How to fix open/short in CAN High and Low line?

[corneliusw]

I am having a CAN Bus issue with creating a connection according to my scanner. Errors are either showing possible causes open/short in PSB + LCA + EPB CAN high and low line or Open in CAN communication line with poor connection the ECUs incorrectly occupy the CAN bus.

How do I perform an inspection so I can figure out if it's a module or a specific wire that needs to be replaced?

 

[joegr]

I'd start by disconnecting the easiest modules to get to, and seeing if you can then communicate correctly with the remaining modules. If that works, plug half of the disconnected ones back in and check again.

 

[corneliusw]

I'd start by disconnecting the easiest modules to get to, and seeing if you can then communicate correctly with the remaining modules. If that works, plug half of the disconnected ones back in and check again.

Do I need to disconnect battery with each module removal, or is it okay to just have the vehicle turned off?

 

[arcman]

Here's my experience: My car was 'Totaled' by the insurance company over a part costing $1.46

You can unplug any of them with the car running. You'll just get an error on the dash. A scope helped a bunch in my situation. Start by checking for resistance on the can bus. Should be around 60 ohms. Lot's of videos on Youtube to guide you.

 

[corneliusw]

Here's my experience: My car was 'Totaled' by the insurance company over a part costing $1.46

You can unplug any of them with the car running. You'll just get an error on the dash. A scope helped a bunch in my situation. Start by checking for resistance on the can bus. Should be around 60 ohms. Lot's of videos on Youtube to guide you.

Ok will take a read. I have one error on dash now, "Check PSB". So if I disconnect the failed module the scanner would show 1 error vs. the current 5?

As the scanner shows there's issues with ESC (electronic stability control), EPB (electric parking brake), SCC (smart cruise control), CGW (central gateway), and OCS (occupant classification system).

Using your simple method I could eliminate a few of those by disconnecting the failed module that is causing the other modules not to communicate.

 

[arcman]

My car had multiple module errors, 5 or more at a time. It was one bad chip in the parking brake that caused all of those. When I disconnected the EPB, I only had that one module show on the display.

Do some more searching here for that error. I think a single PSB error was one that was tied to the fuel pump control module in the trunk. One forum member either posted or sent me this.

 

[corneliusw]

My car had multiple module errors, 5 or more at a time. It was one bad chip in the parking brake that caused all of those. When I disconnected the EPB, I only had that one module show on the display.

Do some more searching here for that error. I think a single PSB error was one that was tied to the fuel pump control module in the trunk. One forum member either posted or sent me this.

Is there a diagram that shows where all the modules are located? I know there's three computers top right under the hood, then there's the two modules under the armrest (airbag and can't remember the 2nd), and of course the fuel pump control module in the trunk. What other modules are there besides those?

 

[arcman]

Go back to my 'Totaled' post and scroll down to the C-CAN diagram. I added all the locations. If you haven't already, download the manual via Google search. Hyundai Genesis - Google Drive

 

[corneliusw]

Go back to my 'Totaled' post and scroll down to the C-CAN diagram. I added all the locations. If you haven't already, download the manual via Google search. Hyundai Genesis - Google Drive

For the Electric Parking Brake Module, it reads "Above Diff Yoke R side". Do you know where that is exactly located on the car? I am not sure what "Diff Yoke" is on a car. I've heard of a lot of terms, but that part of the vehicle is a new one for me lol. I was thinking the parking brake module would be under the car next to one of the tires. That's just a guess though.

 

[arcman]

The object with the white sticker is the parking brake module. Tough to get out but doable. It's bolted to a bracket that holds it to the crossmember. Underneath it is the differential and the 3-bolt yoke (that connects to the driveshaft).




If you suspect you are getting errors from the EPB, first test it by disconnecting connector FF02 in the right rear wheel well. The cable that leads to the rear passenger seat will need to be jumped with two short wires, pin 2 to 16 and pin 3 to 15. Without those two jumper wires, the CAN bus won't be completed and most likely nothing will work. At that point you've removed the EPB from the system and you will get a single error on the dash. If you have other errors still showing up... it's not your EPB.

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[corneliusw]

Thank you for the information. Is the rear suspension that is shown in the picture directly under the car? I am trying to pinpoint where that photo is. Need to see if I can just put it on a jack or will need to get it on a lift depending on where it's at.

 

[MTAuto]

Arcman, I have having a similar issue with my 2018 G80. In one of your posts you mention a Google Drive link that has information on module locations and more importantly pin mapping. For example, I need to know which are the pins 2, 3, 15, and 16 so I can perform the same test mentioned in this thread. Thanks much!

 

[arcman]

Hyundai Genesis - Google Drive

drive.google.com

 

[MTAuto]

Hyundai Genesis - Google Drive

drive.google.com

Thank you!