CAN-Bus wiring question

[Indicava]

Can anyone point me as to where the COMFORT CAN-Bus wiring might be somewhat accessible on the A3?

Thanks!

 

[Steaman]

 

[rcnacura]

What do you plan on doing? I've been trying to crack the canbus, but very unsuccessfully. Built Arduino but still can't get steering wheel controls.

Would also like to get sport mode settings and or magride settings too.

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[DrMal]

Be careful doing this. Admittedly I left the automotive industry about five years ago, but there were specs coming out from VAG, Volvo, Ford and others around them to prevent CAN-bus hacking. While it's one thing to connect an un-configured OEM device onto a CAN network (which will just show-up as unconfigured), on certain CAN networks it's possible that a completely unrecognised node will initiate anti-tamper features.

If you're going to connect something custom built, keep it passive and simply reading off the bus.

 

[Indicava]

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Wow thanks for this. I really appreciate it.

Looking at the diagram, a lot of the connections in the rear just aren't there in my car (no lane assist, no towing recognition, no all-wheel drive), so I guess my best option is somewhere in the front.

Any suggestions on which of the control modules is most accessible without taking apart too much trim/wiring?

I do have a limitation with this project in that I can't devote more than a few hours a week to it as this point (a little more every other weekend). The car I'm experimenting on/trying to hack is my daily driver so I can't rip stuff apart or disconnect wiring til I figure this out.

Thanks!
-E.

 

[Indicava]

What do you plan on doing? I've been trying to crack the canbus, but very unsuccessfully. Built Arduino but still can't get steering wheel controls.

Would also like to get sport mode settings and or magride settings too.

Sent from my Pixel 2 XL using Tapatalk

My "final" goal is unlocking/locking the car from my smartphone. But honestly as this point, I'm still in a very early trial and error and experimentation phase. I'm a total noob at car hacking, however I do have years of experience with software, hardware and networking . I'm a tech geek so I'm enjoying the process at least as much as the (hopeful) final result.

 

[Indicava]

Be careful doing this. Admittedly I left the automotive industry about five years ago, but there were specs coming out from VAG, Volvo, Ford and others around them to prevent CAN-bus hacking. While it's one thing to connect an un-configured OEM device onto a CAN network (which will just show-up as unconfigured), on certain CAN networks it's possible that a completely unrecognised node will initiate anti-tamper features.

If you're going to connect something custom built, keep it passive and simply reading off the bus.

Very interesting input, I'm really just playing around at this point and I'm trying to be as careful as possible.

These anti-tampering measures do sound interesting though. Can anyone else with some CAN-bus hacking experience on the 8V shed some light or personal experience on this?

 

[rcnacura]

My "final" goal is unlocking/locking the car from my smartphone. But honestly as this point, I'm still in a very early trial and error and experimentation phase. I'm a total noob at car hacking, however I do have years of experience with software, hardware and networking . I'm a tech geek so I'm enjoying the process at least as much as the (hopeful) final result.

Might be easier just to set something up using the key fob. I'd be little more learly with doing this as I'd want better safety/hacking measures like some type of authentication/token.

Might be also easier just to retrofit the kessy system if you don't have it already.

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[rcnacura]

Very interesting input, I'm really just playing around at this point and I'm trying to be as careful as possible.

These anti-tampering measures do sound interesting though. Can anyone else with some CAN-bus hacking experience on the 8V shed some light or personal experience on this?

Realistically, you should only be reading canbus/LINBus signals and apply to a third party system to control something else. I'd stay away from inputting as the car is very sensitive and will throw error codes along with weird behavior of the DIS. Luckily there are built-in safety protocols that shouldn't allow erroneous signals to control much.

I've only gotten as far as listening to the volume control buttons, but not always successfully to control my Android system.

Skip to about 3 minutes in...


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[Indicava]

Realistically, you should only be reading canbus/LINBus signals and apply to a third party system to control something else. I'd stay away from inputting as the car is very sensitive and will throw error codes along with weird behavior of the DIS. Luckily there are built-in safety protocols that shouldn't allow erroneous signals to control much.

I've only gotten as far as listening to the volume control buttons, but not always successfully to control my Android system.

Skip to about 3 minutes in...


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Hey I actually saw your video before! Very cool stuff and thanks for the tips.

We have the same car (at least the one you had in the video 2015/A3)!

Do tell, where did you tap into the CAN bus wires?

 

[4K]

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That's great! Where did you manage to get that diagram from? Elsawin?

 

[rcnacura]

Skip to about 5:25 there are two wires in the rear, yellow I believe, that is the entertainment canbus. I believe it's on 100kbs



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[Steaman]

From SSP 610- Audi A3 13 Onboard Power Supply and Networking

 

[Steaman]

 

[rcnacura]

View attachment 147386

That explains why I couldn't get it to work, looks like VW has moved everything to 500kbs.

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[Norbit13]

Hi there
Could someone help me figure out this diagram (above), its for an THOR Electronic Exhaust, i need to find out where the CAN, CANL and ACC wires are in my Audi A3 8v 2013
Thank you

 

[Rcord]

All CAN bus connections can be found in the Gateway module, installed in the dasboard, buth the easiest place (IMO) to connect wiring to CAN bus connections in the A3 is at the set of connectors installed at the left A pilar bottom area, that you can reach by removing the bottom pilar trim. But you have to know to which of the 5 CAN Buses you should connect your device. As you probably know, they have different serial communication speeds, so you need to know what's your device's baud rate in order to connect to a compatible bus.

The diagram you supplied shows "CAN" and "CANL" wires, when the right tags should be "CANH" and "CANL" (Can high and Can low). I suppose "CAN" is meant to be "CANH". CAN bus wires are a twisted pair in order to avoid electrical interference and CAN low is always an orange/brown wire and CAN high is the other wire in the pair. The wire marked as ACC in the diagram seems to refer to +VCC, connected to car's 12V supply through a fuse. There is no indication in the diagram if it's a switched or a permanently powered point, but I suppose it's switched because it doesn't seem to be a device supposed to work when ignition is off.

Another important question: did you make sure the device is compatible with the A3 8V? I'm asking this because, since it's a CAN Bus controlled device, it has to be able to decode the messagens sent by the car, and CAN bus messages may be different from a car brand or model to the other. If the device is intended to be controlled by the engine speed RPM, it's contained in the message 0xA8 in the MQB platform, but the message containing the RPM info is different even in other platforms on the VAG group.

 

[Norbit13]

All CAN bus connections can be found in the Gateway module, installed in the dasboard, buth the easiest place (IMO) to connect wiring to CAN bus connections in the A3 is at the set of connectors installed at the left A pilar bottom area, that you can reach by removing the bottom pilar trim. But you have to know to which of the 5 CAN Buses you should connect your device. As you probably know, they have different serial communication speeds, so you need to know what's your device's baud rate in order to connect to a compatible bus.

The diagram you supplied shows "CAN" and "CANL" wires, when the right tags should be "CANH" and "CANL" (Can high and Can low). I suppose "CAN" is meant to be "CANH". CAN bus wires are a twisted pair in order to avoid electrical interference and CAN low is always an orange/brown wire and CAN high is the other wire in the pair. The wire marked as ACC in the diagram seems to refer to +VCC, connected to car's 12V supply through a fuse. There is no indication in the diagram if it's a switched or a permanently powered point, but I suppose it's switched because it doesn't seem to be a device supposed to work when ignition is off.

Another important question: did you make sure the device is compatible with the A3 8V? I'm asking this because, since it's a CAN Bus controlled device, it has to be able to decode the messagens sent by the car, and CAN bus messages may be different from a car brand or model to the other. If the device is intended to be controlled by the engine speed RPM, it's contained in the message 0xA8 in the MQB platform, but the message containing the RPM info is different even in other platforms on the VAG group.

Thank you for your help, now it makes more sense than just a diagram
And yes i even called them, this device is compatible with every kind of car made from 2005
Thanks alot

 

[Rcord]

Thank you for your help, now it makes more sense than just a diagram
And yes i even called them, this device is compatible with every kind of car made from 2005
Thanks alot

That's good. Please post an update when you finish the installation. There may be more people in the forum interested in that retrofit.

 

[Norbit13]

That's good. Please post an update when you finish the installation. There may be more people in the forum interested in that retrofit.

i would but its too much work and i dont have a garage to do all of this and to lift the car up high enough to fit the speaker, my best solution is to go to The main dealer in UK and get it fitted professionally without any problems in the future, if anyone ever gets a Thor Electronic Exhaust I highly suggest to take it to the experts as the damages i would definitely do myself arent worth it haha

 

[DJMitchell]

View attachment 210591 Hi there
Could someone help me figure out this diagram (above), its for an THOR Electronic Exhaust, i need to find out where the CAN, CANL and ACC wires are in my Audi A3 8v 2013
Thank you

Hi, I have just purchased a thor exhaust kit too! fitting it to my audi a4 avant b8. Did you get it fitted by the garage and if so did they inform you which can wires they tapped in to?
cheers

 

[DJMitchell]

All CAN bus connections can be found in the Gateway module, installed in the dasboard, buth the easiest place (IMO) to connect wiring to CAN bus connections in the A3 is at the set of connectors installed at the left A pilar bottom area, that you can reach by removing the bottom pilar trim. But you have to know to which of the 5 CAN Buses you should connect your device. As you probably know, they have different serial communication speeds, so you need to know what's your device's baud rate in order to connect to a compatible bus.

The diagram you supplied shows "CAN" and "CANL" wires, when the right tags should be "CANH" and "CANL" (Can high and Can low). I suppose "CAN" is meant to be "CANH". CAN bus wires are a twisted pair in order to avoid electrical interference and CAN low is always an orange/brown wire and CAN high is the other wire in the pair. The wire marked as ACC in the diagram seems to refer to +VCC, connected to car's 12V supply through a fuse. There is no indication in the diagram if it's a switched or a permanently powered point, but I suppose it's switched because it doesn't seem to be a device supposed to work when ignition is off.

Another important question: did you make sure the device is compatible with the A3 8V? I'm asking this because, since it's a CAN Bus controlled device, it has to be able to decode the messagens sent by the car, and CAN bus messages may be different from a car brand or model to the other. If the device is intended to be controlled by the engine speed RPM, it's contained in the message 0xA8 in the MQB platform, but the message containing the RPM info is different even in other platforms on the VAG group.

Excellent explanation! Would you know where the best place to connect wiring to CAN bus on an Audi a4 avant b8? I also have bought a thor exhaust system. Cheers