all. I can find a lot of striped wires that have +12 volts on them. I think that many times the striped wire indicates that the signal/function of that wire has gone through a switch or another device and is no longer direct from the source. But not always. Sometimes it appears that a striped wire gets used just because a lot of different wires are needed.

There are only 13 different colors used for the wires. The colors and their schematic codes are: B = Black, L = Blue, R = Red, BR = Brown, LG = Light Green, V = Violet, G = Green, 0 = Orange, W = White, GR = Gray, P = Pink, Y = Yellow, SB = Sky Blue.

When you have connectors with 20 or 30 or 40 wires in them, stripes get used to avoid having duplicate or triplicate colors. But even this statement is not true 100% of the time. You will find duplicate wire colors in the same connector.

If there really is a pattern as to when a striped wire gets used, I definitely don't have a clue.

MpndngDoon

Unbelievably, I got a pretty good answer from the manufacturer/seller last night:


Whether a standard or not is unclear, but they also used the green/black striped wire for negative (-) and the solid green for positive (+). Seems like this might be for the AC controls (which are still working without these hooked up &#129488.

Margate330

I haven't studied the wire colors as much as I should but have noticed they use white wire with black stripe a lot for ground wire.

+1 Dennismilk above
As far as the striped vs non-striped I wouldn't count on assuming one always being voltage and the other always ground or vise versa because just when you think you got it figured out something goes up in smoke. I work on Japanese and European electronics.

MpndngDoon

Yup. Point taken. Now that the manufacturer has confirmed the wiring, I will try it out and see if anything has changed.

mmulvihill

how did you get the factory back up cam to work