Chuckee

On the reply about how good the noise suppression is on the C-Max and the ANC may not be needed. I have recordings that show there is a big difference when the ANC is not operating, especially with engine noise and road noise at 65 mph.

My active noise cancellation in my 2017 C-Max stops working when the cabin temperature rises above 100 degree F. It will not come back on until the temperature drops back to below 90 degrees F. and the ignition switch is cycled off and then on. Dealer looked at it and said no codes were found but the cabin was not hot the day they looked at it. I just found out about the "temperature thing" today.

The 2017 C-Max Energi has been a fantastic car. I've found that by running on the plug-in battery to point A and come back from point A in hybrid mode, I double the range of the plug-in battery and double the mpg of hybrid mode. So I get 50 miles off the battery and 70 mpg----a win-win situation. Also because the plug-in battery charges off of 220 V at 16 amps, I can piggy-back off my dryer circuit to charge the battery. So no expensive 50 amp circuit as is required by electric only cars.

I've discovered the ANC works first thing in the morning when the cabin is cool but fails in the afternoon if the sun is out and the windows are up. I'm trying to get the dealer to go ahead and replace the ANC module and if not, I'm trying to get the module to fail for good by placing the car in the sun for long periods.

My increase noise level of engine and of road happened suddenly. I'm sure it's the Adaptive Noise Cancellation (ANC) but the dealer says it's "normal". I have the Energi and the service manager likely tested it in electric mode where it is quieter engine wise but not road noise. With the Energi, the car runs of plug-in battery until that is depleted then switches to hybrid mode so likely the service manager did his road test in electric not realizing it was in electric. My car is 8 years old and the C-max is not made anymore so I wonder if the service manager is familiar with how ANC works. ANC is an electronic module that samples the interior car noise and tries to cancel it out. I think the speakers is in the back and that is where the road noise comes from. Only have 18K miles so not likely any other problem, and like I said on the same day it changed for quiet to noisy between shutting the engine off and turning it back on after some shopping. Would appreciate any comments by a knowledgeable technician on my issue and how to convince the service manager of the problem.