Hello fellow Fusion Hybrid forum members! I just purchased a used grey 2010 Ford Fusion Hybrid (base trim) w/ approximately 48,000 miles and have been very pleased with its performance. The car runs great and gets much better gas mileage than my old car (a 2009 Hyundai Elantra SE).
The one thing that is slightly troublesome is the yellow/orange-ish warning message (always accompanied by an audible warning chime that sounds one low note and one high note several times and is quiet but noticeable) that appears periodically.
The funny thing is that the warning message appears and disappears so fast I didn't even notice it the first few times. It finally stayed just long enough (but not more than half a second) so that I could read the actual message which said "High motor temperature".
Looking up the error message on this forum and other Internet sites, most people who have experienced problems after the message appeared have indicated that they needed to have the "Electric Motor Cooling System Water Pump..Part number 8c419" component replaced. However, many people who reported having that problem were driving Ford Escape Hybrids (FEH) instead. The FEH M/E cooling system, as I've also read on multiple Internet sites, operates differently from the FFH M/E cooling system. The FFH high-voltage battery is air-cooled using cabin air, while the FEH high-voltage battery is water-cooled using the same water pump as the electric motors.
I have tried to drive in such a fashion so as to better isolate the problem, and I have noticed the following quirks. If I drive slowly in EV mode, the message never appears. If I drive at typical city or highway speeds, the message appears periodically but never remains for more than half a second (and no other warning lights light - e.g. the wrench icon or the engine icon). If I drive using EV mode on the highway (at under 47 mph), the message rarely appears. However, I can usually reproduce the problem when braking on the highway: if I apply brakes (the regenerative braking icon appears) and slow down to a stop or near stop and then press the gas pedal to accelerate, the warning message usually always flashes and the warning chime almost always sounds.
I have several questions, but my first and foremost question is this: can any other Fusion Hybrid drivers/owners/mechanics/etc. confirm that this usually an indication that the MECS water pump (the part referenced above: 8c419) is faulty or failing?
Should I be concerned about it even though the warning message never remains on the screen (if it even appears, it just flashes)? I can live with the warning chime. If the issue is with the MECS water pump starting to fail, then should not driving in EV mode exacerbate the problem and leave the warning message permanently on the dash? Since I have noticed it especially often after braking from highway speeds and then accelerating, does this help narrow down the cause of the problem? If the problem is a flaky or faulty temperature sensor, is it possible to adjust the warning temperature before the message appears a little higher?
Another major question I have is: would this water pump be considered part of the "powertrain" system for the vehicle? The original Ford 60 months/50,000 mile powertrain warranty is still in effect, so if the water pump is part of the powertrain system, could I have it repaired or replaced under warranty (I also have a 60 days/2,000 mile powertrain warranty from the dealer I purchased as I live in NJ which has good used car laws)?
My final question is semi-related but applies to the CVT transmission of the vehicle instead. I recently purchased a 3rd party warranty from the Auto Warranty Agency. Does anybody have familiarity with 3rd party warranties (esp. from the Auto Warranty Agency) and their coverage? In particular, the warranty contract states that the transmission is covered (and I did pay the hybrid surcharge). However, the warranty did not specifically address CVT transmissions. Does anybody know if CVT transmissions would be covered by transmission warranties? The line from the contract reads something like "All internal components of the transmission that require lubrication for operation". I am a bit worried because I read that line aloud at work, and a coworker said CVT transmissions do not require any lubrication and thus would not be covered.
My thanks in advance to any fellow forum members who could shed any light on any of these topics.