6th Gen Steering wheel in 5th Gen?

[Rainbow1616]

Pretty sure I just popped them out with a trim tool. I still have my original steering wheel in the shed I can look and take pics if you need them.

[slonison]

Originally Posted by Rainbow1616

Pretty sure I just popped them out with a trim tool. I still have my original steering wheel in the shed I can look and take pics if you need them.

Hey Rainbow,
I was going over your wiring diagrams and I noticed that the 2012 section has everything I need. But the 2016 appears to not have the cruise control switches. I see the decision on the audio control (very interesting that audio control is the audio+directional pad+volume buttons+fav buttons)

But for the left switch I might be missing it but I'm only seeing the section related to the heated wheel (which I did need).

Do you have the 2016
1. Cruise control wiring diagram?
2. Paddle shifter wiring diagram?

I have the resistance ladders all listed out for the 2012 and was able to begin documenting everything. And I get consistent readings with my multimeter.

[slonison]

Ok guys, the entire steering wheel has been torn down to the circuit boards (except the paddle shifters. I shouldn't have any reason to tear them down. They are either going to be flat continuity or give some small resistance from their pins which should be able to be measure with them intact (unless they have diodes which means I will have to tear them down.

My initial observations before I get into the details:

The schematics are dumbs down substantially compared to what I've worked on before.
They are separated into two/three general circuits.
Heating Control
Cruise Control
Audio/Info Control

Note: the following are assumptions until I dive in...

Heating is the easiest. It's basically on and off.

Cruise control
You need to understand how it works before we talk about what can go wrong. If you've had a 5gen, then you know what you activate cruise control. You first have to flip a toggle switch on the wheel. This is because at resting / off, there is no continuity. When you flip that switch, it gives a steady resting resistance. Which gets lowered when you press set or resume. This is important because when I did my mustang, I thought you could ignore the resting resistance (Bluetooth, audio, and info control allowed you to, so why not speed control???) well, the mustang is always monitoring that resting resistance, otherwise it will activate cruise control, then immediately kill it, if it doesn't detect the resistance. I suspect the Camaro operates the same. Ya know, since it's a matter of actually controlling a moving car. This is a problem, because the 6gen (is 2016+ called 6th gen?) has a momentary button. At least that's how it looks. This means it doesn't stay activated. I know of a work around but this could prove to be a small headache up front. Luckily, we have empty pins in the clockspring if needed (I hope they are on the ribbons inside. Adding that to my to do list to check). To be honest, this steering wheel seems like it has a lot of room inside (comparatively speaking) and so we might be able to solve it INSIDE the wheel.

Audio/Info
The two sets of lower switches and the upper right switches all come together as one unit. The problem here is that instead of a standard resistance ladder in the PCB, there is actually a micro controller on the board. I suspect that this interprets the resistance ladder/income signals and spits out an action for the BCM. It's not a big problem, but will require us to get creative with how we solve this.

I'm thinking two possible solutions.

Option 1:
We pull the microcontroller from the board and Frankenstein a resistance ladder onto the board. I've done this before. It's not impossible but takes a lot of preplanning.

Option 2:
We see if we can listen to the signals the micro controller is outputting to the bus channel and then, because I'm familiar with it, use an esp32 to fake the output under the dashboard. The esp32 listens to the signal, and based on what it hears, it sends the correct signal to the regular dash connector.

I'm not sold on either yet to be honest.

More to come. It's past midnight and I need to hit the sack. Sneak preview in the attachments.

[slonison]

So I made a lot of progress over the last few days.

And some of my fears have been confirmed.

Cruise control.
Unlike the cruise control from the 5g, the 6g has an always on resting position. And I don't really see anyway of getting around this. There isn't a toggle on the wheel anywhere that can be repurposed without looking silly. The brightside is that the way the 6g is wired, it's basically always on. If you are ok with cruise control being "always-on" then this is going to be some easy resistor swaps. If not, which I'm not, not really, it's back to the drawing board to see if there is a way to incorporate a toggle switch (even a small tactile one, somewhere on the steering wheel.

Audio. This is actually where I've spent most of my time and it's a nightmare. Basically, all of the audio functions are handled by a small micro controller and sent out via a bus channel. This isn't impossible to work around but as I said, it's going to require some work. That work being, I think that the integrated chip is going to need to be tossed in the bin. Unfortunately, that intetrated chip actually also controls the backlighting of the LEDs. Again, not impossible but a set back.

Ironically, I learned that all the back lighting LED power goes to the right audio switch and is then sent out to the rest of the switches from there.

Additionally, the left paddle switch send a it's signal to the right paddle switch before exiting the clockspring. This will be probably the easiest to update.

I'm contemplating explaining all of this in a video series like I did with the mustang because explaining it here doesn't do it justice.

The summary of it all is. Possible? yes. Fun? Maybe. Easy? No. Quitting? Absolutely not!

[slonison]

Alright guys. time for a quick update.

There're a couple things I want to chat about to or at least put down on paper regarding where I've gone with this.

2012: Generally speaking, the way the system works is:
Cruise Control: Car applies voltage, car listens on ground for voltage drop.
Audio: Car applies voltage, car listens on ground for voltage drop.

2016:
Cruise Control: Car applies voltage, car listens on ground for voltage drop.
Audio: Microchip listens on different legs depending on the switch and then sends a digital signal back to the Body Control Module to react accordingly on the LIN BUS.

Cruise Control is actually going to be easy; I've already identified the resistors to swap and with which values.

Paddle Shifters actually have the same values being output (despite the wiring diagrams saying otherwise, weird).

That leaves the micro chip. I was originally going to decouple the LED control from the microchip and remove the micro chip entirely, but if I do that, the tertiary favorite and volume buttons will die. There rally isn't a solid way of do this because both buttons go STRAIGHT to the ground plain from their corresponding pcb. I could probably cut the line and recycle and empty resistor location on the pcb, but I really don't like permanently damaging the pcbs.

I could forgo the tertiary buttons entirely, but hell that would suck big time. I already planned to repurpose the D-pad to be volume +/- and fav forward back but having dead buttons would just be too lame. And my wife deserves better.

So the new plan is actually going to be to decode the digital signals sent back on the LIN BUS line with a logic analyzer and then built a digital to analog signal converter (most likely using something cheap like an ESP32 which can listen for those signals and then send the appropriate signal to the car.

Honestly, despite this set back, I'm really excite to dive in. The last part of the logic analyzer comes in today. I'm going to try to give it my all tomorrow... Here's a few pictures to hold you all over.

[camguynj]

[slonison]

Bench test.

Activation light turns on, heat turns on.

I actually may take something that I learned from this and apply it to my mustang.

We're moving along.

[camguynj]

[slonison]

So I've run into a hiccup.

While trying for several days to reverse engineer the Lin bus signal on this switch, I can't see to figure out how to get the mlx80104 to wake up and respond. The wiring diagram says the switch communicates with the instrument cluster. So I ordered an instrument cluster on eBay. Not sure that I'm going to be able to get the IPC to send a signal to the steering wheel, but I'm gonna give it my best shot. We'll see what happens.

[slonison]

Progress to be had and progress to be lost.

With some help of the smart people on the Arduino discord. I was finally able to get some signals back from the IC. Unfortunately less than 40 seconds after getting my first signal. I accidentally sent 12V back into my laptop via the USB port. Well that fried the entire USB power rail in the laptop. So I have to repair that before I can get back to deconstructing the digital Lin bus signal.

I ordered a new USB power switch to swap onto the board but until that comes, I'm at a bit of a stand still. I may work on the cruise control in the meantime however. I was able to get an entire second set of switches for $40 on eBay so I have a spare set that I can tinker with. I'll keep you guys updated as I get around to working through some of these things