Page 200 of my 2012's owner's manual stars EV mode is unavailable if the temperature of the hybrid system is either too high or too low. But exactly what temperature measurement and what cutoff values are used to trigger that lock out? I am aware of Engine coolant temperature HV battery temperature sensors 1, 2, 3, and 4. Inverter coolant temperature (upper and lower loops?) (Temps for MG1 and MG2 also?) So which subset or combination of these temperature sensors is us used to index "temperature of the hybrid system " in the EV control logic? What are the cutoff values? (0 Centigrade seems to be the low cutoff, but even that is not precisely stated.) Thanks in advance for precise info!
as a rule of tomb, the high end for the Hybrid battery temperature would be above 137 fahrenheit, the danger zone. The vehicle's cooling system will never aloud the battery to reach that point in a well working car.
Minimum engine coolant temperature is 20C / 68F in the U.S., lower outside North America. I don't know the temperature band requirements on the other items.
With a infrared temp sensor you can read various portions. The coolant temp is generally quite cool around 100 degrees F. Radiator temps are a little warmer but cooler that a standard engine, I believe the thermostat is also a bit lower, 160F Hotter temps can be found at the block and/or exhaust more closely resembling the standard vehicle. The critical temp is the inverter, it's generally just warm to the touch, if it's too HOT to touch, there is a problem. I haven't done this for several years so all the temps are off the top of my head, so don't quote me.
