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HPTuners disabled my speedometer!

ms38w

Full Member
Joined
Oct 12, 2007
Messages
4,169
Location
Bent Mountain, Virginia
  Anyone heard from Flabouy lately...he seems to be pretty knowledgeable about HPTuners.

  Anyway; I was messing around with my tune files, making some changes to the setup on  my Av, and wanted to use a tune that previously didn't suit my needs.  I figured, what better way to learn HPTuners than to tinker around with a tune that needed adjustments anyway?  So I loaded in the tune file and the ABS & Parking break lights on the dash came on and stayed on...and when I took it for a test run, the speedo never moved...no wonder the ABS light is on  :p  .  So I opened up the file and looked at the parameters, and I don't see anything that would make the speedo not work.  This has happened to me before with various tunes, trying to find the "sweet spot" in the motor.  In the past, it has always corrected itself when I loaded in another tune, so the tune itself had a flaw in the speedo parameters.  I get it.  Just compare the current tune with the speedo malfunction to a previous tune with a good speedo, and make the necessary changes...wrong...didn't do the trick.  So I put the previous tune back in and the speedo still doesn't work.  Aside from looking through dozens of failed tunes to get the speedo to work, and the motor NOT work, how do I fix this.  Where are the HPTuners gurus that can tell me where to look in my HPTuners to make my speedo register again?

Thanks
 
Personally based upon my working with HPTuners and trolling their forum on a daily basis, I would never recommend loading in someone else?s tune into your truck. Always modify your tune instead. 

What happens when you compare your stock (or previously working tune) to the one that you loaded into the truck?  Use the compare feature to list what is different between the two tunes (CTRL-5).  I would also use the latest version of HPT.  Post your tune, I take a look. 
 
Yeah, it's not someone else's tune, it's a tune I paid Nelson for but didn't suit my need at the time.  I forgot about the compare feature.  I'll send you a copy of the tune file, thanks for looking at it.  I'm just learning my way around HPTuners, tinkering with some tunes here and there to see what I can accomplish. I accidentally hit "save" instead of "save as", so if I inadvertently changed something I shouldn't have, it's in there now  :E: .
 
So go back to the tune just previous to the one you possibly just overwrote. Or go back to Nelson and ask them to resend the last calibration file they sent to you.

I agree with Silverghost; one of the things I do is lots of looking around in different tunes with the compare feature prior to modifying my current tune. And I do a ton of research on the HPT forum and PT.net on the feature I want to modify. Then I make multiple small changes, logging between changes, so that I know that I'm not causing any issues.
 
ms38w said:
I accidentally hit "save" instead of "save as", so if I inadvertently changed something I shouldn't have, it's in there now  .
  Which eliminates the possibility of just putting the previous tune in...I was tinkering with it, and saved it instead of save as. I didn't catch it until I tried to go back and use it.

I don't know that Nelson has saved a copy of tunes he has sent to me...there are so many, he likely wouldn't know which one to resend if he does have it.  It's not the last tune he sent, either...just a better tune that I've been using.  Actually, the tune that is in question is a more recent tune that had some issues, the biggest change was the engine size. He had the cylinder volume set to that of the 5.3L, but mine is a 6.7L so I corrected to reflect that, and it has taken care of the "stumble" at 2500 RPM. I also changed the tire size and corrected for the rear gear.  I was looking at the rest of the file as well, and must have changed something and didn't realize it.  I did a "compare", and it only shows a difference in "mile" field...but when I look at the 2 files, there is no difference in the "mile" field. Not sure why it is telling me they are different. they both say 97277, and the "compare" says -97277 and all other fields show "0's". That would tell me that one file has 97277 and the other 0, which would mean that that one is 97277 below the other...right?
 
ms38w said:
  Which eliminates the possibility of just putting the previous tune in...I was tinkering with it, and saved it instead of save as. I didn't catch it until I tried to go back and use it.

I don't know that Nelson has saved a copy of tunes he has sent to me...there are so many, he likely wouldn't know which one to resend if he does have it.  It's not the last tune he sent, either...just a better tune that I've been using.  Actually, the tune that is in question is a more recent tune that had some issues, the biggest change was the engine size. He had the cylinder volume set to that of the 5.3L, but mine is a 6.7L so I corrected to reflect that, and it has taken care of the "stumble" at 2500 RPM. I also changed the tire size and corrected for the rear gear.  I was looking at the rest of the file as well, and must have changed something and didn't realize it.  I did a "compare", and it only shows a difference in "mile" field...but when I look at the 2 files, there is no difference in the "mile" field. Not sure why it is telling me they are different. they both say 97277, and the "compare" says -97277 and all other fields show "0's". That would tell me that one file has 97277 and the other 0, which would mean that that one is 97277 below the other...right?

I caught that note in the first post.

But you really should always be doing a "save as" each time you change the configuration file so that you have a history of changes made. For instance, I chose to use the date each time I save and flash a configuration. Others simply use an "index" number....the first tune starts out as "ms38w001", the next "ms38w002", etc. I have every change I've ever made, in addition to the original stock file, and the original Diablosport base tune for the Magnacharger.

I can almost guarantee you that Nelson has all the configuration files he has sent you, though you indicate you did some tweaks. If you know what you did, and it appears from your response that you do, he could send you the file you made the tweaks on and re-do them. But, you would have to know which config file you tweaked, and it appears you likely don't. It's not a bad idea to save all of the Nelson email files in a permanent folder, which I have also done.

What you are saying about the speedometer appears to be correct regarding the compare of the two files but obviously something is being overlooked somewhere and it's very difficult to diagnose it remote. I'd take a look if you sent me both config files that you are comparing but I couldn't help with changing it and returning it, unless you've got the latest beta version of HPT.

If nothing else you send a copy of this config file to Nelson, explain the symptoms as in this thread, and ask him to take a look at it and fix it. Retunes are supposed to be free.
 
Yeah, I have many tunes from Allen...trying to get the truck to run right.  The only problem is it is a slow process, sometimes not hearing back from him for several months.  The original tune is probably 3 years old by now, and it has been difficult to get it just right.  I have saved all the tunes he sent, many of which are quite rough...some don't even allow the truck to start.  I guess I'll have to go through them until I see a difference that would effect whether the speedo works or not and see what is different.  Evidently, the tune I put in the other day was one of the ones that disabled the speedo.  This was a Nelson tune as well, as are all my tunes, so it was sent to me with the speedo disabled...don't know why.  That is likely the reason I didn't use it when it was sent.
 
Well, I've put several past tunes in, just to see if the speedo would start working again, but no luck.  I even found the tune Nelson sent me in my email...so I installed the unmolested file, but still no luck. Maybe there is actually a problem with the speedo. I had left the HPT MPVI interface plugged in the other day, and didn't think anything of it.  I then installed the tune and when it came time to start the vehicle, it wouldn't fire...,just a "R,R,R,R"...so the MPVI interface must have drained the battery.  Could I have blown a fuse?  Does the speedo have it's own fuse?  Everything else on the dash works.  Also, it was odd that the "tow/haul" light came on.  I didn't think it to be a problem.  After tinkering around trying to get the speedo back, the "tow/haul" went out. It might also be that the shop that did the state inspection sabotaged me...they probably weren't too happy that I did  my own repairs instead of paying them $700.  I actually had a Ford dealership sabotage me once...like they didn't get enough money from me with the repairs they made...they unplugged a headlight and tucked the harness in behind, coiled up nice and neat...baristas!
 
under edit there is view change/history logs it will tell you what the setting was before and what you changed it to
 
Have you tried to see what the HPT scanner can read?  Does it read MPH?  If it does then that would make me think maybe the speedo has a bad connection or went bad.  If you have a 6.7l then at some point a new harness connection was involved.  ???

 
  Well, this time I may have to discount that it is HPTuners.  I have put several past tunes in, trying to find one that will re-enable the speedometer, but to no avail.  I just find it strange that it went out with a newly installed tune...instantly.  It didn't even work for a moment.  I could see if it was fine and then after driving around it quit, I would not blame the tune...but as soon as I turned the key on, I saw something was wrong...ABS light on, Parking break light on, tow/haul light on.  I drove it anyway to check engine performance, that's when I discovered the speedo wasn't working.  I will have to hook it up and take a data log file tomorrow (gotta get ready for work now).  So, if HPTuners records a speed, but the speedo doesn't read...where do I go from there?  Stepper motor?  Does the speedo have its own fuse?  I didn't see one under the hood or in the panel on the side of the dash.  I didn't look under the dash by the pedals, only because i think those are all related to breaks/trailer wiring.  Am I wrong?  Could it be that there is actually a problem with the ABS, causing the speed to stop working?  I recently unplugged the driver's side ABS harness to change the upper control arm, but all appears in tact and plugged in tightly.
 
Maybe try disconnecting the battery to reset the computer since you said it was dead when this started, it might have messed something up.
 
Yeah, I disconnected it over night, but still not working.  I have been looking for stepper motors on ebay and amazon, but nothing is listed for an '02 chevy truck of any kind.  Does the '02 not use a stepper motor?
 
  Well, it may have been a case of sabotage.  I jacked the truck up again and  crawled under it.  I wanted to make sure all the connections to the ABS and to the transmission were tight.  The cable that runs into  the transmission was loose...imagine that.  I don't know if it was intentional, or the guy at the shop doing the inspection was "curious" about all the mods to my truck and started poking and tugging on things to see where they went.  It wouldn't be the first time someone has intentionally messed something up to make a buck, but I couldn't swear that was the case.  It must have taken a few miles to come loose enough to not make the connection.  Still, strange that the speedo stopped when I installed a tune.
 
I'm not sure how permanent the fix was.  Shouldn't there be a boot or shield of some sort where the speedo cable enters the transmission?  Mine has a hole about the size of a golf ball with a cable about the size of my finger going into it.  I can't see inside the hole very well because my angle is all wrong.  Maybe if I could get it up on a lift and stand under it I could see inside better, but laying on the garage floor with a light isn't doing the trick.  I don't know if putting the Av up on a lift would help either with the driveshafts, T-case, exhaust, etc. in the way and the speedo cable enters the transmission towards the top.  I fear dirt, small rocks and water might get into the transmission through this hole.  I could be wrong...maybe nothing is exposed within this hole.  Anyone know?  I  made a makeshift boot out of a protective cover that came on my tie rod in the mail.  I siliconed it into place, but couldn't get in there too well to make sure it is sealed.  It might not matter.
 
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