Dakota digital SBI-100BT help anyone?

marty79

marty79

the LS Swap Guy
Joined
Nov 24, 2013
Location
Conover, NC
anyone have experience with this unit..my first time having to use one.
its wired in, works but speed reading/ output is off therefore my shift points are off.
08 5.3 4L60 into 88 Grand wagoneer with original np229.
I just need help how to calibrate it from here and the instruction manual isn't much help cause when I read it its just too complicated.
(Dakota digital tech guy got me this far but was hoping to get this fixed/adjusted Sunday to really test drive it)
thank you very much
this is the unit
SGI-100BT_128K OUT from 8k L-H.png
 
Once you wrap your head around what you are doing it should not be too bad. I put in an SGI-5C (grandfather to your unit) in my Nissan a decade ago to do the speedo correction but I was simply converting at the same pulse rate.

Looks like the NP229 has a 13 tooth drive gear. You need to know what tooth count the driven gear is to get the gear ratio for the speedo gears. I am going to guess it has a white 27 tooth gear for the stock Wagoneer tire (235/75R15) and 2.73:1 axle gears it came with. That means the output shaft rotates 2.07 times for every rotation of the speedo gear (27/13).

A 235/75R15 is 28.9" tall and has a circumference of 90.72" and rotates 698.4 rotations per mile. Multiplying by the axle ratio nets 1906.7 transfer case output shaft rotations per mile. Dividing that number by 2.07 nets 921.1 speedometer cable rotations per mile.

The Dakota digital 8k VSS is 8 pulses per revolution.

So if you are trying to use a 8k ppm vss that has mechanically connected to the speedometer cable with the above example you have to divide 1000/921.1 to get the calibration factor of 1.086 because the VSS is turning somewhat slower than 8k pulses for every mile.

If the vehicle does not have stock tires or axle gears you then have to adjust for both. If I guessed the wrong gear on the speedo you have to adjust for that. They are color coded within gear ranges, without pulling it you would not know what it is but it will change the math. You can follow my work above for different gears and tires.
 
awesome thank you for your help.
the jeep has 31x10.50 tires, 2:73 axles
everything is hooked up and driving shifting "mostly good"
but it wont downshift when cruising and you give it part/half/wot throttle! Also shifts out of first super early (expected on 1-2 shift because of the lag in the vss generator according to Dakota people)
Called Dakota digital and they now tell me the SGI-100BT wont really work for my application of "trans controller " (yet they sold me these products) and now telling me to buy a rear axle 40tooth reluctor ring kit..kinda ticked off so I'm hunting around on forums to see if anyone has tricked this sgi-100bt unit to work "good enough "...
my tuner has updated the tire size and gears in the ECU but not the separate TCM yet...planning on seeing him Monday
 
and I have adjusted the sgi-100bt while driving it to where the speed reading from the sensor is matching the speedometer and GPS using my scantool to see the computer live mph reading..that hasn't helped with downshift issues
 
I cannot help you with the downshift issue; I only own one automatic and it is stock. I thought this generation uses a unified PCM that handles the engine and transmission with one computer. Vortec 4.8/5.3/6.0 Wiring Harness Info
 
OnlyOneDR said:
I cannot help you with the downshift issue; I only own one automatic and it is stock. I thought this generation uses a unified PCM that handles the engine and transmission with one computer. Vortec 4.8/5.3/6.0 Wiring Harness Info
Click to expand...
no worries buddy thank you for your help.
and the Gen 4 and 5 LS/ LT motors have separate TCM unfortunately
 
I'd have put a GM NP241 in it with an SYE in it from the start. It would have likely been easier, faster, and probably cheaper in the long run.

Also, JagsThatRun has some good stuff. Check them out if you haven't.

jagsthatrun.com

Speed Sensors

Why You Might Want One. Without a Vehicle Speed Sensor (VSS) and the reluctor ring that feeds it signals, many engines including the Chevrolet TPI fuel-injected engines we specialize in will not run correctly and will not pass a smog test.Background on Our VSS Products. JTR Stealth Conversions...
jagsthatrun.com jagsthatrun.com
 
Last edited:
Croatan_Kid said:
I'd have put a GM NP241 in it with an SYE in it from the start. It would have likely been easier, faster, and probably cheaper in the long run.

Also, JagsThatRun has some good stuff. Check them out if you haven't.

jagsthatrun.com

Speed Sensors

Why You Might Want One. Without a Vehicle Speed Sensor (VSS) and the reluctor ring that feeds it signals, many engines including the Chevrolet TPI fuel-injected engines we specialize in will not run correctly and will not pass a smog test.Background on Our VSS Products. JTR Stealth Conversions...
jagsthatrun.com jagsthatrun.com
Click to expand...
that's what I've done on every other swap but hes had the np229 rebuilt already and works perfectly so we kept it..every swap has its issue lol (part of these jobs)
my tuning guy can get it working next week from HP tuners forums but hes not gonna like me lol
 
OnlyOneDR said:
I cannot help you with the downshift issue; I only own one automatic and it is stock. I thought this generation uses a unified PCM that handles the engine and transmission with one computer. Vortec 4.8/5.3/6.0 Wiring Harness Info
Click to expand...
since you seem to really understand this stuff, thought I'd see if you understand why this is working.
I played around with the wiring on this sgi-100bt and did this Output 1 as some suggest and it works meaning trans winds out in the gears, it downshifts when cruising BUT 1-2 shift is super hard and no overdrive...I feel like I'm close but not there yet ...on the right track but according to Dakota digital schematic running the output wire from OUT 1 doesn't make sense to me when it should be coming out of OUT 3 where the 8000ppm is multiplied x4 to 128k which is what LS transmissions/ECU want
SGI-100BT_128K OUT from 8k L-H.png
 
I did some reading to understand your application better. There are two wires and a ground to the TCM from the VSS. I assume you are using the signal out to the signal input on the TCM. Did you connect the other signal wire to SPD- along with the new VSS wire? Without it you are open-circuited. Dakota Digital's diagrams do not really show this. I am using this diagram as a reference for the 08 transmission wiring: https://www.lt1swap.com/pictures/4L60E Shift Controls.gif

Another question, was that engine and transmission from a car or truck? I read that gen iv cars have 4k ppm and trucks are 128k ppm. And unlike gen III that is not configurable with a tuner. That may be why an 8k signal is kind of working, if it is a car computer it is getting pulses too quickly with it set up for 128k but 8k is not nearly as far out. Try OUT3 and set the unit for L-L which would slow the pulses by half from an 8k sensor.
 
OnlyOneDR said:
There are two wires and a ground to the TCM from the VSS.
Click to expand...
theres only 2 on this Truck harness..a High and Low.
I have it wired a "Ground" from the pulse generator going to SPD- and the Signal wire going to SPD Input as Dakota tech told me.
then there 1wire coming out of the Sgi-100bt going to High side/wire of stock LS harness that would've normally gone to VSS on Tcase.
I tried Out 3 and that's where takes off in mostly 2nd, will shift smoothly all through the gears and into OD but No Downshifts
I tried Out 4 no difference
then I tried Out1 and that's where I'm at..starts in 1st, really hard 1-2 shift..rest are smooth but no OD and downshifts perfectly (very responsive).I only drove it once like current setup since that 1-2 hard shift made me nervous
(Dakota tech said no wire needs to go to Low side of stock VSS wiring harness so that is left open or blocked off).
 
btw @OnlyOneDR i am so grateful for your time in helping me and am more than happy to pay you for your time/research in helping with this. very kind and awesome of you!🤝🙏
 
btw, I'm using a Sen-01-4160 pass thru generator that provides 8000ppm VSS signal since the np229 doesn't have one
 
marty79 said:
theres only 2 on this Truck harness..a High and Low.
I have it wired a "Ground" from the pulse generator going to SPD- and the Signal wire going to SPD Input as Dakota tech told me.
then there 1wire coming out of the Sgi-100bt going to High side/wire of stock LS harness that would've normally gone to VSS on Tcase.
I tried Out 3 and that's where takes off in mostly 2nd, will shift smoothly all through the gears and into OD but No Downshifts
I tried Out 4 no difference
then I tried Out1 and that's where I'm at..starts in 1st, really hard 1-2 shift..rest are smooth but no OD and downshifts perfectly (very responsive).I only drove it once like current setup since that 1-2 hard shift made me nervous
(Dakota tech said no wire needs to go to Low side of stock VSS wiring harness so that is left open or blocked off).
Click to expand...

I see it now, had the wrong sensor (I was looking at ISS, not VSS).

Here is the wiring for yours: https://lt1swap.com/pictures/4L60E PNP Signals, VSS Signal and Tow-Haul Signal.gif

I think you need to take that low reference from the factory harness and connect it to SPD- in parallel with the VSS input from the DD sensor. Otherwise there could be variation of reference voltage due to different grounding paths.

You did not say, is the ECM/TCM from a truck or car? Do you know the donor vehicle?

*edited to add* In the future you could look at using a mechanical speedometer splitter and the Dakota Digital 128k GM VSS. That would allow the owner to keep the mechanical speedo but provide a second mechanical output to drive a 128k TCM/ECU. Something like this: Dual Drive Ratio Adapter - Straight Through Plus this: 128k High Frequency GM Pulse Generator but without having to do all this signal conversion.
 
OnlyOneDR said:
you need to take that low reference from the factory harness and connect it to SPD- in parallel with the VSS input from the DD sensor.
Click to expand...
connect it to input or to the SPD- where the other ground is going to from the DD sensor?

OnlyOneDR said:
You did not say, is the ECM/TCM from a truck or car? Do you know the donor vehicle?
Click to expand...
sorry, it's a 08 Chevy truck 5.3/4l60e stock harness, np229 tcase.
E38 ECU T42 tcu.
man thank you so much
 
Both the DD VSS wire and the Low Reference VSS from the harness will connect into SPD- (two wires in the same terminal). The other DD VSS wire goes to Input, the Harness High VSS to OutX.
 
OnlyOneDR said:
Both the DD VSS wire and the Low Reference VSS from the harness will connect into SPD- (two wires in the same terminal). The other DD VSS wire goes to Input, the Harness High VSS to OutX.
Click to expand...
awesome will do that and report changes. itll be probably tomorrow cause I've got insulation everywhere that I'm installing today. thank you so much again!
 
a little info my tuning guy just called me to say the E38 ECU is looking for 40000ppm from vss sensor if that helps in any way. He's not familiar with this Dakota Digital product but he's heard of it and he's not fond of it so he's not able to really help me haha.
 
Well I guess it's off to the tuning guy I tried what you said today it wouldn't shift at all on Out1, so then I put it back to Out3 had to leave it there for now to shift at all..
spoke to Dakota Digital Tech he told me he's out of ideas other than go to my tuner and see hopefully he can get it all to jive together unless you have any other bright ideas it looks like this module is doing what it can for now.
The tech from Dakota Digital said it shouldn't have ever even shifted in Out1 when I did that on Friday because of what it puts out which is only 8,000 and LS ECU and TCMS require 128k so he doesn't understand how it was working even if it was only momentarily so I don't know he's not being a whole lot of help since it's their module and they can't figure it out lol.
 
So in all the reading I did I learned that the reluctor ring on a stock GM transmission connected to a modern LS has 40 teeth aligning with those aftermarket kits. That does not equate to 40k ppm, however. Your average tire is about 660-700 rotations per mile (call it 680) and multiplied through an average axle ratio of about a 3.2 nets you about 87k pulses per mile. (680 x 3.2 x 40). It would then take a calibration factor of ~1.5 to get the 128k ppm, less for a higher axle ratio, more for a lower axle ratio.

Did you ever pull the speedo housing to confirm the tooth count on the speedo driven gear? I was guessing it was a white 27 tooth.

Did your tuner ever look into the pulses per revolution programed in the TCM? I am wondering if it is not set for 40. That 2.73:1 is also well below any stock ratio on a late model GM so it could be confusing things?
 
OnlyOneDR said:
So in all the reading I did I learned that the reluctor ring on a stock GM transmission connected to a modern LS has 40 teeth aligning with those aftermarket kits. That does not equate to 40k ppm, however. Your average tire is about 660-700 rotations per mile (call it 680) and multiplied through an average axle ratio of about a 3.2 nets you about 87k pulses per mile. (680 x 3.2 x 40). It would then take a calibration factor of ~1.5 to get the 128k ppm, less for a higher axle ratio, more for a lower axle ratio.

Did you ever pull the speedo housing to confirm the tooth count on the speedo driven gear? I was guessing it was a white 27 tooth.

Did your tuner ever look into the pulses per revolution programed in the TCM? I am wondering if it is not set for 40. That 2.73:1 is also well below any stock ratio on a late model GM so it could be confusing things?
Click to expand...
oh man we tried tuning it today, tried everything, messed with ppm values, ppr values, gears tires stock 2wd tunes..over 3hrs of trying and NOTHING was working or having no affect on the transmission.
I'll double check speedo gear tomorrow sometime
 
See post #7 :D
 
OnlyOneDR said:
Well that means you at least know the speedometer cable runs exactly half the output shaft speed.
Click to expand...
so what does that mean for the signal that the PPM generator is putting out? would it still be 8000ppm like DD says it puts out or is that dependent on this 26tooth gear...
Posted from another forum I'm getting help from:
""TCM must get accurate OSS signal. And the first thing you have to do is adjust pulse converter so that OSS will be accurate.
Place trans in 3rd gear and compare ISS and OSS, they must be the same, not 1% accurate, not 0.2% accurate, exactly the same.
If you know Transfer Case speedo cable gear ratio use calculated coeffs for pulse converter rather than measured error.""

What is he talking about "calculated coeffs"?? I'm trying to understand stuff so I can have a plan of action for Monday with the tuner so bare with me, thank you
 
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