?custom pid help?

[rnl35thss]

I think that's what I need. I'm trying to log my AFX wb through my non-existent EGR position. I've searched and I'm sure I'm looking right at what I need, but I guess I'm just doing something wrong.. This thread has a great explanation of the math http://www.hptuners.com/forum/showthread.php?t=14570 , but I'm missing something on setting it up. I have everything hooked up, and can read the WB output as volts in the scanner using a config that I got from this thread, http://www.hptuners.com/forum/showth...&highlight=egr . I think I've molested that config a bit. I hate to ask, but if anyone could help me out with this I sure would appreciate it.
Thanks, Donnie

[rnl35thss]

I think I'm getting close.(Thanks 5 Liter Eater). I am reading afr in the table (pretty sure). Can't seem to get it in the chart as afr, only volts 0-5. Is it possible? I think the light bulb upstairs is starting to flicker.

[rnl35thss]

Forgot to add new config. Screwed it up and named it the same, but its changed.

[rnl35thss]

moved from a flicker to a slow glow. Pretty sure I got it.

[5_Liter_Eater]

User defined PIDs are kept in the "VCM Scanner.cfg" file. Will need that to help.

[rnl35thss]

Sorry to be dumb, but I can't seem to find it. In the VCM Scanner file?

[rnl35thss]

Thanks 5 Liter Eater, I think my problem was that I was not entering the funtion string correctly. Also got it reading in the chart. If you have a chance I would love it if you could take a look to see if you agree that its right.
Thanks, Donnie

[5_Liter_Eater]

Search your hard drive for "vcm scanner.cfg" and attach it to the thread.

[rnl35thss]

Is this it?

[5_Liter_Eater]

Yes, thats it. Now I can see your log with your user defined PID.

I'd drop the equivalence ratio from the table, it's just taking up extra bytes and not being used. If you have an Air Fuel Ratio Commanded Lo Res I'd use that instead of the High Res. The High Res takes up more bytes.

I get two unsupported paramaters in the table when I open the log. Whatever is above the AFX WB and whatever is above the AFR Commanded Hi Res.

Assuming you followed the equation right then your AFX WB PID is OK. It's [PID.2811]/(5/7)+9 so that means you have the AFX configured to have 0-5V read from 9-16 AFR? Is that correct?

Next you will need a user defined AFR Error PID because (last time I checked anyway) even though you define the custom PID for the WB as an air fuel ratio sensor, the built in AFR Error PID does not recognize it as a wide band because it's not coming from EIO. Info that here: http://www.hptuners.com/forum/showth...highlight=deux

[rnl35thss]

Thanks!!! The only reason I was using that config was because it was set up for logging the WB through EGR. It's not my config at all, so I'm not sure about the unsupporteds, but the WB equation is right for voltages and range. I'll go with your other advice too. Thanks . Now that I've got it figured out I'll use it in my other configs and work on that AFR error.
Thanks again, Donnie

[5_Liter_Eater]

Beauty. One thing. Especially when piping the WB through the EGR or AC you tend to run into grounding offsets that cause HPT to be different than the WB gauge even though the formula is mathmatically correct. What I do is start the car, let it idle, and put the laptop close to the gauge and take 3-5 digital pictures to see what the difference is. If it's within 1/2 point you're OK to adjust the equation. If it's off by more you may have other problems. So if the average of the pictures puts HPT reading .3 leaner than the gauge, subtract .3 from the 9 in your equation and do it again until they are very close. Then, when you create the AFR Error PID you will end up using that same equation in that function. Remember to make the change in both PIDs if you ever change the formula.

[rnl35thss]

Great! Thank you so much for your help. This thing has been kicking my butt for a while.
I think I had the parenthesis in the wrong place in my equation all along . Thanks again on the offset advice, I will definately check that.
Thanks again,
Donnie