Issue to delete DTC with ADCS

[Kahlua85]

Hi everybody.

I'm trying to delete DTC's using the Automotive diagnostic command set. Unfortunately I have an Issue with the "clear emission related diagnostic Information" function.

This is a part of my work:

I'm not shure why it doesn't clear the dtc. In my Frontpanel i use for the DTCs out an array of Strings. That part works fine and it gives my the trouble codes. But it doesn't clear the error codes when i push the clear button. Is it because of the Array constant with a String in the second case structure? Does anyone has an idea to solve the issue?

Thanks in advance!

[Hooovahh]

What are the DTCs set and what is their statuses?  Lets say I have a DTC set that is "Low Battery Voltage" because my batter is at 9V.  Sending the Clear DTCs command, won't do anything because my battery voltage is still low.  You can't clear a DTC that is active.  That's why I'm wondering what the status of the DTC is.  Is it a historic DTC?  Or is it set right now?

[Kahlua85]

Well I unplugged the oxygen sensor and the MAF Sensor as well to provoke an error. Then I checked the DTCs. That programm recognized the errors so it worked. I put everything togehter and checked if the errors were still there and that was the case. So I tried to clear the dtc but nothing happend unfortunately. Btw is there an other way to check if the clearing of the DTCs work? 

Greetings Kahlua 

[Hooovahh]

Typically I'd say perform a clear, then read it back.  If it didn't clear, then the DTCs must have been set to active.  Keep in mind that the DTC Descriptor needs to be properly set.  The default is 3 bytes for length, 1 for status, and using Motorola byte order.  This is the most common configuration but it might not be what is needed for your application.

[Kahlua85]

Thank you so far Hooovahh. I think i have to do it with the try and error way. I also added the dtc descriptor just in case it is why it doesnt clear.

Greetings Kahlua