Recording telemetry from CAN bus / funky stuff with VCDS?

[passact]

Not sure if this is best here or in performance.

What I'd like to do is tap into the CAN bus for the engine / drivetrain and record more advanced data than is available over OBDII - things like steering position and torque, wheel speeds, yaw rate, etc.

From what I've read so far (and happy to be correccted), VCDS works on TP 2.0 and is more of a request / response system, but that's why it can run through the gateway.

If I want detailed, live data, can I request that, while driving, through the OBD port, or will I need to dive into detailed CAN stuff by tapping directly into the drivetrain bus on the other side of the gateway?

This page: VW Transport Protocol 2.0 (TP 2.0) for CAN bus | jazdw.net refers to both "logical IDs" and CAN IDs. Does VCDS / TP 2.0 run primarily off the logical IDs, and can I monitor the VCDS traffic to extract the actual CAN IDs for the various components?

I've also seen people playing with the "convenience" bus to intercept steering wheel buttons, or do things like roll windows down - it that feasible through VCDS / TP 2.0 / from the OBD side of the gateway?

Can you command the car to do stuff via VCDS? Can I set the cruise control speed, roll windows up and down, etc?

[DV52]

^^^^ pascat: I don't know what type of car you have, but my understanding is that if the CAN gateway can measure it, it will be available for monitoring/recording through the VCDS cable. I assume that you have a genuine Ross Tech cable, or a VCP cable (don't get a clone, they are complete rubbish and they thieve legitimate IP).

Have you tried looking at the extensive list in Advanced Measuring Values for the control module of interest?

Can you command the car to do stuff via VCDS? If the module will allow you to change a parameter, then it's generally possible to make the change with a VCDS cable. The change can be either a coding string modification, or a change to an adaptation channel. Some control modules need a security code before changes can be made.
Can I set the cruise control speed, roll windows up and down, etc? Not sure about the cruise control speed (if you have the physical equipment installed, wouldn't you set this via the button on the steering wheel?), but depending on the car (and the control module) its generally possible to turn-on/off comfort eindoe opening/closing

Don

[passact]

Sorry, should have said - 2009 3C Passat diesel.

It sounds like VCDS is more "configuration" than "command" - I don't have VCDS (yet) so don't know exactly what it can do. One of the things I'm trying to work out is what VCDS can do before I drop $400 for a cable and setup.

Is VCDS only intended to be used in the shop, or can it be used for on-road testing (assuming you've got a second person running the laptop)?

[DV52]

Sorry, should have said - 2009 3C Passat diesel.

It sounds like VCDS is more "configuration" than "command" - I don't have VCDS (yet) so don't know exactly what it can do. One of the things I'm trying to work out is what VCDS can do before I drop $400 for a cable and setup.

Is VCDS only intended to be used in the shop, or can it be used for on-road testing (assuming you've got a second person running the laptop)?

Configuration vs command? Not sure that I understand the difference. VCDS is ostensibly a diagnostic tool, but that said, it's a fairly versatile bit-of-kit.

Yes, lots of stuff can be done when the car is stationary (is this what you mean by used in the "shop"?), but it can be used with the car in motion (for recording and plotting measured values). Unless you get the HEX NET, you need to be careful of the cable (if your ODBII connector is near the accelerator) and you are correct, Ross Tech warn that a second person should be using the laptop when the car is in motion

Two suggestions before you buy the cable: visit the Ross Tech web site and have a look at the on-line manual and try to find a forum member that lives close and who has a cable that he/she can demonstrate!
Don

[jamesatfish]

Bit of a revival but I only just noticed this thread...

The CAN Gateway in our VWs provides a device on the OBD2 port with controlled access to specific ECU modules on a one-at-a-time basis.

When using VCDS, you make a request through the CAN Gateway to access a specific module - let's say the control module for the front driver's door. It doesn't matter to VCDS what bus that module is on - the CAN Gateway forwards the CAN packets on the appropriate bus to the correct controller.

Whilst connected to that controller you can view data from the controller (door open/closed, door locked/unlocked, window position etc) and in some cases issue commands to the controller (roll up windows).

What you can't do is connect to multiple controllers at the same time - the CAN Gateway will only connect you through to a single controller at a time, so if you want to see the state of the front passenger's door you need to disconnect from the driver's door module first.

Some modules (like the engine module) have visibility over data from across the car, so connecting to the engine module for example can be a good way to track and log the majority of 'telemetry' data in the one place.

If you want more detailed data then the solution is to bypass the CAN Gateway and connect to the CAN Buses directly. VCDS isn't the tool for this - you need more specific hardware, a knowledge of the proprietary and closed-source VW CAN dictionary and the tools to capture and manipulate CAN packets directly on the bus.

The advantage is that you're able to capture raw data from every single controller all at once, and you can issue commands without needing to access individual controllers.

I see you're in Canberra - if you're interested in this stuff come past our office in Fyshwick for our BBQ on Saturday 7th May (DashSketch Launch & VAG Community BBQ - Saturday 7th May) and we can explain the process and show you some of the tools, as this is what we do for a living.