Forgive me is this has been covered before, but I'm wondering if when the A/C is kicked on by battery cooling needs, does the climate control system also start kicking out cooled air - i.e. if you don't have an A/C mode selected on the dash panel control, do you get A/C discharged air anyway if the battery sensor engages the A/C clutch?

 

No, you must turn the climate control system on for it to put out cooled air. Also note, the heater coolant pump stays off only when the the sysem is in the off position. Any other position the pump will run. For this reason, I never use the vent mode, just roll down the windows.

GaryG

 

The A/C has a valve with 2 zones. It can cool the back without the front, and vice-versa.

 

That confuses me.... woudln't that mean I'd get heat when I was in vent mode? I don't so I'm missing something. I use the vent all the time. Also... why would there even be a heater coolant pump... there already is a water pump... All you need is a valve to shunt the water to the heater core, why would you need a pump for it, its already under pressure.

There is something I'm missing here.

 

Yes Tim,you are missing things!

GaryG

 

I know there are two (2) coolent pumps.

One for the engine and heater core...
One for the electric motor and electronics...
These two operate independantly.

That's all I'm aware of. I do not think there is a third pump just for the heater that GaryG thinks there is.

Running the cabin heat from a cold start will slow down the engine getting hot. The engine coolent pump "may" stay off for the first few minutes after a cold start. Once the engine is hot ( to normal temp ) the coolent/heater pump is going to be running no matter what, so after 5 minutes or so, it does not matter what setting you put your dash controls on.

Also, I just read that the A/C clutch will activate for the first few seconds after a cold start ( or 8 hours of off time ) in all temperatures above 25'F. This is done to "purge" the system of any refridgerant condensate that may collect in the compressor. I've seen this happen a few times, and thought maybe it was a glitch... but no, it is done by design.

 

"Illuminating" as always Gary... (It illuminates something alright--a lack of class).

 

Thats what I thought as well... the two cooling systems are separate one high temp one lower temp, they will need separate pumps.

I'll be ****ed if I know why there would be a separate pump for the heater core.

 

I guess I read the OP's question a bit differently.

If one has the A/C "on', but it isn't running because you are in EV mode, and then the batteries need cooling so the system starts A/C cooling the batteries, will you then also get A/C cooling in the cabin? In other words, if the battery "zone" is active, and the climate controls are set for normal A/C, will the cabin "zone" also became active?

I think the answer is "yes".

 

WaltPA, to clarify - my question was whether the front AC system kicks on if activated by the rear (battery) thermal sensors. It appears that there are front and rear zones similar to a minivan front / rear system, so if the AC compressor is on, either zone can operate independently.

I guess I'm more confused than ever on the water pump logic. Maybe this is covered in the shop manual, if anyone has access.