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  1. B

    T87 Swaps

    That makes more sense. I just got to a point I was a little tired of searches and schematics and decided to plug my hptuners into the t87 and found out that unlike efi, hp actually has all the dtc populated. Otherwise didn’t see anything there that isn’t in efi. So with that at least if we can...
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    T87 Swaps

    That dang squirrel gets me sometimes too. So are you saying that the lmm ecm wants the vss pulses but uses it on a limited basis but uses can vss data? Sorry I think I may have misunderstood what you were saying. I’ve had some time to look at different tunes today and see where with the t43 6...
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    T87 Swaps

    If we can turn on canbus vss on the lmm would that not receive vss from the t87 tcm then since with the duramax calibration in the t87 it is sending out a canbus vss to the ecm? The 15.5 duramax lml has the vss tail shaft sensor connected to the tcm unlike the gas where it goes to the ecm. The...
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    T87 Swaps

    If I recall right the early up through 07 or 08 had an early hybrid type canbus but the 09 for sure had the same can bus as the 07.5-up trucks. Have to look up years but I know that a 2009 Chevy express van has the e38 and new canbus I will do some digging and see what it shows when I bring up...
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    T87 Swaps

    Right because Allison had their own transmission control module and gm had to make it work with their pcm. I think that’s where gm first realized how much more efficient the ocm was when it only had one task and not 2. But aside from that from what I found it seems there could be a very simple...
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    T87 Swaps

    That was exactly what I was seeing. Which pretty much tells you that the replicated speed from the tcm is the same 40 pulse per revolution signal that the sensor is sending. In fact I looked at manual trans ecm tune and it is still set to 40 pulse per revolution on the speedometer table and the...
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    T87 Swaps

    I just dug through any 2010 lmm wiring and pinouts and cant find anything showing the vss on the tailshaft going to anything other than the tcm. There is a vss wire coming from the ecm to the ebcm for traction control use and isnt in the schematics on the non traction control trucks. There is a...
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    T87 Swaps

    seems the old vss sensor is to low of resistance around 1000 hence the low code. that also explains why the closer you could get it to the wheel it would actually start to show something. the lower resistance can generate a better ac field than a dc one. also the new sensors are diode isolated i...
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    T87 Swaps

    on the vss I have pin A to 7 and B to 14. But after playing a bit I noticed it wasnt actually seeing any pulses, just the resistance of the sensor to make it happy something is there, when i spin one of the 40 tooth wheels past it on a drill. So i did even more digging, so on a gas truck the vss...
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    T87 Swaps

    Yep same numbers. If that’s the case then it’s something with the calibration itself and not the tcm itself. I tried used a 2016 vin first and then another 2015.5 and it only gives you a combined programming option but with this vin it allowed only tcm programming. So apparently something in...
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    T87 Swaps

    @kidturbo So today I came across something I found interesting. While at a dealership that I do a lot of work for in northwest ohio, they happenned to have a 2015.5 Sierra 3500 duramax on the lot. I did some looking, the new vss sensor is in fact the bolted in style instead of the threaded in...
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    T87 Swaps

    @kidturbo i actually have a new one coming Monday for a 2018. I wanted it to test against the one in my 2010 to see if there is any variance as well as the new turbine speed sensor.
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    T87 Swaps

    @kidturbo typically wheel speed sensors will range around 3-6 mega ohms because they normally use 2 or more small wound resistors sitting beside the manetic pole to keep them more compact but are more prone to heat fade and damage vs a single winding around the magnetic pole which will normally...
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    T87 Swaps

    @kidturbo after some investigation and looking at parts on the shelf from transfercases and looking up part numbers, I can tell you that 2008-2019 duramax at least all use the same vss reluctor wheel 40 tooth. Even the 2wd models have a 40 tooth reluctor in the tail housing of the transmission...
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    T87 Swaps

    Hey Kidturbo. Sorry was out of town down in florida and wasnt getting notifications for some reason. I just looked up 15-16 both and the wiring is exactly the same. Looks like i have some reading to do here to get caught up on what you have accomplished over the last 2 weeks.
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    T87 Swaps

    I actually have that same BCM sitting on my bench right now that has a blown out diode for the 12v output used for the serial enable. Had a short in the engine harness and guy decided to use a higher amp fuse in place of the 3 amp that kept blowing lol. The one I have is programmed for a 2008...
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    T87 Swaps

    I've noticed doing swaps that the backwards compatibilities aren't there and finding compatible OSs and calibrations can be a challenge. I know the bcm calibrations and os are all compatable from 2007.5-14 lmm and lml doesnt seem to matter they all speak to the ecm and a40-a50-t14 tcms. As for...
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    T87 Swaps

    I have schematics for the t87 pinout as well as all other transmission control schematics for both 2019 tahoe and 2019 duramax l5p. They move the input speed wire from 12 to 15 between the 2 as well as a few other differences that could cause some of the speed sense issue. Also I read your...
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