Stan - how do you set the TPS value in a SG2 with XGAUGE? i checked the manual and i couldnt find it...

 

nyceshirtz — That's because it's apparently not in the Manual (yet)! Somewhere in one of the screens (search through them!) there's a new ability to set a value for the TPS reading below which the "new" ScanGauge will assume that, if the ICE is running open-loop, it's not either warming up or operating at wide-open throttle, but is actually spinning in fuel-cut mode (spun by MG1). I've been watching my "old" SG's TPS readings when starting my TCH at various low (below freezing) temperatures this winter, and I find that a TPS setting of '16' will correctly separate the open-loop-fuel-cut-with-ICE-spinning case from the open-loop-using-fuel-with-ICE-spinning case. Then the fuel usage should (correctly) read zero during fuel-cut operation, and the SG's computation of fuel usage should then be correctly handling fuel-cut operation. Prior to this, the fuel usage registered by SG was always greater than or equal to the TCH's correct figure, since it incorrectly thought that fuel was being used during fuel-cut. According to Ron DeLong at Linear-Logic (the SG manufacturer) this is because the Toyota hybrids apparently still put out a fuel injector pulse signal even during fuel-cut, although the injectors themselves are not actually injecting fuel during this time — there's a separate "fuel-cut" signal being passed by the ECU, but SG can't conveniently access this other signal.

Stan

 

stan - the setting for TPS can be found under SETUP/FUEL/CUTTOFF. However, I set the cutoff between 13, 14, 15 and 16 and it still didn't displaythe mpg properly. I spoke with Ron of ScanGauge who said that the setting should be higher than the TPS observed when in EV(Open Loop) mode. I observed that when MPH is less than 39MPH and in EV mode(Open Loop and coolant temperature greater than 154 degrees farenheit) the TPS initially drops to 13, then varies between 14 and 16. In addition, the GPH indicated while in EV mode displays .02 through .04 GPH, while RPM remains constant at 0 and MPG varies as GPH and MPH change, but seldom displays a MPG of 9999, which is what it should display in EV mode. I will set it at 17 and see if that helps the calculations.

 

nyceshirtz — Thanks for the information on the SG's new "CUTOFF" setting. I have been monitoring the behavior of my TPS reading all winter, and have found that, when the car is open-loop and burning fuel (e.g., during the first few seconds of warmup after starting cold) the TPS is always above '16'. Thus, a CUTOFF setting of '16' should separate the open-loop-and-not-burning-fuel (i.e., fuel-cut) case from the open-loop-and-burning-fuel (i.e., warmup, wide-open-throttle, etc.) cases. If your fuel-usage continues to be nonzero when the car is in fuel-cut, it would seem that Ron hasn't fully implemented the nulling of the readouts under these conditions. Try the metric readouts too (set units to km and L) — they may behave differently. Let us know!

Stan

 

stan - no difference`with TPS at 17. Same result as my previous post. When I last spoke to Ron, he stated that he would have to update the calculation so that when the TPS is equal to or less than the cutoff value and the GPH value is 0.04 or less, he would have to zero out the GPH value in order to arrive at the desired MPG amount of 9999. Ron also stated that would be forthcoming in the next update.

 

nyceshirtz — Thanks for the information from Ron! This is really frustrating, since I discussed all this (about zeroing the fuel usage, etc.) in lengthy e-mails with him a long time ago. So why wasn't it implemented? One reason that I haven't yet had my SG updated is that I'd prefer not to have to send it in a second or third time! I'll wait until the code seems to have settled down before sending it in.

Stan