Please comment if there's something wrong in the following logic:
1. PCM needs to be in Closed Loop in order to generate LTFT's (via STFT's)
2. There are several preconditions that needs to be fulfilled in order to PCM to be or to stay with Closed Loop. Following parameters define most relevant ones:
__2.1 Engine temperature + bunch of other parameters, such as OLFA
__2.2 MAP boundaries (?)
__2.3 PE enable MAP value
__2.4 PE enable TPS value (hot/cold)
3. Whenever engine enters into PE mode*, no LTFT's are generated anymore
__3.1 PE mode* equals Open Loop in practice, right?
__3.2 For example in my car, TPS % for going PE is 55% at 3600 rpm
Now, to my understanding this means that in the VE and in the areas of low vacuum level (high numerical value, i.e. somewhere between 85...105 KPa) no LTFT's ever occur. This is because on those areas in the VE, the engine is always in Open Loop and thus it does not generate LTFT's.
If, and only if what I say above is true, then I do not understand what is the logic for positive LTFT's affecting WOT. Does the PCM remember the last positive LTFT just before PE mode is triggered by, say, throttle position change?