Just installed the Smart Tune Pro, and would like to ask those with more experience with it for some clarification.

It seems to me that the STP doesn't actually communicate with the ECM like the Pro Street Tuner or PowerVision do. There are 5 cables on the STP: a ground cable, 2 wide-band O2 sensor inputs, and 2 narrow-band sensor outputs which go to the ECM's narrow-band inputs. There's no connection to the ECM through the diagnostic connector at all.

I was originally wondering why there was a ground cable but no power cable. Then I assumed the unit draws power from the ECM for operating the O2 sensors, so it may siphon off some of that for its own operational needs. Don't see how that requires a separate thick grounding wire, but that's irrelevant.

The thing is, I can't see how this unit could do anything other than translate wide-band sensor input into narrow-band output (which makes little sense) or, perhaps, it outputs the wide-band input as a digital signal and the ECM'S Smart Tune-aware calibration teaches the ECM to read the O2 sensor input as a digital signal instead of a simple analog voltage reading?

And if that's the case... Then the STP unit does no corrections or adjustments itself, at all. In this case it seems that it is a small part of a larger Smart Tune Pro Ecosystem, where:
A) the Pro Street Tuner does all the "tuning" by loading the STP-enabled calibration. This calibration allows for full ECM control of the entire fuel map, extending Closed Loop operation across the whole map.

B) the ECM does all adjustments like it always did, with two main differences: Closed Loop is extended across the whole map, and the adjustment range it's allowed to do is expanded to around 30-40%, from the stock 10%-ish?

C) the STP translates wide-band sensor output into a signal that can be effectively communicated into the ECM's narrow-band inputs.

This seems to be the only way this can work, and it does sound like it could work well for what it is. But: this also means that the STP cannot update the VE tables continuously, since only the tuner can update those. So if you're not doing "auto tune sessions" and applying those in the HD software and then reflashing the ECM, then ... does that mean that all the "learning" the ECM does is lost when you shut the bike down? And has to be re-learned next time you ride?

This theory of the STP device acting as a simple signal translator also explains why it can be used with the PowerVision (which is how I will be using it). DynoJet's Target Tune does connect to the diagnostic port, so potentially it could communicate with the ECM, but if it does, then how does the PV work with the STP, which can't?

Sorry for the encyclopedic post; just trying to wrap my brain around how this thing works. Thanks in advance for any clarification.

 

I read what you posted and asked. Went and did some research. Yup.
The Smart Tune Pro STP auto tunes only based on the 02 sensors and with the wide band, better readings. Constantly sends signal to tuner, in conjunction with ECM.
Seems that you have to have a tuner in place FIRST before adding the autotuner. Smooths out the 02 readings and sends to tuner - ECM.

If you have a SE tuner, adding the STP does benefit. IMHO
Good Day~

 

Tuner/Tune limitations still exist. Using the "W" version of the appropriate SE map allows the system to recognize/use the wide band sensors in place of the narrow band sensors (different voltage signal).
The SE maps still have the +/- range limitation, whether using the NB or WB sensors- 4 points in the closed loop area, 10 points in the open loop area, keeping the map within the EPA/CARB certification levels.
BTW, 10 points = ~0.5AFR (1/2)
WB range


NB range

 

The Auto Tune module doesn't change the tune that a Tuner puts into the ECM, it just maintains the fuel clipping asked for by the tune taking into account weather changes (altitude, barometric pressure, humidity).

 

Yes, that all sounds like what I was presuming; thanks for the confirmation.

While I do have an old SEPST here somewhere, I don't plan on using it. I'm using the PowerVision, and have a wideband-enabled tune from FuelMoto. I'm thinking that the STP module likely doesn't have any restriction on it (as a simple signal translator); since the restrictions are built into the SEPST, so when you load an EPA-compliant tune into the ECM the tuner sets the limited adjustment range to keep all results EPA-compliant. But when using the PowerVision it unlocks the ECM and allows the full range of adjustment. And since (I assume) the STP is a signal translator and not a tuning device, I am assuming it passes the full range of wideband readings into the ECM and therefore there's no EPA compromise happening with a PV/STP combo. At least, in Jamie from FuelMoto's articles and videos on using the STP with the PV, he never mentioned any restriction as compared to DynoJet's own Target Tune.

Other assumptions: since the tuner (whether SEPST or PV) is the only device that can change the ECM's tune/calibration, once the tune is loaded in the ECM, that explains why the tuner becomes an irrelevant part of the process and can be removed and the "autotuning" process still proceeds -- because it was never "tuning" in the first place, it's just adjusting fuel trims like it always did. Which explains why a highly accurate tune/calibration is so important. Which means that running a few wideband-enabled "autotune" sessions would still be a very good idea, even with the "autotuner" installed. That way the calibration inside the ECM would be as accurate as it can be so minimal adjusting should be necessary (and minimal re-learning should be necessary).

 

The Smart Tune Pro is no different than any of the DynoJet products. The Wide Band information is sent into the ECM and it gets used. "Autotuning" is nothing more than a Internet salesman's BS, as NONE of them auto tune anything. One needs to understand that the ECM is in control and it's as dumb or smart as the person programming it. So it doesn't matter if you use Target Tune or Smart tune. As for using them to properly tune an engine, it's a pipe dream. Look, what they are OK for is to keep a properly tune bike trimmed in on the fuel adjustment side only! It will never set the proper fuel mixture, set the timing, correct the EGR, calibrate the sensors or any of the things that must be done to tune an engine.

"But when using the PowerVision it unlocks the ECM and allows the full range of adjustment"

This is yet again another Pipe Dream as it doesn't even come close. What it does is expose only some of the information and allow for it to be adjusted, there is still tons of things it doesn't allow. Yes, it gives more range of adjustment than the SE Pro Street Tuner but do not believe for one minute it gives full range of adjustments because if it did there would be no reason to have to readjust the engine size or injector size to anything other than the actual size, of the engine being tuned.

 

That's kind of what I was getting at -- the Smart Tune Pro doesn't tune anything, it just gives wideband sensor data to the ECM, and the ECM proceeds with its same adjustments as it always has, except now it can do so across the full map instead of working only within a smaller "Closed Loop" area. So in essence it's the entire map that's closed loop. And, the ECM doesn't tune anything, it just tries to get the AFR to match what the given calibration is. So it's all still dependent on the user to set up a proper calibration, ideally through a full dyno tune. Interestingly, DynoJet basically says exactly that in the instructions for the Target Tune:
I think you misunderstood what I was saying there. In the lead-in sentence I said that the Harley tuner was limited by EPA regulations, which then led into saying the PowerVision removes that restriction and allows the ECM to make its adjustments without EPA limits. I did not mean to imply that the ECM was somehow a fully-unleashed tuner with all new capabilities!

In my understanding the ECM is the same ECM it was before STP or TT were added, and it runs its routines the same way that it always has, there's no new magic capability. There's just a change in the range of adjustment it's allowed, from the +/- 10% (or whatever it is) of the stock ECM to somewhere around +/- 30-40% with the STP/TT-enabled calibration. I base that statement on Dynojet's FAQ where it says:
What I was trying to get at is that far from becoming a replacement for an experienced dyno tune operator, the STP just gives the ECM the ability to control the previously-off-limits Open Loop area of the map, and that it can now read wide-band sensor data instead of narrow-band.

Which is trying to verify another data point: I believe the STP is likely not EPA-restricted in and of itself, since that seems completely unnecessary; the SEPST is where the EPA restriction exists, even if the STP supplies it the full 10:1 to 20:1 AFR range that a wideband sensor can report. Is that assumption accurate? Or is there any reason to believe that the STP is artificially restricting the range of AFRs it reports?

 

Upon a little further digging, it appears that my initial assessment was largely correct but incomplete. The $600 Smart Tune Pro is in no way a tuner or anything else, it is a simple O2 Control Module (which is exactly what it says it is on the sticker on the product):



As everyone but me probably already knew, an O2 Control Module's job is to enable and control the operation of O2 sensors, which apparently need a fancy controller to do their job. Taken from an article on the Haltech support page:
So, yeah, that's it. There's nothing remotely related to "tuning" being done by the Smart Tune Pro device. It's just an oxygen sensor controller, and a couple of O2 sensors. That's it. All the marketing about "automatically tuning your bike" is not being done by this product! Installing the STP just adds wideband sensors to your bike. You still need to tune it with a tuner to get as accurate a calibration in the ECM as you can. After that, any "autotuning" that gets done is done by the same ECM in the same way it always has been done, but now (because of your tuner) the ECM is able to adjust on a wider range of AFRs, and it can adjust in the previously off-limits Open Loop area of the map. So what they're attributing to this product is in fact more accurately attributed to the larger "Smart Tune Pro" ecosystem, which requires the ECM, the tuner, a wideband-enabled calibration/tune, and finally this last piece, the O2 controller and wideband O2 sensors.

This makes a hell of a lot more sense now. Just reading the description on the Harley site gives you a very different idea of what this module does. Thanks for helping me wrap my head around this.

 

Just remember that NONE of the Wide Band units are capable of changing the ECM, and as a matter of fact the ECM does NOT remember any of the WideBand adjustments, it treats them just as it does the original Narrow Band sensors. So it can learn only in the Closed Loop area, it cannot learn in the Open Loop area at all.

 

That's basically what I was expecting, except the notion that it can only learn in the Closed Loop area.

I expected that the only way that the ECM gets changed is if you do a Smart Tune or Auto Tune session on your tuner, recording data, then merging the maps and re-writing to the ECM. Since the tuner is the only device that actually communicates with the ECM, that surely had to be the only way to refine the tune closer to optimal, without having to start over from scratch.

But surely that recording session applies to the Open Loop area as well? When you're running a Target Tune-enabled or Smart Tune-enabled calibration?