Just interested if anyone of the Priuschat expertise can explain to me; My 2007 gen2 has generally a high value (40-60%) for idle Calculated Load. My 2005 has a value of 20% - and it’s almost identical to the Engine Load value, while the 2007 value diverts atleast +100% from the engine load value. The 2007 engine runs great and LTFT are within 2% and the MAF shows the same values under the same scenarios. The MAF sensors are refreshed/cleaned - and when they are switched between the g2 vehicles it shows the same abnormality for the 2007. Throttle body clean and fresh, same effect after reset of learned values. What else is involved for this value? When I added a used MAF sensor (they have maaaaany OE numbers for many different vehicles…) it showed the same values. For knowledge
Calculated load was originally "current airflow divided by peak airflow"(with BARO correction). Google says that the car makers used different implementations of this, so the government changed the calculations to be more "defined" (ie, more corrections & restrictions). That might have happened between 2005 & 2007. Absolute load is "current air mass divided by theoretical max air mass for the RPM" - it's a rough indication of Volumetric Efficiency. Personally, I don't pay much attention to those PIDs when looking at the data for diagnostics. Posted via the PriusChat mobile app.
Thanks for the replies, much appreciated. Please add anything even slightly relevant if you know more of this Toyota calculus. Yes, identical (unlikely with unlimited decimals…) Why would that be relevant? Could be, but the MAF reading is very closely matched with my other g2 when compared. Yes, that is what makes it a bit mystifying to me. It’s not at all affecting the engine performance, and both cars reach 100% calculated load when flooring the pedal/accelerating hard. Seem to me to be some other value included in the 2007 Calculate Load (actual wording…) ECU calculation, perhaps MAP and idle rpm (which btw always is commanded to 1300 rpm over here…).
Found this very information packed channel for OBD analysis. Video below, collapsed is the informative description from the video.. Naturally Toyota could possibly have another calculus. It does not explain my cars different values (that’s for me to decipher, any tips welcome), but goes through the actual data and is very educational; Spoiler: CALC LOAD ABSOLUTE LOAD ENGINE LOAD Both the Calculated Load (CALC_LOAD or ENG_LOAD) and Absolute Load (ABS_LOAD) PIDs hold value in the diagnostic evaluation of the engine’s breathing capability. Meaning they both tell a similar story, but in a different language. Calculated Load reflects how the engine is breathing during WOT at any point in time (regardless of elevation, engine temperature, air temperature, or rpm). This value represents available torque capacity, and it is compared to the engine’s maximum torque capacity (as in “100%”). The outcome is basically an expressed percentage value of maximum breathing capability. Absolute Load is based on the engine’s swept volume. For instance, a 3.0L engine is said to be 100% volumetrically efficient if it moves 3.0L liters of air in one engine cycle. If we turbo charge that same engine, it can move far more air (because it is being force-fed under pressurized induction from the turbo charger). That engine (under full boost) may reflect 190% Absolute Load but, that is the most it can breathe (meaning, 100% Calculated Load).
The difference between idling idly and 'idling' with several amps into the traction battery can a couple HP or so.
