Re: Open Loop / Closed Loop Question
I think the answer may be in how other HSD drives work. I know much more about the Prius than the Camry and although the two are totally and completely different in practically every way, there are a few key similarities. One of these seem to effect glide entry (EV mode). There are 5 stages of Prius operation. These translate fairly directly to the TCH. As a corollary to this work it was discovered that there is "special thing" that happens at 80 degC. At this point the coolant loop opens and the engine is forced to run to pump the coolant through the entire system.
So every glide failure I found during my review was either do to being in stage S3 instead of stage S4 or the coolant loop opening.
Now as far as the SG problem goes. Its a SG software bug... clear and simple. To see this you need to look at a SG with FW rev 3.01 and another with FW rev 3.15. Take both units and set it to Liters instead of gallons. Start your Camry and shift to N before the engine lights. Note that on that on FW rev 3.01 LPH registers as 0.0 and on FW rev 3.15 LPH registers as 0.15 (I think). This is a clear example since it can't be attributed to rounding error. If the SW was in sync, v3.01 should register 0.1 LPH and v3.15 should register 0.15 or (preferably) both should register 0.0.
Now on to the OPEN / CLOSED loop question. Using the Prius as a not very appropriate analogy, there is a trick called "Warp Stealth". Basically if you have XGauge, you program up "gps" to show gas pedal pressure. Now on both cars at about 45 miles per hour, you come off the gas and then re-apply till your pedal pressure reads 10%. In both the Prius and the TCH this will cut the injectors (IGN=5) set the car to OPEN loop and register all yellow lines (like your in EV) but the RPMs will read 900ish. What's happening is that the PSD is using the touque from the MG sets to pull the ICE around at at certain RPM. The reason it does this has to do with an RPM limiter on one of the MGs. Now as you go higher MPH this trick becomes more difficult to pull off. It can't be done at all in the TCH at 70 MPH and it can't be done at all in the Prius at 90 MPH. I suspect at a certain point the MG sets just can't keep pulling the ICE around, so just orders it to idle instead of allowing it to fuel-cut.
Now this doesn't mean you can't hit high numbers at high speed (assuming that is the nature of your question). If you start watching IGN you will see it serves as a precursor for when your MPG is about to jump. Over 50 miles per hour if the terrain allows, the RPM can drop below 1200 RPM and IGN can drop 19. You'll usually register between 50-90 MPH in this state and it can be maintained for miles.
Anyway... Hope that helps.
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