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GT350 Reverse Camera

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j3st3r

Brian S.
604
376
Tennessee
Not sure if this has been discussed at all, but does anyone know if there is a way to enable the reverse camera, on cars equipped with it, all the time? Would like to enable this while at the track if possible, maybe put it on its own switch
 

j3st3r

Brian S.
604
376
Tennessee
Going to look for wiring diagram, I am guessing the camera gets power when reverse is activated, so might be able to put a switch in with a diode or relay
 
Here is a quick explanation and a very simple circuit for what you are looking for.

First of all, the camera gets power when you press the start button from the battery junction block – upper left of the circuit. The Body Control Module (BCM) controls when the camera should output video to the Front Control Display. In the GT350, the transmission and all of its electrical components are in the PCM, not much there like the reverse lamp switch, trans temp, output shaft speed, vehicle speed sensor. In the GT it’s different. It has its own module for the transmission probably to provide support for the optional automatic. So I suspect that the PCM sends a CAN Bus message to the BCM to tell it to switch the camera video on. I also assume that the Front Control Display simply switches the display to video if video is detected on the input.

So first, you want to measure the voltage on connector C2280E pin 37 of the BCM. It will be the violet wire with a white stripe. The BCM is located in the passenger side foot well behind the kick panel. Not sure if its 12v or 5v. Since I assume you want your switch in the passenger compartment, the next step is to measure how many amps are going down the wire to the camera from the BCM. With the car off, strip back some of the insulation wrap of the huge connector C2280E – it has 52 pins. Go back a couple of inches. Now cut the violet/white wire and hook up a VOM. Connect one lead to each side of the cut wire and set the VOM to read amps so that you can measure the amperage on the wire. This will be a very small number. Push the start button without starting the car and take the trans in a out of reverse and record the amperage on the line

Now calculate the resistance that the BCM sees from the camera circuit. Assuming 12v and 0.025 amp current flow, 12/0.025 = 480 ohms. For this circuit I would use a tiny pc board mount relay. Find a 12v relay (coil is driven by 12v), relay contact rating is irrelevant at this voltage and amperage. Get the datasheet and find out the resistance of the coil. As an example, let’s take 390 ohm as the coil resistance. So we need a total resistance of 480 ohm from above. The relay coil provides 390 ohm which leaves over 90 ohms (480-390). So we need another resistor inline (in series) with the coil. You can use a 100 ohm resistor since they are very common and cheap.

So if you look at the circuit below, the violet/white wire coming from connector C2280E pin 37 of the BCM now goes to the relay coil and then onto a resistor and then to ground. So the BCM, when turning the camera on, sees 0.025 amps flowing on pin 37 and thinks there is a camera there and everything is working as expected..

Here is the circuit:

upload_2018-9-11_18-43-25.png

The whole point of the left part of the circuit is to trick the BCM into believing that the camera control line is hooked up when actually it isn’t at all. I seriously suspect that if one doesn’t “simulate” the camera properly, the correct current value is flowing, you will get DTC codes. The BCM is quiet “smart” with detecting errors like broken wires or when the current flow goes out of range. Obviously, you will need to find a 12 relay with a coil resistance less then the total resistance that you calculated was needed. That is why I recommend a tiny pc board type relay. A computer output only uses very small amperage to drive the output. Point is get a close as possible with the total resistance.

So on the other side of the circuit we have a 2 position rotary switch. Position 1 is OEM operation of the camera – meaning that the video is displayed only when you are in reverse. Follow the trace and you see that it feeds 12v to the camera out the other side of the cut violet/white wire to the camera but only when the relay is activated by the BCM. OEM operation.

Position 2 is camera always on. The violet/white wire going to the camera is fed 12v regardless of what the BCM is doing on pin 37.

So fairly simple, a 12v relay, a resistor, and a two position rotary switch.

5v vs 12v. Everything up above hold true either way. Just replace 12 with 5 above even the calculation of total resistance. Obviously you would need a 5v relay.

Down side is that there will be a click of the relay whenever the BCM switches over to the camera.
 
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Another thing that will help is the pin outs for the BCM connector C2280E.
I apologize for the gar-belled explanation above. I cleaned it up :)

upload_2018-9-13_8-4-2.png

BTW, at some point (probably during the winter) I'll do something like this to control the exhaust valve. Same basic idea. OEM, always open, always closed. I loath the idea of having to get under the car to switch harnesses or plug in a resistor. Another remote is not what I need at $200+. BTW, now you understand what they are doing with the plug in resistor :) They are tricking the PCM (in this case) into believing that the exhaust valve solenoid is hooked up when in fact it isn't.

You could mount the circuit above in a small plastic box and put it in the sun glass tray. That is where I would plan to put the exhaust valve switch.
 
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@blk2017 let us know if you figure out the exhaust valve.
 
@VoodooBoss

The circuit to get it to do what I want is the easy part! I don’t want to cut up or splice into my harness though. I hate hacked up harnesses…

In the case above with the reverse camera, you don’t have any options but to cut into the harness because there are no inline connectors for the line that controls the video. First thing I looked at. It’s one continuous piece of wire from the BCM back to the connector on the camera.

I have been looking at how to do an exhaust valve switch in such a way that you don’t have to modify any harness. There are a number of inline connectors that the wire travels through from the PCM back to the exhaust valve solenoids. I think I found one that will minimize the work involved. I will start another thread on that with a write up. Anyone should be able to make it.

Even though I want to do this as a winter project, I have 6-8 weeks of lead time on getting parts here from the US so I have already been working on it.
 
1,246
1,243
In the V6L
If I were doing it, I'd spend some quality time figuring out the part numbers of the housings and pins for two four-pin solenoid connectors C345 and C346. I'd make a pair of socket to plug pass-through assemblies and do all the harness work within that set of wires. Those connectors have power, ground and control signal connections, so you don't need to connect to any other wiring in the car to do a "manual on - manual off - automatic" selection with some switches, relays and ballast resistors. Personally, I'd prefer to have a "Manual - Auto" switch and an "Open - Closed" switch instead of a three position rotary, but hey, that's just me.

I just did a bunch of this kind of engineering on my 2016 Track Pack - I have the Sync3 upgrade in mine and I decided to finish the job of making the climate control work. When you install the Sync3 upgrade, the manual heater controls are replaced by automatic ones, but the car doesn't come equipped with all the sensors and actuators that the factory automatic setup has. Mine has all that now. Climate control does a much better job of holding temperature now!
 
The Ford Service Part Number for C345 and C346 is BU2Z-14S411-TB

You are completely right when you said that everything you need is back there by the solenoids.

I have this wonderful modification that the German TÜV shoved down my throat which is a muffler where the stock X-Pipe was. They flipped out that car has an exhaust valve. They said no more the 95db period, valve open or closed. So I got a 1500 Euro muffler added. Its like 95db with the valve open and quieter then a 4 cylinder VW Golf with the valve closed! I hate this thing and took it out right after the car passed TÜV. Problem is that when you hit the gas and the PCM rips open the exhaust valve, I have major potential issues on the street. If I get pulled over and they determine that I modified what the TÜV did, I would have major trouble. So I need a solution that doesn’t hack up my wiring.

Wonderful state imposed mod, isn’t it? On top of that, it's already starting to rust!

upload_2018-9-14_8-39-55.png

I see a couple of problems with what you are suggesting though
- There is a lot of heat back there right at the exhaust solenoids. The Grimm Speed solution works. Their resistor keeps the PCM happy. Great for exhaust systems that don’t use an exhaust valve. I believe they embedded the resistor in epoxy. But you also need two, one for each side. Also defeats what we all want and that is “automatic mode”. It does solve a few issues though, keeps the PCM happy, keeps the exhaust valve closed (because its disconnected), and doesn't hack up the wiring.
- You need two “circuits” back at connectors C345 and C346, one for each side. If you move back one or two set of connectors, you would only need one circuit and would be further back (towards the front of the car) away from the heat
- Not sure what 2 switches would do. Gives you 4 options. I can understand manual – open and closed but auto – open and closed I do not understand unless auto is simply auto. In that case you still have 3 possibilities just like the 3 position rotary switch. User interface is preference though I guess. Either way, you have 4 switch lines (wires) to contend with.
- With two separate switching units, one at each solenoid, you will overly complicate the switch wiring
- There is no way around what you are calling a ballast resistor. Only way to keep the computer output port happy and not throw DTC codes. Switches are needed like the two you would prefer. I agree that the relay is not the optimal component choice but in the case of the reverse camera above its easy to understand, simple to wire up, and cheap. You need someway to “simulate” auto mode so you need to tap into what the PCM (or BCM) is doing on the pin so you can duplicate it. Optimally you would want to use an opto-isolator but harder to spec out and most if not all are now SMD – surface mount which is a bear to mount / solder for most people. There might still be some opto-isolators out there in different packages available.

Probably makes more sense to start another thread on the exhaust valve. Input from others is always good :)
 
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1,246
1,243
In the V6L
I agree that we should move the exhaust discussion to a new thread - perhaps a mod could pick up the existing posts and move them? Just a thought...

Specific to the camera then, C4357 is the camera connector and it has all the signals you need to implement the schematic that blk2017 posted above. The camera is controlled by the signal on pin 2 of C4357, which is the same wire that blk2017 selected in his post, except he called out the other end - pin 37 on C2280E at the BCM.

So, to implement his approach to controlling the camera, you start by inspecting the camera connector on the car - if you're lucky there'll be a part number on it. You then search that part number on the Mouser (or other site - Google is your friend) and that will lead you to the housings for the male pins and female sockets. You buy a mating pair of housings and some pins and sockets - the whole works might set you back $20 or so - and then build a pass-through harness that connects all the pins (except pin 2) straight through from pin to pin in the male housing to the female housing. For the two pin 2's, those pins get lengths of wire that become a pigtail that you're going to run to the new control setup that's remote somewhere in the car. To provide all of the signals you need, you also tap into the power and ground wires. When you're finished making the pass-through, you have a plug and socket pair a few inches apart that plugs in between C4357 and the camera with four long-ish wires coming out of it - the BCM side of pin 2, the camera side of pin 2, +12v and ground. You can make this four-wire pigtail as long as you want, so if you're inclined to put the switch, the relay and the ballast resistor from blk2017's schematic in the dashboard, just find a factory bundle that's going that way and follow it with the new bundle.
 
Dido!

Good explanation! There are 10 ways to skin to a cat long as you understand what the BCM is doing and what it wants to avoid the dreaded DTC codes. I would prefer to avoid the back – people above reported heat issues and any potential water issues from up under the bumper. This is why I would put everything up near the dash. But good explanation!

It might also be cool to add another camera - front looking which would also be easy to do...

BTW, I will start a new thread on the exhaust valve.
 
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