Checked this. On the G8 OS we were working on it was already enabled, but no SAE VSS for logging.Originally Posted by midgetracr
Checked this. On the G8 OS we were working on it was already enabled, but no SAE VSS for logging.
I tried this tonight turning the Wheel Speed Output to Enable but did not enable anything on the VCM Scanner...
I even then delete the .OS file so it would re-read the PIDs and deleted the VSS one and reloaded it, etc with no luck
Midgetracr would you mind uploading your tune file and scanner file to help us better understand exactly what you did?
From your description you are running exactly what i have, LS376/480 with the GMPP controller.
I have the speedo working but can not get the HP Tuner VSS to work so far, comparing your parameters to mine might help us learn what is the difference
Thanks
Current cal attached along with an HPL showing the speedo readout and my current .cfg file
I have looked for an HPL that shows small amounts of KR but cannot find one. I clearly remember reducing advance in several cells to kill a * or two of KR. Therefore I must have seen KR but cannot show a log to prove it.
Hope this helps. Please let me know if you need anything else.
Thanks for posting your files, i don't see anything obvious at first glance but i will go into it in more detail... it is really strange
also i see that you adjusted your Engine Diag limits for Max Airflow vs RPM as your MAF was maxing out...
On the dyno with mine last friday i had a similar issue, my MAF rolled off around 42... i haven't adjusted anything yet, although the tuning school instructor where i bought tuning the right way book suggested i try the same thing you did but haven't had a chance yet... with this change did you see a change in your MAF?
thanks
The "Engine Diag limits for Max Airflow vs RPM" was increased because the engine would intermittently go into safe or limp mode. It is my understanding that this function in the GMPP map is to limit engine performance if the MAF malfunctions.
In my case, the engine would suddenly shut down to idle in the middle of a race track straightaway. This is not a good thing when going 100 mph+ in front of a bunch of cars!
I added about 30% to the MAF limits and the problem has not reoccurred. It is interesting to note that my LS376/480 is 100% stock except for A) headers and B) a straight path for inlet air into the TB instead of the rippled neoprene hoses with lots of bends in most stock car setups.
The MAF calibration was not changed when these limits were increased. The MAF calibration has had significant changes from stock.
I should add to the above that logs clearly show that the engine had more air flow than those MAF flow limits were set to. It appears to me that the Stock GMPP flow limits were set to low. I am lucky that no one was hurt when the engine shut off on the race track. It happened twice on the same day. I did not go back on track till this was figured out, weeks later.
Interesting point, as all GM controllers or at least the dozens we work with, have the same MAF airflow/rpm limits of 300g/s at 7,000rpm.
Also interesting is that the delta airflow settings seem to sometimes contradict this by getting up to 512g/s at full throttle.
Back to the speedo, this is very odd...
I can not see anything different between midgetracr and my tune file that should be indicating his will have VSS PID on which he clearly now sees it on his logs, and i can still not see it on mine
Attached below is my tune file for comparison to midge's...
Bill / Chris,
could you take a look and advise as this is very odd, we both are running LS376/480 with the GMPP Controller and from the files seemingly have the speedo settings as far as outputs set the same (other than the values for actual number of pulses, etc)
It would be great if we could figure this out!
I was tempted to load midge's file down into my controller and only just move around the driveway to see if it could see speed, but encountered another weird item...
I decided to do a Read Entire of my tune back from the ECM, and it couldn't successfully do it!!! It kept saying at the end of reading it invalid checksum or and error like that! I have no problem uploading my configs, and of course originally did a Read Entire, what do you think???
Thanks
Last edited by alan91z28; 08-14-2009 at 07:35 PM.
alan91z28,
I will be trying me speedo this weekend when I get my car back. I get the Checksum error all the time with my GMPP E67. There is something slightly off with how the 2.23 beta pulls the data off ECM and then verifies it although that will need to be addressed through an email to Bill or Chris. I have already send them the corrupt file that is saved after the "Checksum" problem however it has never been resolved.
I'll cross my fingers about getting a working speedo in the VCM scanner.
I had an error almost all the time when writing a file into the VCM from my laptop. Bill suggested that I always use "write entire". This has worked 100% without errors since.
Could this be a factor in this VSS issue?
Possibly, but the hpt people would need to investigae that. I'm wondering if the GMPP ECM isn't proving the speed pid and it may have been added to you files midgetracr while you were connected to another ecm. I have only used my hpt with my gmpp ecm and it appears that they are all stored in one folder on my laptop. Do you thin there is any merit to this idea?
I have used my HPT on three different GM V6 VCM's in addition to the LS376/480. I've also had two different laptops involved. I suppose its possible that your theory is correct but I have no idea how to check.
I also tried to get help from GMPP but they absolutely refused to help on either the shutdown or VSS problem when I told them I had HPT. I can understand 100% that they would be reluctant to warranty broken pistons or valve train things if I had changed ignition advance or rev limit functions. On the other hand, how can their VSS functions not working as promised in their literature be a cost or liability to GM because I had used HPT?
This engine is a very nice piece at a good price. On the other hand, I was not happy with their "Support".
I haven't had time to test the Speedo yet, but I did determine that in order to get a clean read of the ecm without a checksum error I have to do a "write entire." If I do not, then there is no way to read the ecm. This would be a problem if someone needed to ready my ecm such as a tuner and I didn't bring the .hpt file with me so he could do a "write entire" before starting any tuning.
So my speedo is now working in HPT. Hurrah! I installed the new beta compilation and it worked.
Great. Your conclusion is that the write entire solved your problem?
I believe that first off, the new beta is required and deletion of the .os file then secondly, a "write entire" will eliminate any checksum errors when reading the tune on the ecm. I still don't have the KR pid.
I just tried this a couple of minutes ago as well on my '85 IROC with LS376/480.
I did a Write Entire of my present file and also deleted the .OS
I can now see vehicle speed and also was able to read back my file successfully from the ECM
My present config also had the Wheel Speed Output Enabled
I had previously deleted the .OS and it did not work to see speed
It seems to have something to do with writing the entire program back, maybe in combination with having the Wheel Speed Output Enabled. Faust did you also enable the Wheel Speed Output?
I also checked the ECM controls, nothing is available still on that
I also have a spare E67 now and am looking to get it programmed with the CTS-V and give that a try to see if that is a better way to go to have everything working in the scanner
Would someone be able to post which pins on the E67 are for VSS in, VSS out, and Rear wheel sensor out?Yes talk about 3 letter acronyms (TLA's and TIA's LOL!!!), now we are up to 6 letter acronyms RepTOS! SLA's!
RepTOS is "Replicated Transmission Output Shaft Speed Sensor (VSS/Vehicle Speed Sensor).
It is a signal that is "replicated" by the TCM and fed into the ECM as a VSS (Vehicle Speed Sensor) so the ECM has a speed signal. M6's feed the speed sensor signal direct into the ECM. The TCM mimics this after it processes the VSS from the trans out put shaft. (TOSS) There is also a TISS, transmission input shaft speed sensor.
HPT has enabled the speedo processing in the ECM to be changed from being fed by serial via the CAN from the TCM, to hardwired via RepTOS. (A4's and M6's mostly use RepTOS but not always.) Some truck A6's use it too.
GM terminology, but probably applies generally.
4,000 pulses per mile is sort of an industry standard for speedos.
So the aim is 4kppm from the ECM for the speedo. Or in metric countries, about 2500ppkm.
Hope that helps man!
Now if only the HPT gurus (the ones with the Guru pins) can somehow wake up the ECM VSS PID for logging on these recalcitrant ECM's.
Apologies for resurrecting this old post, but I believe our issue is very similar.
2006 CORVETTE Z06
LS7 - 7.0 LITER SFI V8 - 505 HP
6-SPEED MANUAL TRANSMISSION
We are not certain of the vehicle history, and neither is the owner (recent purchase), but the speedometer is not working.
There is a lot more to the story, but getting to the point - this is where we're at:
We used HP Tuners to save the unknown tune from the vehicle before beginning. We installed a new ECM and while attempting to write the tune we received the 'Invalid VIN/OS Pair' message. We were instructed by email support to update the HP Tuner software to the latest version, but got the same message. After programming the ECM with stock GM Techline programming, we were able to communicate with the vehicle and found that the speedometer works, but the car runs like crap. We wrote the custom tune to the new ECM and it runs fine but the speedo quits working again. We noticed that the Vehicle Speed Output Source is set to RepTOS in the factory tune, but that the same field has no available options in the custom tune. After reading through this thread, we have verified that we have a valid vehicle speed signal to the ECM, but that the data is not making it's way to the cluster and we're wondering if the fact that the Vehicle Speed Output Source field is blank might be the issue.
We're pretty new to the HP Tuner world so we're still finding our way, but if anyone could let us know if they think we're on the right track, we'd sure appreciate it.
Sorry I couldn't provide a log file or config file, as I said we're still figuring this all out.
The tune that operates the speedometer, but doesn't run well, uses the newest OS for that vehicle (2006 Corvette LS7 manual). The tune that runs well, but doesn't operate the speedometer is an older OS (that has been superseded) for the same vehicle.
OS history (newest to oldest):
12614682 (the one you have that operates the speedometer)
12605732
12605196 - replaced the previous OS to address a speed related DIC message
12602922 (the one you have that runs well, but won't operate the speedometer)
Odds are the 12602922 calibration is corrupt.
I would use the newer OS (that operates the speedometer) and simply tune the engine until it operates well.
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