In regards to the defogger changing the drive mode from EV to combustion does anyone know why it does that and how to stop it from happening?

 

Defogging requires a reduction in HUMIDITY. That is best done in vehicles by running the air conditioning system. And often, that triggers the ICE engine to run.

Most cars in the past 20 years run the A/C with windshield defogging. With the RX' 'Climate Concierge' it's gonna happen without you necessarily being aware.


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If this is different with the PHEV 450h+, someone can chime in and teach me something!

 

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thanks for the reply. We have been running the aircon without the ICE activating so far, its only then we started using the defogger that it started to occur. We have had plenty of lithium battery remaining as well (I thought it could be that)

 

You can manually select the defogger duct position if you don't want the engine to start. It's not as effective as with the engine running, but it does work. Pushing the front defogger switch is asking the system to clear the windshield as quickly as possible, which requires heat from the engine.