E35 Mode-22 PIDs

Does the LBZ/LMM ECM not support mode-22 PID request? Or am I just being stupid and doing something wrong.

If I send it a mode-22 PID request for a known valid PID (say, fuel rail pressure ($0023), 7E0-03-22-00-23)....and it just sends back a negative response (service not supported). :unsure:

I know that some ecms get pissy with out trailing zeros for some things, ie they expect certain data lengths of 7 or 8 bytes..... but i would assume mode 22 works? I was under the impression that EDGE use mode 22 exclusively. Atleast for everything that I have ever messed with they have.

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Originally Posted by Chavez91

I know that some ecms get pissy with out trailing zeros for some things, ie they expect certain data lengths of 7 or 8 bytes..... but i would assume mode 22 works? I was under the impression that EDGE use mode 22 exclusively. Atleast for everything that I have ever messed with they have.

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yeah I already tried padding with 00's. Still gives a negative response, mode not supported.

Edge uses DPIDs (mode $2C) on GM's, at least on the [GM] CAN controllers. Ive never checked on the GM J1850 controllers.

Dynamic PIDs is all I've ever used with E35. Kinda a pain to setup correctly, but flawless once ya get em stacked.

PS. Many PIDs different between LBZ to LMM..

Sent from my SAMSUNG-SM-G890A using Tapatalk

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Originally Posted by DURAtotheMAX

If I send it a mode-22 PID request for a known valid PID (say, fuel rail pressure ($0023), 7E0-03-22-00-23)....and it just sends back a negative response (service not supported). :unsure:

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Is it definitely Mode not supported? Or Parameter not supported?

Off the top of my head I can't remember on these if they support Mode $22, however GM tends to stick with Mode $2C as was posted above.

Your message format does seem valid though, it should only be a 16 bit Identifier therefore it would seem silly to have to pad with 00's to get the byte count up to a full frame.

Also with Mode $22 they tend to have pre-defined data streams (much like how the Dodge / Cummins ECM is).
So sending a Mode $22,$0A,$00 (just made that up) might actually result in the ECM sending back data for 4 or 5 different things in the response.

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Originally Posted by GMPX

Is it definitely Mode not supported? Or Parameter not supported?

Off the top of my head I can't remember on these if they support Mode $22, however GM tends to stick with Mode $2C as was posted above.

Your message format does seem valid though, it should only be a 16 bit Identifier therefore it would seem silly to have to pad with 00's to get the byte count up to a full frame.

Also with Mode $22 they tend to have pre-defined data streams (much like how the Dodge / Cummins ECM is).
So sending a Mode $22,$0A,$00 (just made that up) might actually result in the ECM sending back data for 4 or 5 different things in the response.

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Ross- sorry I missed this response!

Its definitely a "service not supported" negative response. Maybe GM simply just chose to not support it on the LBZ/LMM because all of their scan tools always just use mode $2C DPID groups anyways... it works on the LML though, and im 98% sure it works on the L5P too.:ermm:

With Bosch who knows, it's not GM's code so I guess they didn't have full control over it.