GM Lan Single Wire CAN Bus Sniffing

[brentsten]

I might be off track here, but I found this in another thread:
Just flicked through the service manual, looking at connectors, harnesses, etc.

The video input for Rear Aux, which is connected to the roof DVD player normally, is signal to pin 14, ground to pin 5.
The video input for the Reversing Camera (drum roll please) is signal to pin 15, ground to pin 6.

Knowing that, why not just grab a stock .bin file from tis2web and flash the radio to think it has a roof DVD player? Connect the video on pin 14 and 5 instead of 15 and 6 and theoretically it should work, right? If you see any logic in this or think its worth a shot, I'll grab a bin file from a roof DVD car, switch the pins and give it a go.

[abodah]

I have made some progress, I'll post the results soon.
I also have a GMW3110 as pdf, anyone who needs it, just PM me.

Thanks

[ZerOne]

Hi Brensten,

The DVD roof player uses the same Composite AUX video input (That everyone is playing around with).
The problem with the roof mounted DVD player, if your head unit still has the factory VIM enabled, then the display goes blank when the vehicle is in motion. (There is nothing fancy about the roof mounted DVD player, it is connected to the SW Can, however it looks like the Can information for it is used only for the Roof mounted button illumination, and possibly screen dimming).

I dont even think the head unit can control the roof mounted DVD player.
(To be honest, Ive had my car for two years now, and I have never stuck a DVD in the thing to test it out and make sure it works)...
Most useless feature on my car to date !

The headunit software / firmware for both Roof mounted DVD and non roof mounted DVD players is also the same.
(I.E. non roof mounted Head units support roof mounted DVD players).
I am currently running a HSV Clubsport Headunit and fascia (which didn't come with roof mounted DVD player) in my calais, and it behaves exactly the same as my original unit.

[brentsten]

ZerOne: Thanks for the clarification.. and now that I think about it, that makes sense. The main display would still turn off regardless of where the source video is coming from.

Jezzab: You're right about Tech2/SPS not allowing .bin modification; I was thinking of DPS.
DPS will allow you to push a modified .bin file in. I have a trial version of it, but programming is disabled. It looks like the older versions needed a hardware key (presumably a USB stick) to allow full access and the new version is a software key that has to be approved individually through GM after which they send you a .bin file to unlock the application.

I'd really like to be able to put this CarDAQ to use and Vehicle Spy looks like the perfect application, but it looks like they only support the NeoVI or ValueCAN hardware and its big bucks anyway. Are there any other GUI applications that support the CarDAQ Plus? It seems silly for how much these things cost and there isn't any software available from even Drewtech short of giving you .dlls and having you write your own.

[abodah]

Attached

[abodah]

My news
I bought a windows 7 Tablet (Atom) with built in 3G for phone calls and web surfing.
I made a VB6 app that controls the HVAC, and can be controlled by Steering Wheel Buttons.
Added a USB GPS Reciever, so I can activate the GPS Navigation Function.
Also Added Wireless USB cam for reversing. It opens when the gear's in "R" which is also a message from the GMLan bus.
Now I need to remove the IQ system, and install this one instead ( I'll need an audio amplifier).

I also bought a copy of Basic4Android, programmed my first android app that controls the car keyless entry system.
The ELM327 didn't help me with that because I couldn't manage to get a wake up signal from it, my solution was:
I took a signal from a fuse located in the fuses box in the footwell, my car is LHD so the fuses box is near the OBD2 socket.
That signal is high when the engine is running, and low when not.

When I send commands to the ELM, the LEDs glow, I used this, and the engine running signal to pass a VBat to the GMLan when I need a wake up signal. It worked

[abodah]

Also bought a rear sensors, wired the signal into a microcontroller, then to "Serial to USB".
Now I can read the distance through the tablet.I will make a chime command to convert this into chimes.

All ideas are welcome

[ghodge]

Hey Abodah,

Good work. I can't weight to see pics of the mounting of your tablet. What message do you see when the transmission is put into "reverse". I remember looking for it but I couldn't find it any of my logging sessions.

Thanks,

George

[saabdriver]

Hi,

I'm a new member here and all I can say is wow... you guys have made some progress with GM canbus. I have a Saab 9-3 and I'm just beginning to get started with this...

Two questions...

Is the I-bus in the 2003 Saab 9-3 similiar to GMlan?

Where is the GMLan bible that everybody keeps talking about?

Any help is much appreciated. Sorry if this post is in the wrong forum section, pls move it if necessary.

[abodah]

saabdriver, thats the gmlan bible:
https://docs.google.com/spreadsheet/ccc ... zMXc#gid=1

on the other hand, I got the initial pics for my project after installing. thats one pic for now. P.S. sorry for my mobile phone camera, its a 19XX nokia .

Image0019.jpg