How to get Diagnostic Trouble Codes (or DTCs)?

[jaymik]

Hi, does anyone know how to get a list of Diagnostic Trouble Codes (aka DTCs) into Home Assistant?

The idea is that Home Assistant would automatically alert me if a code shows up on one of my vehicles, and ideally, it can log the code for historical reference.

Using my 2011 Honda CR-Z for testing, I was able to use Car Scanner with WiCan Pro through my network, and I also successfully retrieved some of the Standard PIDs (2f-FuelTankLevel) to log into Home Assistant. However, I'm now struggling to determine how to set up WiCan to obtain DTCs and have Home Assistant read them.

Any help would be appreciated!

[meatpiHQ]

@jaymik This is not yet supported, please check back in a couple of weeks.

Btw make sure you update to latest firmware version

https://github.com/meatpiHQ/wican-fw/releases/tag/v4.22p-beta

[AikiMaster]

Hi, is it possible now to somehow query the DTCs? Imnew with with wican pro, I'm testing new beta firmware with group based pids. Im using Mosquitto + telegraf + Influx3 core + Grafana. Would it be possible to show DTCs in Grafana? Sorry, may be to much for this particular topic.

Thanks in advance

[wambs]

@AikiMaster I'm the author of the Group Based PIDs. I'm also looking into DTCs as well. Stay tune....

[AikiMaster]

Thanks I will! If you need any specific testing, please contact. With the new terminal included in de UI, I've been able to query the DTCs, but is it possible to query publishing a command via mqtt? someting like

{
"cmd": "obd_query",
"data": "03"
}

and then wait response in a specific topic?

[wambs]

@AikiMaster thats a start. But there are a few issues with the current design of the WiCAN Pro for DTCs. The WiCAN Pro SW was designed to do calculations on values. One issue, is when you have more than 2 codes in a message, it will span more than one frame. DTCs format is universal, but the contents of the data is car manufacture dependent. So, decode for me is a two stage progress, using a new expression called RAW, it combines the DTCs into one big MQTT steam and sends to Home Assistant. Home assistant decodes the meaning of the codes. For my ford truck, I found the 300+ codes defined and my display the meaning of the code in home assistant.

[wambs]

@AikiMaster @jaymik I forked version of the WiCAN Pro SW, that one day I hope Mr. MeatPi will merge back into the Main repository. If you want to try this Beta See release below. It you don't like the Beta, you can always reload with the stable version V4.48
I have a new Beta release support for DTCs (Diagnostic Trouble Codes) - For details See - wambs#10
https://github.com/wambs/wican-fw/releases