Thread: Official PID Documentation?

You cannot buy the drafts, they still can change. You can only buy the standards.
Have a look here: http://www.sae.org/technical/standards/J1979_200705
This is what's changed between 2002 and 2007: http://engineers.ihs.com/document/ab...QIACAAAAAAAAAA

While you could buy the spec, really all you need is:
http://en.wikipedia.org/wiki/OBD-II_PIDs

For instance, you send ascii "010C\r" (the \r being a carrage return), and it will return a string of asciii represented bytes. I don't have my logs infront of me, but it is something along the lines of: "63 41 0C 03 2C" where 41 is your mode (with bit 6 flipped on), 0C is your request type, 03 2C is your actual responce, which according to the table on the wiki page you convert by doing ((03*256)+2C)/4 which would be 203rpm. (a bit low, but hey I didn't figure it out in reverse :P)

Although the informatiion is wikipedia is correct, it is outdated and incomplete.
It's missing pids 4F, 50 and 53 through 87.
And the description of the can-id's is very incomplete to say the least, there are more id's that are valid.
Where's the description of service 6? Or the ecu name in service 9?
If you want to have all of the specs you need the official document.

Hmm, guess I never noticed because my car only supports about 10-15 of those PID values heh.

Something I forgot to add. If you happen to have that information p2psmurf, you should post it on the wiki. The wiki is nothing without the sharing of information that could help others greatly

What information is missing from wikipedia (that most cars probably support)?

When I do a mode 01, pid 00, my response is:

41 00 B3 3E B8 10

So that means I support:
1 monitor status
3 fuel sys status
4 engine load
7 long term fuel trim bank 1
8 short term fuel trim bank 2
11 intake manifold pressure
12 engine rpms
13 vehicle speed
14 timing advance
15 intake air temp
17 throttle pos.
19 o2 sensors pres
20 o2 bank 1 sensor 1
21 o2 bank 1 sensor 2
28 obd standard conformance

But this doesn't make sense...7 & 8 are supported but 6 & 9 aren't?

I could've sworn the scantool.net app shows engine coolant temperature.

Am I parsing it incorrectly?

^ Don't know what happened above but my car now responds with a different 32bit mask for supported PIDs...which is now more logical.

However, 0021h, 0041h don't return any data....my car only supports that little reporting? How can I get more info???

little endien
B3 3E B8 10 = 10B83EB3
------31-------------------------------------0
Binary: 00010000 10111000 00111110 10110011

0 = supports this bitmask page
31 = supports next page (Mode 1, PID 32...PID 64...)

Your's supports 1,4,5,7,9,10,11,12,13,19....

Originally Posted by Curiosity

little endien
B3 3E B8 10 = 10B83EB3
------31-------------------------------------0
Binary: 00010000 10111000 00111110 10110011

0 = supports this bitmask page
31 = supports next page (Mode 1, PID 32...PID 64...)

Your's supports 1,4,5,7,9,10,11,12,13,19....

Are you sure I'm supposed to interpret the response as Little Endian byte-order? The new PID mask I get back matches up with when data is returned. The original PID mask I've posted above has never come back which leads me to believe there was an error in transmission (I excluded a null byte received which the ELM docs say to ignore).

Interpreted as Big Endian with bit 31=pid 1 support status, 30=2, ..., 27=5, ..., 0 = pid 32 supported and sending a PID request for an unsupported PID, the ELM327 correctly responds with "NO DATA".

The response I now get on mode 1, pid 0 is this:

41 00 BE 3E B8 10

and I interpret as:

[12/12/2008 3:42:23] Supported PIDs: 1 3 4 5 6 7 11 12 13 14 15 17 19 20 21 28
[12/12/2008 3:42:23] Supported PIDs on [Elm327 Interface, COM3 Open, ELM327 v1.3 found]:
0101: Monitor Status
0103: Fuel System Status
0104: Calculated Engine Load
0105: Engine Coolant Temperature
0106: Short Term Fuel Trim (Bank 1)
0107: Long Term Fuel Trim (Bank 1)
010B: Intake Manifold Pressure
010C: Engine RPM
010D: Vehicle Speed
010E: Timing Advance
010F: Intake Air Temperature
0111: Throttle Position
0113: O2 Sensors Present
0114: O2 Sensor: Bank 1, Sens 1
0115: O2 Sensor: Bank 1, Sens 2
011C: Conforming OBD Standard

Oh yes, you're right. I flipped them for binary access. Was wondering why at least enough for a 4-cyl wasn't there. It's not really little or big endian. All bits are in left to right order, which is what you've got now.