Vauxhall Owners Network Forum banner
1 - 20 of 20 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter · #1 ·
Hello! I would like some information surrounding the CAN bus systems of Vauxhall’s (specifically the Corsa C’s).
I am currently doing some academic research surrounding the CAN bus and have chosen the Corsa C (2004 onwards) to focus on for now, as I own one myself. I would love to find out if any sensor data (for example, the wheel speed sensor data surrounding TCS, ABS etc) passed along the CAN bus is stored (locally, not in a drive computer / black box). Would anyone be able to help with this?

To summarise, is there any kind of local storage (preferably non-volatile) for the various sensor data communicated across CAN bus? I must add emphasis in that I’m looking for storage local to the sensors/CAN bus, not in an external recording system. Any pointers or general CAN bus information would be greatly appreciated!
 

·
Well-known member
Joined
·
15,922 Posts
It is certainly stored on the Corsa D and can be accessed retrospectively which is of particular benefit to car rental companies. An example would be over speed data for the engine.
 
  • Like
Reactions: FlynnW01

·
Registered
Joined
·
13 Posts
Discussion Starter · #4 ·
Corsa c doesn’t have sensoring data storage. Nonsense, why would makers spend valuable money on memory chips, except overspeed data and fault code freeze frame data?
What do you use for can reverse engineering?
Read this: http://pikkupossu.1g.fi/tomi/projects/i-bus/i-bus.html
Hmm, I was assuming the same, but I’d like have a more definitive answer. The only reason I could see there being memory chips (non-volatile) is that these vehicles did not rely on a central computer like they do today. Would you know how I could find out in writing what memory the CAN bus/sensors do/don’t have?
Also, I am just looking into reverse engineering. However, I am currently using Simulink’s vehicle network toolbox to simulate CAN bus data from various data sheets. I would just like to determine what data we might have access to local to the CAN bus. This would help with the direction of the project.
Thank you for the link too, I will check it out!
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #5 ·
It is certainly stored on the Corsa D and can be accessed retrospectively which is of particular benefit to car rental companies. An example would be over speed data for the engine.
Thanks for this - do you know where exactly it would be stored? Currently, I am interested to find out if any memory exists local to CAN bus / sensors.
To add context, the focus of my research surrounds data forensics in legacy type vehicles that use full CAN bus - ignoring central drive computers/black boxes. We are checking to see what data could be retrieved along the network.
 

·
Well-known member
Joined
·
15,922 Posts
The data regarding over speed events is stored in the ECU and can be accessed using a high end Professional version of OpCom.

Incidentally if you are interested in vehicle data forensics you are probably already aware that VW (and probably Audi as well as others in the group) store non volatile data recording the last 5 minutes of inputs. It is typically only saved after ignition off in certain events, typically collisions whether leading to air bag activation or not, or emergency braking that has activated the hazard lights, as just 2 examples.

That data is not easily accessed but exists.
 
  • Like
Reactions: FlynnW01

·
Registered
Joined
·
13 Posts
Discussion Starter · #7 ·
The data regarding over speed events is stored in the ECU and can be accessed using a high end Professional version of OpCom.

Incidentally if you are interested in vehicle data forensics you are probably already aware that VW (and probably Audi as well as others in the group) store non volatile data recording the last 5 minutes of inputs. It is typically only saved after ignition off in certain events, typically collisions whether leading to air bag activation or not, or emergency braking that has activated the hazard lights, as just 2 examples.

That data is not easily accessed but exists.
I see, are you referring to the Corsa D here? If so, does that run on full CAN bus? At what point would that data be recordedLast, do you know of any other events that would be stored in the ECUs?

Also, this VW data recording is interesting, do you know where would this data be stored? This might be slightly more in the direction of a central computer but I’d like to look into it more.

Please feel free to just drop relevant links to save you typing away!
 

·
Well-known member
Joined
·
15,922 Posts
Corsa D is full CANBUS.
I think the data is continually updated.
There is loads of historic data stored but I don't have a list available or a suitable car to plug into at the moment.

The VW data is definitely there on the Golf ⛳. I don't have further details I can share but this is a field I have worked in, directly linking in with VW technical department. 😀

Doubt if you just rang them up they would even acknowledge the data exists.
 
  • Like
Reactions: FlynnW01

·
Registered
Joined
·
13 Posts
Discussion Starter · #9 ·
Corsa D is full CANBUS.
I think the data is continually updated.
There is loads of historic data stored but I don't have a list available or a suitable car to plug into at the moment.

The VW data is definitely there on the Golf ⛳. I don't have further details I can share but this is a field I have worked in, directly linking in with VW technical department. 😀

Doubt if you just rang them up they would even acknowledge the data exists.
Perfect, thank you for this! I will do some more digging on it. Appreciate the insider knowledge 👍.
 

·
Registered
Tigra Twintop 1.8 AT Z18XE AF17
Joined
·
489 Posts
What you're looking for does not exist in Corsa C. No one will tell you where and what structure that memory has because that is secret data and not public available.

Who is we?
 

·
Registered
Tigra Twintop 1.8 AT Z18XE AF17
Joined
·
489 Posts
I would just like to determine what data we might have access to local to the CAN bus. This would help with the direction of the project.
To begin with, almost anything you see in your Corsa C instruments panel is canbus data sent. Except if I remember right, airbag light and 1x engine management light, which are hardwired. All the rest, canbus data.
 

·
Registered
Tigra Twintop 1.8 AT Z18XE AF17
Joined
·
489 Posts
As for reverse engineering, plenty tools are out there, from really cheap ones to really really expensive ones. When I started with this, I went down this route but had to change to a more comfortable solution.



This is how my Corsa C canbus physical layer looked like, although there is a small mistake in connectors numbering.

 

·
Registered
Joined
·
13 Posts
Discussion Starter · #13 ·
As for reverse engineering, plenty tools are out there, from really cheap ones to really really expensive ones. When I started with this, I went down this route but had to change to a more comfortable solution.



This is how my Corsa C canbus physical layer looked like, although there is a small mistake in connectors numbering.

Hello,
Apologies for not getting back to you on this. This is very helpful, thank you. I was wondering if you’d know hypothetically (ignoring external factors like privacy issues), are we able to place some cache on the CAN bus to store our own copy of CAN bus data information? Perhaps using one of the low speed ports?
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #14 ·
Hello,
Apologies for not getting back to you on this. This is very helpful, thank you. I was wondering if you’d know hypothetically (ignoring external factors like privacy issues), are we able to place some cache on the CAN bus to store our own copy of CAN bus data information? Perhaps using one of the low speed ports?
I am thinking along the lines of (again, hypothetically), modifying the firmware of the CAN bus to make sure all communications that go over a bus are downsampled and sent back over the port we designate as a black box port? Is this feasible?
 

·
Well-known member
Joined
·
15,922 Posts
Isn't that what black boxes fitted by insurance companies and rental companies already do? They don't generally provide real time telematics and instead cache data which is then transmitted via embedded eSim cards to the companies who manage those boxes.

Short answer is yes it can and is already being done.
 
  • Like
Reactions: FlynnW01

·
Registered
Joined
·
13 Posts
Discussion Starter · #16 ·
I am thinking along the lines of (again, hypothetically), modifying the firmware of the CAN bus to make sure all communications that go over a bus are downsampled and sent back over the port we designate as a black box port? Is this feasible?
Isn't that what black boxes fitted by insurance companies and rental companies already do? They don't generally provide real time telematics and instead cache data which is then transmitted via embedded eSim cards to the companies who manage those boxes.

Short answer is yes it can and is already being done.
I see, thank you for that. Veering off track a little but do you know if any forensics (post-collision) could be done / is being done, using sensor data alone? Is it possible to have some kind of probe as I mentioned and retrieve enough stateful information to recreate events? Logically, I would assume the type of data insurance companies access, that this wouldn’t be too difficult? I made another post on stateful information if you’d like to help with that? It is along these lines too, about what kind of data could be pulled from CAN bus.
 

·
Well-known member
Joined
·
15,922 Posts
Yes it is possible.
 

·
Registered
Joined
·
13 Posts
Discussion Starter · #18 ·
Yes it is possible.
Hmm, do you think possible theoretically? Or has this already been done? I’m not sure if it is common to prioritise this kind of strategy for collusion forensics, as things like witness reports and physical signs like tyre marks etc are more telling at surface level.
 

·
Well-known member
Joined
·
15,922 Posts
Possible and being done.
 
1 - 20 of 20 Posts
Top