C-max cabin heater

[Guest]

How does the cabin heater in the c-max work? Is it an electrical type like in the ffe or conventional heater core from the ice coolant? What happens if youre running in electric only mode and you turn on the heater? Does the gom in the c-max plummet like in the ffe? Or does it fire up the ice to make it warm?

 

[jmueller065]

The C-Max Energi has similar glow plugs to the FFE and will use them when you're running in EV Only mode.

If its really cold out (like it is now here in SE MI) the C-Max completely disables the EV modes and runs the engine because the electric heaters simply can't keep up. Even if I remote start the car in this weather with it plugged in it will still start the engine (sadly you can't heat more effectively that you can with fire).

I did that last night: remote started the car to heat it up for a good 30 minutes while it was plugged in. Even though it was plugged in it still ran the gas engine and the electric heaters. In that 30 minutes my battery was down a good 10-15%.

Thus the answer to your question is: Yes it does, and it does eat away at the range (my full DTE for battery only right now reads a paltry 10 miles). It also uses the gas engine when the heater can't keep up.

 

[spirilis]

^ what he said.

IIRC it's a PTC heater similar to the FFE, and the coolant is in a shared system with the engine - fun fact the engine doesn't have a mechanical water pump, it's all electric and there's a smaller aux water pump to circulate the heater core coolant when the heater core loop is in bypass mode (electric heat only).

Someone on the CMax Energi forum also mentioned it has an exhaust heat recovery system that circulates coolant through chambers in the exhaust manifold, but I haven't confirmed this.

More detail here- http://www.fordservicecontent.com/ford_content/catalog/motorcraft/OBDSM1700_HEV.pdf

 

[spirilis]

The Energi PHEV's also have GO Times just like FFE, where it heats the interior using only electric power available from the BCCM (charger), but mind you these only have a 3.3kW charger (air cooled, as is the battery, unlike the FFE).

The GO Times seem to begin the preheat process more than 30min before the set time in my observations. Also there is Remote Start but I have witnessed it starting the engine to heat things up faster when it's cold out.

 

[Guest]

Thank you all for your replies. Very interesting.