Decoding the CAN BUS

[KensBlueGenX]

Thanks for the information.

It shouldn't be that complicated. I design systems like this for a living. I know for sure its going to be a learning curve.

Keep us posted!

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[Sirmais]

I'm ready to pay someone if he can release me from this error in dash, as I don't have this START/STOP on my car and never had! Just instrument cluster came from the car with the system.

 

[KensBlueGenX]

I'm ready to pay someone if he can release me from this error in dash, as I don't have this START/STOP on my car and never had! Just instrument cluster came from the car with the system.

First off, this would be better asked in its own thread as it is off-topic of this thread.

That being said, what are the stored body DTCs?

(Note - not all low cost ODB II scanners will read the Honda body codes data set. Be sure one is used that will.)

 

[Frapuchini]

As I mentioned before, there's a DBC file for our cars on GitHub. This reverse engineering work is mostly done and is open source. Check out this video to see what this open source project has managed to do with a 10th gen civic:

The work done here is astonishing. I knew this was possible but I didn't think someone has done it.

 

[mrburgerUS]

I've been thinking about building a CAN BUS sniffer to decode the CAN BUS.

Has anyone here been able to play with the vehicle's CAN BUS?
Any tables with CAN BUS commands or anything available?

I'm interested in potentially doing an engine swap. I don't want to completely obliterate the stock electronic systems since I'm not making a race car.

I think that what is holding the 10th gen civic platform back is the lack of understanding of all the electronic systems.

I want to use some of my spare time to develop a dummy ECU just to fool the rest of the electronic systems into a correct working state.
This could open the possibilities for future swaps.

I really tried to give the L15b7 a change but the small displacement shifts the powerband up into the higher revs when using larger turbos.
I also looked into increasing the displacement for a more pleasant powerband but it seems that even aftermarket sleeves won't cut it.

No tables, have fun!
I did some of this work, but it’s not “just plug and go!” easy. This is a canon event, either you learn to reverse engineer and build CAN Sniffers and interceptors, or don’t do this project.

An ECU with factory message integration is monumentally difficult. If you can do it, sell the idea.

 

[mrburgerUS]

"CAN BUS" is just the communications protocol used on one or more data links in most vehicles. (There are two on these cars, the B-BUS and F-BUS.) Sort of like TCP/IP is in the internet world. Reading the data traffic on these buses is the easy part. There are a lot of commercial packet sniffers out there that will do that.

Decoding those packets, that's the tricky part. With the exception of DTCs, all that data is proprietary information of the various vehicle manufacturers.

Aftermarket product manufacturers spend many 1000s of hours hacking/cracking them so their particular product will work.

Here's a good primer on the basics - https://www.csselectronics.com/pages/can-bus-sniffer-reverse-engineering

Good luck.

Actually, take that back. Comma did work with the ECU and message frames they needed for self-driving. But there are whole swaths of codes and variants of packet payloads per trim that this misses, especially on the interior side (radio, suspension, gauges, HVAC, EPS.

This got me started, and I used super-thin t pins in the backside of the radio connector with FCAN to tap the data. I’d recommend a UTP 2-wire setup with a connector on the other end of your choice.

 

[Frapuchini]

Actually, take that back. Comma did work with the ECU and message frames they needed for self-driving. But there are whole swaths of codes and variants of packet payloads per trim that this misses, especially on the interior side (radio, suspension, gauges, HVAC, EPS.

This got me started, and I used super-thin t pins in the backside of the radio connector with FCAN to tap the data. I’d recommend a UTP 2-wire setup with a connector on the other end of your choice.

I'll see what I can do. Not to brag but I have designed CPU's and wrote the entire Software Pyramid from the ROM Loader to the Bootloader to the OS.
I might be dumb, but not that dumb.

 

[SicivicSi]

I'll see what I can do. Not to brag but I have designed CPU's and wrote the entire Software Pyramid from the ROM Loader to the Bootloader to the OS.
I might be dumb, but not that dumb.

Would the tach signal be through can bus or just from a crank position signal like older hondas?

 

[Frapuchini]

This is the first time that I attempt anything with a car. I got pretty good electronics and software knowledge. I think it's going to take more than a year to decode everything. But that will open so many doors to these new platforms.

I think this device should be sufficient for this task. It's relatively inexpensive.

If I'm not wrong, I believe there are two CAN BUS in the vehicle, and both end up in the head unit.
That's where I plan to connect this device to.

 

[Frapuchini]

Would the tach signal be through can bus or just from a crank position signal like older hondas?

I need to look at the schematic. But I believe it's through the CAN BUS.

 

[Frapuchini]

Actually, take that back. Comma did work with the ECU and message frames they needed for self-driving. But there are whole swaths of codes and variants of packet payloads per trim that this misses, especially on the interior side (radio, suspension, gauges, HVAC, EPS.

This got me started, and I used super-thin t pins in the backside of the radio connector with FCAN to tap the data. I’d recommend a UTP 2-wire setup with a connector on the other end of your choice.

Yes, I think the back of the radio connector has access to the two CAN networks in the car.
B-CAN and F-CAN.

I'm not sure which one is the CAN BUS of interest. I uploaded the head unit connectors pdf. This file came from ic1101 in GitHub. ic1101/datasheets/headunit-connectors.pdf at main · librick/ic1101

 

[SicivicSi]

I need to look at the schematic. But I believe it's through the CAN BUS.

Thank you very much, thats what I thought so it would probably make more sense to just put a haltech digital dash in

 

[KensBlueGenX]

This is the first time that I attempt anything with a car. I got pretty good electronics and software knowledge. I think it's going to take more than a year to decode everything. But that will open so many doors to these new platforms.

I think this device should be sufficient for this task. It's relatively inexpensive.

If I'm not wrong, I believe there are two CAN BUS in the vehicle, and both end up in the head unit.
That's where I plan to connect this device to.

Yes, there is a "F-BUS" and a "B-BUS". Both of them use the CAN protocol.

Both of them communicate with the audio head unit. The gauge cluster acts as the master gateway.

Section 41 of the service manual describes them in a bit of detail.

 

[Frapuchini]

Yes, there is a "F-BUS" and a "B-BUS". Both of them use the CAN protocol.

Both of them communicate with the audio head unit. The gauge cluster acts as the master gateway.

Section 41 of the service manual describes them in a bit of detail.

That's helpful, can you please send me a link to that service manual?

 

[mrburgerUS]

Would the tach signal be through can bus or just from a crank position signal like older hondas?

It’s CAN. I know because another project but I will not divulge the details

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