TLDR: If you want the "A/C mode with Auto" setting being OFF to take into effect you have manually recycle the A/C mode.
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I found this bug in the settings and thought it might be useful to others especially in these colder months in the northern hemisphere.
When sitting idle with heating in a cold weather I noticed that:
After some monitoring over the OBDII diagnostics it became obvious that the car keeps trying to turn on the AC - despite the sub-freezing temperatures outside. This causes the fan-like sound that can be heard during idle - the compressor spins up and few seconds later spins down. This also makes the engine start more often than needed. (I even wonder whether it may result at higher mpg and more wear on the compressor)
There is a setting in the media display (Customise Vehicle-->Climate) to turn off "A/C mode with Auto" but it is not taken into account - when you turn it off the AC still tries to go on.
After some playing around, I figured out that in order for the setting to REALLY take effect you need to (1)turn on AUTO, (2)turn on A/C manually and (3)then turn off A/C. After that the AUTO will not try to start the AC. Even after turning off and on the HVAC ... even after turning off and on the car.
Now my LC can stay idle for a long time without the engine turning off - and it still maintains the cabin warm because it draws from the heat of the already warm engine (heating is not electric on our LCs).
Here is what I think happens:
Turning off the "A/C mode with Auto" setting doesn't get propagated to the rest of the system when simply changed.
The Auto mode has 4 components - temperature, fan speed, airflow direction, A/C on/off. Changing one of these components manually makes the Auto mode to stop controlling that component but continue controlling the rest. E.g. changing the fan speed manually overrides the Auto setting, but the temperature and airflow direction remain being controlled by the Auto mode.
When you switch the A/C on and off manually you essentially override the fact whether the A/C should be on or off. Apparently during this override the setting "A/C mode with Auto" starts being taken into effect.
Obviously it's a bug that I hope Toyota fixes with a software update. We just need to start reporting it to the dealerships.
------------------------
I found this bug in the settings and thought it might be useful to others especially in these colder months in the northern hemisphere.
When sitting idle with heating in a cold weather I noticed that:
- the engine always turns on after 2-3 minutes and then off
- there is a fan-like noise coming out of the engine.
After some monitoring over the OBDII diagnostics it became obvious that the car keeps trying to turn on the AC - despite the sub-freezing temperatures outside. This causes the fan-like sound that can be heard during idle - the compressor spins up and few seconds later spins down. This also makes the engine start more often than needed. (I even wonder whether it may result at higher mpg and more wear on the compressor)
There is a setting in the media display (Customise Vehicle-->Climate) to turn off "A/C mode with Auto" but it is not taken into account - when you turn it off the AC still tries to go on.
After some playing around, I figured out that in order for the setting to REALLY take effect you need to (1)turn on AUTO, (2)turn on A/C manually and (3)then turn off A/C. After that the AUTO will not try to start the AC. Even after turning off and on the HVAC ... even after turning off and on the car.
Now my LC can stay idle for a long time without the engine turning off - and it still maintains the cabin warm because it draws from the heat of the already warm engine (heating is not electric on our LCs).
Here is what I think happens:
Turning off the "A/C mode with Auto" setting doesn't get propagated to the rest of the system when simply changed.
The Auto mode has 4 components - temperature, fan speed, airflow direction, A/C on/off. Changing one of these components manually makes the Auto mode to stop controlling that component but continue controlling the rest. E.g. changing the fan speed manually overrides the Auto setting, but the temperature and airflow direction remain being controlled by the Auto mode.
When you switch the A/C on and off manually you essentially override the fact whether the A/C should be on or off. Apparently during this override the setting "A/C mode with Auto" starts being taken into effect.
Obviously it's a bug that I hope Toyota fixes with a software update. We just need to start reporting it to the dealerships.
