1. I know m8, sure you have other things to do,
i am a working man also.

By the way, if you could just give me or us a documentation not a whole program,
just to know those pids and the addresses of the ECUs we could address and query
to get those pids would be very nice, i am a programmer and i can make my own
program to deal with those pids.

Best regards
-=LTi=-

2. Hi All,

I'm trying to properly understand the document attached with the ford enhanced PID's and their scaling.

Based on some previous research I did for TFT (Trans fluid temp), I was able to figure out the scaling for that value, and it does not seem to match what is in the document. So, either I'm misunderstanding the document, or the scaling is wrong.

Here's my original post about the topic over on scantool.net.

In brief, if I request the TFT data (PID 0x1674) the 8th and 9th bytes are 0x01 0xBB, which my scan tool and software tells me is 55.4F. According to the poster in the thread linked above, the correct scaling is to evaluate those two bytes as a single value, and simply divide by 8 to get the value. I.E. 0x01 0xBB = 443. 443 / 8 = 55.375

Now, the document tells me to evaluate byte 4, and multiply it by 31.25. The 4th byte is 0x10 or 16. 16 * 31.25 = 500.

What am I doing wrong?

SEND: 17 C4 10 F1 22 16 74 A1
RECV: 09 C4 F1 10 62 16 74 01 BB ED

3. Originally Posted by cherrybomb
In brief, if I request the TFT data (PID 0x1674) the 8th and 9th bytes are 0x01 0xBB, which my scan tool and software tells me is 55.4F. According to the poster in the thread linked above, the correct scaling is to evaluate those two bytes as a single value, and simply divide by 8 to get the value. I.E. 0x01 0xBB = 443. 443 / 8 = 55.375
The poster in the other thread is correct -- his procedure to calculate TFT in degrees F works. He seems like a smart guy.

The document in this thread meant the fourth byte past the header, but that would be wrong because TFT returns two bytes and the conversion is bogus. I wondered if the author meant to divide by 31.25 as a crude approximation of TFT in degrees celsius, but even that would be hard to believe. Sorry! Doesn't look like there's much useful there.

4. Originally Posted by joeyoravec
The poster in the other thread is correct -- his procedure to calculate TFT in degrees F works. He seems like a smart guy.

The document in this thread meant the fourth byte past the header, but that would be wrong because TFT returns two bytes and the conversion is bogus. I wondered if the author meant to divide by 31.25 as a crude approximation of TFT in degrees celsius, but even that would be hard to believe. Sorry! Doesn't look like there's much useful there.
HAHA! Yes, "that guy" seems to be on every board I am, and fairly active as well. Definitely a smart guy!

That post over on scantool.net is over a year old, and I now have my CarPC installed, and I'm actually able to mess around with this. In the time between then and now, I've been trying to get some sort of definitive document with the enhanced PID's and their scaling, but to no avail.

I don't understand why this is such secret information. I even had a few long calls with my local Ford dealer, and a couple Ford tech lines with no success. Most of them had no idea what I was talking about.

At least, it looks as though this document might have accurate PID's, but not the correct scaling. *sigh*

Also, I saw some hints that this data might be in the service manual, but I have it, on CD, and can't seem to find the data. Just the PID's by name, with no scaling.

This data can't really be that top secret, can it?

I guess I'll just have to keep asking for the correct scaling for each new value I want to evaluate. Seems lame though. *shrug*

5. does anyone have the GM enhanced PID list???

6. Originally Posted by NissanFreak
The software i used to get the scaling is Obdscan by Harrison. Some of the data values are converted wrong with that software, well i had the old version may have been resolved with the newest. Now, i have a reliable Obd II software. If you take a moment to download the attached toyota document and verify it with a toyota.

I may have to redo ford with the new Obd software i have.
Thanks NissanFreak!

I'd be happy to help if I can. The data I'm getting is from an OBDII interface which supports enhanced PID's, though I'm not sure how I can use that data to figure out the scaling.

I'd be happy to provide you data from my interface and software for my 1999 Ford Explorer if it would be of any use to you.

Thank you VERY much for your efforts. You should provide a paypal account, or some other way for folks to show their appreciation for your work.

7. I'm not quite sure how to use the data either... I have a C# app I wrote to test PIDs with and not sure how to form the raw serial message based on the document. could you give an example? i.e. in mode 01, i'd just send something like "01 0C" to grab the engine RPM, what hex string would I be sending for say, this one in the doc:

B2 - VOLTS = (BYTE3 * (5/255)) - Accelerator Position 1

if someone can let me know how to do this I should be able to find someone with a toyota to test on

8. Originally Posted by impala454
I'm not quite sure how to use the data either... I have a C# app I wrote to test PIDs with and not sure how to form the raw serial message based on the document. could you give an example? i.e. in mode 01, i'd just send something like "01 0C" to grab the engine RPM, what hex string would I be sending for say, this one in the doc:

B2 - VOLTS = (BYTE3 * (5/255)) - Accelerator Position 1

if someone can let me know how to do this I should be able to find someone with a toyota to test on
The exact hex string you send will depend upon the scantool/interface. You'll need to send a 3 byte header, and up to 7 bytes of data, followed by a CRC byte to verify your request.

The following page should be helpful with regard to this, you'll possibly need information from your specific interface as well. Note specifically the "MESSAGE FRAME structure" link.

http://obddiagnostics.com/obdinfo/info.html

9. yeah i'm at kind of a loss for how these vehicle specific PIDs work... like i said with my 2006 chevy silverado, i simply plug in my elm 327 based scantool, load up my C# program, open the port and send the byte string: "01 0C\r\n" and i get back the bytes "01 0C XX" where XX is the byte encoded engine RPM. i don't seem to have to send any kind of headers or anything. i thought that for the enhanced PIDs (like mode 22, 23, etc) would be just as simple, except with 2 byte PIDs. so something like "22 01 01\r\n" would get me the door ajar indicator or something.

10. Originally Posted by NissanFreak
I believe Toyota Powertrain Enhance Sensor Pids is based on SAE J1979 (686AF1 Headers ISO 9141) or (Cx33F1 KW2000) and uses Service Mode 01. So with your elm a simple 01 XX probable should work. Try any of the Pids on the attach list with a toyota. It might work.

Enhance GM/ford Headers are different and they use Mode 22 for powertrain.
I can come up with some Pids you can play around with your Chevy body contoller. You must adjust your headers on the elm interface. I will post some later if want to try them out.
ok so if i find me a toyota to test, again with this as an example:

B2 - VOLTS = (BYTE3 * (5/255)) - Accelerator Position 1

which one is my command bit to send? like on the most basic level, what serial message am I sending through my elm?

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