Transmission doesn't recognize proper speed after 0411 swap

I have a 1999 Yukon that I just performed a 411 swap in. I've checked all my wiring and the transmission was working fine with the blackbox PCM just a few weeks ago.

After performing the swap the transmission didn't want to shift properly at all, and I was getting P0715 code. After disabling that code in Engine Diag, the transmission shifted somewhat better, but it still has problems. It's missing shift points, and at times, missing whole gears. I did a test at WOT and 1-2 was fine, it missed gear 3 entirely. There was no drive at all until I came off the throttle and it found gear 3, and it never shifts to OD, at all. I did a test with a GPS up, come to find that the Speedo is wrong, so I redid my calculations for the Speedo. For Trans revolutions per mile, I calculated this:

Tire Circumference: 99.1" (not factory tires)
Final Drive: 3.42
Inches per mile: 63360

63360/99.1 = 639.35418 tire rotations per mile
639.35418 * 3.42 = 2,186.5913 trans rotations per mile.

Now the speedo and GPS agree with each other, but with the scanner plugged in, I can see that the tranny is 16% off @ 50mph. Cruising at 50mph, the vehicle speed, according to the transmission, was 42mph. The transmission speed reading low may account for why it's missing shift points, but I can't see why it would never shift in to OD. I've attached my current file, I've never done a swap like this before and am in a bit over my head. Any help would be appreciated.

Thank you!

So... if GPS on your phone is showing a DIFFERENT speed than your speedo in your dash... I would suspect that you still have the settings in your tune off. You do know that across the top of your Hp Tuners file under the "EDIT" tab there is a "GEAR/TIRE WIZARD" which allows you to simply plug in your tire size and gear ratio, and it will correct all of those other fields for you automatically. Yours shows you have 27.13" tall tires, and 3.42 gears. If that is not correct... I would go back and put back to stock whatever fields you changed, and then update the info in the GEAR/TIRE WIZARD and let it update automatically. Further... The code you have listed is for an INPUT speed sensor.. not an OSS or output speed sensor.. the 2007 and later 4L60/65/70E transmissions have INPUT or TURBINE speed sensors.. but 2006 and older do not. The earlier transmissions 2006 and back do not even have an input/turbine speed sensor at all......

In your transmission shift tables, your full throttle upshift speeds in your upshift tables, do not match those speeds in your FULL THROTTLE upshift tables... that's not to say that your problems lie in the tables.. just that there are problems ALSO in the tables.

You mention going "full throttle" in your post... Please STOP doing that! I can't believe that you are having shift issues and you think it's okay to go out and beat the snot out of your vehicle. So, let me just say it STOP DOING THAT! Until you figure out what is wrong-be it wiring, tune issues, or whatever the issue is-STOP beating on it until you figure that out unless you just want to destroy your transmission.. Maybe you want to kill your current transmission and that is why you are going full throttle while it's not being commanded correctly.

If you do not want to kill your transmission-and I'm on the fence as to what the reality there is-start data logging at LOW RPM and LOW VEHICLE speed using Hp Tuners log, and GEAR COMMANDED as one of your channels-let's see what the PCM is actually commanding the transmission to do... that would be a good place to start. If the transmission is NOT following the commands being sent by the PCM-then you have internal trans issues. If the PCM is sending whacked out signals and the trans is simply following the orders that it is receiving-then that is NOT a trans issue but is something TUNE/PCM/WIRING related. Logging with the correct channels will point you in the right direction. Until you get it sorted-STOP trying to kill your transmission.

I've run into an issue with LS swapping a 90s model truck where the VSS was sending a different pulse than what the ECM was expecting with some setups and between 2wd and 4wd, shifting was all over the place.

This may be of some use to you if the gear/tire wizard is not helping. Note: This intended for a 700r4 which sends a square wave instead of the 4l60e sine wave, so the changes made were probably much more drastic that what you need but hopefully making some small adjustments can get you in the right direction.

https://www.thirdgen.org/forums/elec...l#&gid=1&pid=1

Hope it helps!

Pointing out the fact the I disabled the P0715 code is actually of importance. For some reason, this PCM from 2001 was expecting an input from that speed sensor. And that code being left alive was making the transmission do all kinds of crazy stuff. Disabling it made it much more drivable. Also, yeah... WOT testing in it's state was not a good idea, in my mind it would make it easier to diagnose problems because the table is easier to read and edit, since I didn't have to worry about THROTTLE %....

Thank you for pointing out the GEAR/TIRE WIZARD. After putting in my tire size (30") and final gear ratio, the trans is now shifting perfectly! I set up the GEAR COMMANDED channel in the scanner as well as the THROTTLE % and it followed all the tables perfectly, but that has illuminated a new problem. The tachometer and speedo in the cluster do not read correctly, even after setting the Speedo tab to stock then doing the tire wizard. The speedo is still 16% ahead of the actual vehicle speed and the tachometer is about 20% ahead of actual engine RPM, meanwhile the rest of the vehicle reads the right speed. It makes trouble-shooting a real pain when I don't know how fast the engine is turning or how fast the truck is moving.

Another question about Full Throttle shifting: the way I understand it is when you reach a certain TP% (in my tunes case it's >94%) it enters "Full Throttle" shifting mode and the Part Throttle chart no longer applies. Then when I release the throttle (in my tunes case it's <88%) it goes back to using Part Throttle shifting. If that's the case, does the discrepancy between the part throttle and full throttle tables even matter?

The FULL THROTTLE SHIFT points should match your 100% TPS shift points in your shift tables. It's just a neatness thing. Your tach issues can be resolved by putting in the right #'s in the TACH OUTPUT fields under the ENGINE, GENERAL tab. Try using "3" in both fields.. If that does not work, try "6" in both fields.. video here: https://www.youtube.com/watch?v=FS7aRfYkFAQ&t=607s

Going back to the speed issue.. if you are logging and it is showing the correct speed being reported in the scanner-but your DASH/Speedo is showing a different speed, it's a sure sign the stepper motor (part of the actual speedo) is going bad. Usually the faster you drive, the further off they are. I have a 94 Silverado that I've LS swapped and while I can get the speedo to register correctly at 60MPH and slower, anything above 70 it reads SLOWER than the truck is actually moving.. and gets further off the faster I go. It is NOT a tune issue. It's just that the stepper motor is going bad and I can live with that. Yours may be the same issue. As long as the PCM is seeing the correct vehicle speed, you will be fine.

You are using a 2002 OS which features Transmission and Transmission Diagnostic segments from a 4L80 calibration.

The transmission type has been changed to 4L60 via the dropdown menu.

The gear ratios have also been changed to those of a 4L60.

The above changes achieve absolutely nothing.

You require a proper 4L60 calibration for your conversion project.

good catch shrek! How do you look up the calibration #'s to see what type of trans they tie back to? I see his OS is 9358344 but when I google search it, it shows both 60e and 80e, or turns up a bunch of irrelevant information.That would explain why his INPUT or TURBINE speed sensor was turned on in the tune.

I started to keep a database about 20 years ago, that listed each segment of a calibration by its own individual ID number.

It is by no means an exhaustive source - there are many calibrations missing - but most of the time I will have the segment ID on file.

Quote:

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Originally Posted by HATEHPTUNERS

The FULL THROTTLE SHIFT points should match your 100% TPS shift points in your shift tables. It's just a neatness thing. Your tach issues can be resolved by putting in the right #'s in the TACH OUTPUT fields under the ENGINE, GENERAL tab. Try using "3" in both fields.. If that does not work, try "6" in both fields.. video here: https://www.youtube.com/watch?v=FS7aRfYkFAQ&t=607s

Going back to the speed issue.. if you are logging and it is showing the correct speed being reported in the scanner-but your DASH/Speedo is showing a different speed, it's a sure sign the stepper motor (part of the actual speedo) is going bad. Usually the faster you drive, the further off they are. I have a 94 Silverado that I've LS swapped and while I can get the speedo to register correctly at 60MPH and slower, anything above 70 it reads SLOWER than the truck is actually moving.. and gets further off the faster I go. It is NOT a tune issue. It's just that the stepper motor is going bad and I can live with that. Yours may be the same issue. As long as the PCM is seeing the correct vehicle speed, you will be fine.

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L31s tach signal from the coil. 25% off might be a V6 cluster swapped in place of the V8 one.

Hello guys,
Please I need to adjust the speedometer for my Crown Victoria but I can't find the tab to adjust it, so please help me how to set the exact vss Tire Revs per in the picture.
tire size : 235\55R17
Attachment 125937
Attachment 125938
thank you

461 km

Hi friends, Stopped in to say "Thanks for all the help!!!" The final solution to the speed-o-meter after running the tire gear ratio wizard was an adjustment to PCM Output Calibration, Pulses Per Mile.

In response to SHREK's comment: "You require a proper 4L60 calibration for your conversion project." Can someone direct me to a thread or video on how to change the calibration?

Attachment 126187

Hi Friends, Here is the final solution. This is what I did to fix the issue: Preform a “Segment Swap” watch this video https://youtu.be/k0dF1RQhPo4. I downloaded a stock tune for a 2002 Chevy Blazer 4wd, from the Tune Repository. Preformed the segment swap as described in the above video, I moved the Trans OS and Trans Diagnostics calibrations to my tune. Preformed a “Write Entire”. The truck shifts flawlessly, no more transmission DCTs. I then copied the Performance Shift Timing & Pressure charts into the Normal charts (’99 Yukon doesn’t have a tow or sport mode switch). Trans now has nice quick snappy shifts. Thanks for all the help!!