More PIDs for Torque App

Enroute

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Jul 21, 2020
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Miami
Great info. I will try the oil pressure PID you provided. I was looking at at a class 2 listing in hptuners.com forum under “PIDS” and saw that the [GM] extended pid for misfire count on cylinder 1 and 2 were swapped. I set them up with their respective history pid on the dash board and it appears that the class 2 listing I reviewed was wrong. The [GM] extended pid in Torque seems correct for their respective cylinder as the current count switches properly to the history pid. Unless the history pid is swapped as well. I will look at that tomorrow. Where you able to find any additional PIDS for the lm7? I am going to set up the TCC PIDS tomorrow and see how they go.

That same class 2 pid list listed your oil pressure address but with a different equation. Will update and see how that goes as well.

I have also read, I think it was in the class 2 forum in here that the misfire info seems unreliable and that the individual stopped even using them on the dash board. Has that been your observation as well?

Did a torque scan today and tried to email it to myself and nothing was attached and I got a note saying the proposed attachment had zero bytes. What am I doing wrong? I did the short scan as I did not have the hours it says it takes to complete.
 

TJBaker57

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Aug 16, 2015
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Did a torque scan today and tried to email it to myself and nothing was attached and I got a note saying the proposed attachment had zero bytes. What am I doing wrong? I did the short scan as I did not have the hours it says it takes to complete.


I am fairly sure this feature has never worked!! I intend to run a scan using the serial terminal app that has been so useful to me. With that app I know the session log will retain the data for inspection. Everytime time Intrued Torque Scan I found the same end result you did, no way to retain any potential discoveries.
 

TJBaker57

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Aug 16, 2015
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have also read, I think it was in the class 2 forum in here that the misfire info seems unreliable


My memory is unclear on the misfire business. I remember reading somewhere a little more detail about how the 'counts' are tallied and can only now remember that it was not in a way I would have thought. There is something about cycles and a timeframe?? At any rate as far as my Trailblazer goes, twice the misfire data has pinpointed a failed coil for me.
 
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TJBaker57

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That same class 2 pid list listed your oil pressure address but with a different equation. Will update and see how that goes as well.


My equations generally are built on the notion that these sensors are returning absolute pressure an thus reflect that in the calculations. I could be incorrect on that assumption. I am right now hashing about the AC High pressure sensor data and trying to resolve that one.
 

Enroute

Member
Jul 21, 2020
55
Miami
Latest update in PIDS for my LM7. My fear that the downloaded [GM] extended PIDS for misfire current count on cylinder 1 and 2 being swapped was confirmed today (post#121). Placed the two cylinder current count next to their respective history and indeed the misfire current count on cylinder 1 cycled to the history for cylinder 2 and visa versa. Watched the remaining cylinders and their respective current counts and history and they cycled properly. Wanted to post this for others who may be trying to track down a random misfire without a code as this issue may cause them to chase the wrong cylinder.

In addition, I did try the revised address and equation for oil pressure with no response. Any additional thoughts on that? Thank you for all your help!
 

Enroute

Member
Jul 21, 2020
55
Miami
Any way you could elaborate on the serial terminal app procedure for scanning that you mention in post#122? I would, and maybe others would find that very helpful. Thank you
 

TJBaker57

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Aug 16, 2015
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same class 2 pid list listed your oil pressure address but with a different equation.

What is the equation you found in that listing? I have seen one listed I believe in Torque for Oil Pressure 'A*0.578'...
In my Yukon with key on engine off the return value from the oil pressure pid is $1B, convert to decimal is 27.... 27 * 0.578 = 15.606 PSI with the engine OFF! That right there is enough reason for me to toss that equation.

I made my oil pressure pid based on an SAE document that gave a resolution of 1 bit = 4 kPa oil pressure. So there I have "A*4" so far. Then I want to display as PSI so the conversion from kPa to PSI is .145038 so I then came to "A*4*.145038". Rather than combine multipliers I like to leave it all laid out so I can see where they each come from. If you were to combine them you would note 4*.145038 is right there close to the 0.578 Torque had as equation. The last step in my equation adjusts from absolute pressure to gauge pressure by removing the standard atmosperic pressure of 14.7 (even though my local atmospheric pressure is just 10.8)
 

TJBaker57

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Aug 16, 2015
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In addition, I did try the revised address and equation for oil pressure with no response.

Did some more research and it seems like you will not get an oil pressure pid to work on your 2002. According to schematics for your 2002 the oil pressure sensor is a single wire sensor wired directly to the instrument cluster. Thus, unless the instrument cluster is broadcasting that data on the bus it is a dead end.
 

Enroute

Member
Jul 21, 2020
55
Miami
Yes. Torque says under the edit PID function to leave header blank for “auto”. If the address was correct, would I not get at least some response all be it and incorrect value? Torque shows “no response” as it lists the PIDs. This is the post I saw and is why I referenced it.

PID: 22115c
Min Value: 0
Max Value: 100 # This puts the needle at 12 o'clock at 50 psi
Scale: x1
Unit: psi
Equation: (A*0.65)-17.5 OBD Header: Auto
 

Enroute

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Jul 21, 2020
55
Miami
Thank you so much for your efforts. We will let this die unless I see it being broadcasted somehow. I have really learned great amounts about my LM7 and have all of you guys to thank.
 

TJBaker57

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leave header blank for “auto”

Screenshot_20200731-222543~01.png


Hmmm,,, I got 'Blank, Auto, or HEX. If blank Torque will send the pid out with standard header followed by mode and pid as written in the 'mode and pid' field. If that fails it will not try other methods. When set to Auto if the initial attempt fails Torque then appends '01' to the 'mode and pid' and sends that out. Frequently this alternate is succesful. Indeed, today I recorded a Torque Scan session and every pid the scan tries out is sent with that '01' appended. Every one. In the past I found mixed results with this '01' appended vs not, I even made a corrective post noting this. For my own use, any time I have a pid failure I try adding the '01' to the pid myself in the 'mode and pid' field.
 

TJBaker57

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Equation: (A*0.65)-17.5 OBD Header: Auto

I have seen this one also. Can find no logical basis in it so I think it was derived by trial and error. Another I have seen recently takes the offset off of 'A' first, then applies the scaling/conversion.... (A-27)*0.58
 

TJBaker57

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Aug 16, 2015
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Any way you could elaborate on the serial terminal app procedure for scanning that you mention in post#122? I would, and maybe others would find that very helpful. Thank you

This will take me a short while to get it all worked out. Did the short (10 minutes) Torque Scan today on the Yukon and recorded it all. I have an advantage having 4 ELM327 as well as 2 OBD2 splitters and 2 smartphones. So one can be running an app or whatever while another ELM327 and phone record the bus.

There were some 4128 pids rejected and 69 got a response. Looking at the pids tested I can only assume these are pids that may have returned a value on some vehicles. But they skip all manner of pids I know are in there.

Having 65535 possible pid values it makes sense to me to concentrate on blocks where other pids are known to be. And just getting a response is only a beginning. You still have no idea what data may be in there or what form it may be in.
 

Enroute

Member
Jul 21, 2020
55
Miami
Wow! I did read that wrong. That is a huge piece of info, critical in my option. So if I understand correctly, the best entry in the header field is always “auto” so it will try and resolve with additional attempts with the 01. Then try to add the 01 manually to try and get it to resolve. Is that it? Outstanding info. Thank you again so much.
 

TJBaker57

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Aug 16, 2015
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Having 65535 possible pid values it makes sense to me to concentrate on blocks where other pids are known to be.


Yesterday I scanned 1024 possible PIDs, $1100 to $14FF on the 2005 Yukon LM7. At 2 PIDs per second it takes less than 10 minutes. Ran the scan twice to get a full set of responses, sometimes the Bluetooth gets behind and drops a line here or there. I ran the scan using a listing of PIDs generated in spreadsheet and pasted into the terminal app. Looks like this ready to send in the terminal app....stretches on for 1024 PIDs...

Screenshot_20200802-071916.png


Again I turn to Google Sheets to crunch the data. Got positive responses on 179 with somewhere in the neighborhood of 120 of them being previously unknown to me. 15 of the PIDs at first responded with a 7F response type 23 which according to the document at FastFieros is "routine not complete". That response was immediately followed by a positive response. Never seen that before.

Some 55 of the newly discovered PIDs return 2 byte values, these are typically things that require a higher value/resolution like rom, misfire counts, injector command in milliseconds.

I ran the scan with KAEO (key accessory eng off). I will scan the resulting PIDs in other states of operation such as with the engine running while parked, then running with vehicle in motion. By comparing the values obtained I can perhaps detect which PIDs are motion related vs which may be engine but not motion related and so on.

Further along in the process I import a listing into Torque for real-time observation. They still aren't identified at that point, just raw values but watching them while flipping switches and running the engine or driving the vehicle helps to identify a PID here and there. Here's a shot of such an operation from last year where I was looking at individual bits...

Screenshot_20190820-152440.png
 

TJBaker57

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Just ran the same 1024 PID scan on the 2002 TrailBlazer and picked up 79 more PIDs that were not previously on my listings to evaluate.

Whew!
 
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mrrsm

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Last edited:

TJBaker57

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Tom...

Is THIS information anything you can use? It comes from ScannerDanner and the Topic was apparently "Lean to Rich Threshold issues for the 2002 Chevrolet Trailblazer 4.2L Engine":


View attachment 96013

I had that mode $06 document somewhere but had not dug into it. Definitely useful to know Torque app has muffed up description of the data for TID $02. Naturally it also led me to pull down mode $06 data in my terminal app and learn how to interpret the data that is returned..... Also useful. Not so much for this thread, but we ARE in the right section !! :wink:

As for PIDs,,, I have now scanned ALL the possible PIDs from 0x0000 to 0x24FF. I have no idea if there's anything above there but of course will scan now that I have a system up and it's easy to do. I have a list of 250 that have given a positive response. I've been looking at a set of 6 PIDs , sequentially numbered. I suspect of course related to our 6 cylinders but what? We already have the injector command in milliseconds and the misfire counts so what else?

Screenshot_20200806-091629~01.png

When powered up they start at zero. Start the engine and they jump up then slowly rise for maybe a minute or so until they plateau. Tap the pedal and they drop. Hold at higher rpm and they hold lower (not seen on this graph). Turn the key back to accessory and most jump high but not to the same level and in different order each time it would seem so far. Turn the key back to run and they reset to zero. The high jump is likely not significant as it happens when power to injectors, coils, some but not all PCM circuitry is being interrupted and seems likely to induce some erratic data, as well as only being seen in accesory position after the engine has run.

Could this be a current draw of the injectors? We know the PCM has that value as there is a DTC for an injector overcurrent, P0201 thru P0206. But this value returned is a 2 byte value capable of 0 to 65535 decimal. Would you need that much resolution for a simple 4 amp overcurrent detection? Seems unlikely.

These are the voices in my head.
 
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Enroute

Member
Jul 21, 2020
55
Miami
Thanks again for all the knowledge you have put forth. It has helped me greatly to really get to the bottom of my LM7 issues. I have a issue with my IAC position pid reading zero all the time. I have tried other PIDS I have found online with most having no response. The extended [GM] pid is set to the following

[GM]IAC PositionIAC Pos0x221172A0255Auto

Any ideas on this? Have you found a different pid for the LM7? All I have read says it should have at least 5% at idle.
 

TJBaker57

Original poster
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Aug 16, 2015
2,900
Colorado
Thanks again for all the knowledge you have put forth. It has helped me greatly to really get to the bottom of my LM7 issues. I have a issue with my IAC position pid reading zero all the time. I have tried other PIDS I have found online with most having no response. The extended [GM] pid is set to the following

[GM]IAC PositionIAC Pos0x221172A0255Auto
Any ideas on this? Have you found a different pid for the LM7? All I have read says it should have at least 5% at idle.
I will have a look and post what I find. I can't remember having looked at IAC.
 

TJBaker57

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Aug 16, 2015
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I've been looking at a set of 6 PIDs , sequentially numbered. I suspect of course related to our 6 cylinders but what?

Replying to myself now!! What does that tell you?

So I was just having anlook at the [GM] pids that come with Torque with the notion of importing to Car Scanner and happened upon a set of 6. 'Balance Rate'. Just maybe this is my set of 6 pids. Will apply that equation and have a look but I am hopeful this is it.
 

Enroute

Member
Jul 21, 2020
55
Miami
Great. Thank you. Most online info relates to IAC counts. Did not see a PID for that anywhere for my LM7. Not sure this motor even does that. Want to make sure I am looking at the correct output info before messing with anything.
 

TJBaker57

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Aug 16, 2015
2,900
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Replying to myself now!! What does that tell you?

So I was just having anlook at the [GM] pids that come with Torque with the notion of importing to Car Scanner and happened upon a set of 6. 'Balance Rate'. Just maybe this is my set of 6 pids. Will apply that equation and have a look but I am hopeful this is it.

Continuing my own conversation...

Everything I find online that talks of balance rates seems to apply to diesels so mybe that's not it.
 

TJBaker57

Original poster
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Aug 16, 2015
2,900
Colorado
Thanks again for all the knowledge you have put forth. It has helped me greatly to really get to the bottom of my LM7 issues. I have a issue with my IAC position pid reading zero all the time. I have tried other PIDS I have found online with most having no response. The extended [GM] pid is set to the following

[GM]IAC PositionIAC Pos0x221172A0255Auto
Any ideas on this? Have you found a different pid for the LM7? All I have read says it should have at least 5% at idle.
I'm looking at that 221172 and discovered that the GM pid set seems to expect a single byte return. However, 221172 returns a 2 byte value. Will need to look at this and determine the units, scaling, offset if any, and so on.

Screenshot_20200807-164557.png
 

Enroute

Member
Jul 21, 2020
55
Miami
I am going to try and input your equation and see what I get. I have played with it today with no luck. Do you have a pid list for the LM7?
 

Enroute

Member
Jul 21, 2020
55
Miami
I see what you mean about the two byte value. With your equation (A<8)+B entered it returns
A=0, B=38 so 0+38=38. It does range between 33 and 40 at idle so I am not sure exactly if that is count or % position or what. At 1500 rpm it goes to 50+ And at 2500 rpm it hits close to 100. Not sure but that seems to make sense I think. Will continue to watch and report.
 

TJBaker57

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I see what you mean about the two byte value. With your equation (A<8)+B entered it returns
A=0, B=38 so 0+38=38. It does range between 33 and 40 at idle so I am not sure exactly if that is count or % position or what. At 1500 rpm it goes to 50+ And at 2500 rpm it hits close to 100. Not sure but that seems to make sense I think. Will continue to watch and report.

I'm still looking at it. My 2005 LM7 comes back at a decimal value of 310 but I haven't driven around with it yet. I need to record some data nd see the range I get. Additionally, the value we are seeing likely needs further processing by some equation since 2 bytes has a range of 0 to 65535.

It is also possible that this PID on our LM7s is not the IAC at all but some other parameter alltogether.
 

TJBaker57

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Aug 16, 2015
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Here is my Trailblazer graphed with Desired Idle, IAC, and engine RPM. (The display reads 'Idle Speed' in place of Desired Idle Speed for some reason)

Screenshot_20200808-082323.png

I have to say I am impressed with the Car Scanner Pro app thus far. Looks very useful for data recording & analysis.

I looked with the TECh 2 and cannot find any occurrence of an IAC parameter so that's no help in determining what the final output of the IAC parameter should be. Did you say you saw it relresented as 'counts' and/or a percentage?
 

Enroute

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Jul 21, 2020
55
Miami
Thanks again TJ for all your work with this PID stuff.

I was reading on HPTunners in a forum post called IAC position PID that it is steps/counts that is displayed ranging from zero to 320. It also states that the desired reading at warm idle is between 30 and 50. Mine starts at 33 and climbs to around 40 as it continues to idle while warming up. After driving, mine comes back to 38 to 40 and holds at idle.

I need to clarify a previous post relating to the “B” byte from my LM7. All the readings I stated where standing still not under driving conditions. Today I logged the pid and saw as high as 185 at 2500 rpms with a TPS position of 48%. I am trying to locate where I read anything about this output being a % other than a PID for IAC motor position which I am pretty sure is not a working PID for the LM7. Will continue to review as I think it might have been in a post from EFItunners.
 

Enroute

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Jul 21, 2020
55
Miami
For what it is with, this PID 1190 works on my LM7. KOEO returns a value for A=20.0 B=-1.0 C=-1.0. Engine on idle closed loop A=17.0, trans to drive no speed A=17.0,
trans in park 1500 rpm A=2.0 to 4.0, 2000 rpm A=9.0, return to idle A=17.0. Hope that helps
 

TJBaker57

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was reading on HPTunners in a forum post called IAC position PID that it is steps/counts that is displayed ranging from zero to 320


I think my 05 LM7 is fully drive by wire and as such likey has no IAC at all?? So not sure what seeing a static 310 in my 1190 pid might mean. I'll keep logging it and watch for any changes.


I haven't spent much time evaluating potential PIDs on the Yukon LM7 as compared to the TrailBlazer LL8 and couple that with an with an almost overwhelming number of PIDs to investigate and the result is I haven't much to offer for the LM7/Yukon presently.

Your 2002 and my 2005 likely share a bunch of pids but may also have pids unique to that iteration of the engine/control system. Have you thought of scanning yours in a manner that would allow us to compare results? Earlier here in this thread I posted about my scanning method. I know you tried the Torque scan but that has limited use as the results seem to be inaccessible after the scan. If your interested I can detail the procedure. If memory serves you already have the OBD adapter. The only other piece needed is a free app and the instructions. I use google spreadsheets for analysis of the result and can setup an online spreadsheet to process the results of a scan.
 

TJBaker57

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Aug 16, 2015
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@Enroute

Here is the list of what PIDs replied to my scan of the 05 Yukon LM7 in the range of 0x1100 to 0x14FF.

Some return a value, some have always just returned a zero value. Some are/were already known, many are not.

Thought you might compare with your scans to see which are in common with your 2002 LM7.
 

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  • Yukon 2005 LM7 1100 to 14FF.txt
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Mooseman

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Dec 4, 2011
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That can be useful for someone having overheating issues. too bad there isn't a way to make it hold that the fan speed request.
 

TJBaker57

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That can be useful for someone having overheating issues. too bad there isn't a way to make it hold that the fan speed request.

It may just be my fan, I know mine never fully releases, but as seen mine takes a minute or two to come back down after it engages. I drop a few degrees if I tap the 100% button a couple times. There is a "tool present" message that can keep it active but needs to be sent something like every 3 seconds.

I can also cycle the front axle disconnect, fuel pump, Evap vent and/or purge valves, and A/C relay.
Could likely uncover a few more as well. Other than the fan I think these are best reserved for diagnostic purposes, and the fan should likely not be keyed up at high RPM. I imagine the normal functions of the PCM prevent too much fan engagement at high RPM.
 

Mooseman

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Dec 4, 2011
25,327
Ottawa, ON
It does take a minute or two for the silicone fluid to move from the clutch to the reservoir and yours does seem to be responding properly.

Probably the easiest way to command 100% fan is to wire 12v+ via a switch to the relay output leg. Useful when towing in hot weather. I might even swap the EV clutch from the 07 into the Saab for towing. Thermal clutch isn't quite cutting it.
 

TJBaker57

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Aug 16, 2015
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My EV clutch never quite releases. I suspect internally the valve doesn't quite seal, allowing some fluid to.continually bleed through. I get absolutely no change in fan speed when I command a low value like 25%. I thought maybe by exercising the valve open and closed it might improve. Time will tell.
 

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