willald

Yes, Ford manual tells you to keep the key in AUX/ACC position when towing. You can't take key out when its in neutral to tow, so AUX/ACC position is what you have to leave it in. As to the read-out killing the battery: Yes, it probably will. Regardless of the read-out, though, these hybrids have other parasitic drains on the battery when key is in AUX position that make this a problem you have to address. Read my (long) post at the top of this page, and jmckinley's posts after that. You'll see where we both have found that due to these drains on the battery, running a charge line from your motorhome to your Cmax is an absolute MUST when flat towing these Ford hybrids. If you don't run a charge wire, you will frequently get to your destination with a dead battery, and require a jump start. Not only that, but 'killing' your 12 volt battery and re-charging it regularly like that will shorten its lifespan significantly. Its not a deep cycle battery, and was not designed to be used that way. You'll be replacing it much more often than normal if you continue that approach. If running a charge line is not an option, only other thing I'd suggest is to plan on stopping every hour or so to start up and run the Cmax's engine for a few minutes. This will keep the 12V battery from getting depleted too much. That is a real PITA, though, I would only do that as a temporary solution until you can get a charge line installed. Will

..Had this update done on our '13 Fusion Hybrid a few weeks ago. Was already very happy with the mileage, never did understand why I saw so many people saying it wasn't good. I was averaging 47-48 mpg driving to work and back (26 mile drive, 'bout 80% highway), as long as I kept highway speeds to 62 or less to let it use EV mode when it can. Now, with the update, I'm averaging 49-50 mpg AND I can run a bit faster on the highways when getting it! I used to have to keep highway speeds to 62 mph to get the good mileage (and get passed a LOT, haha). If I went over that, it would drop down to around 45. Now, I set the cruise at about 65, keep up with traffic a bit better, and STILL get 49-50 mpg. You can count me as one that is VERY happy with this update. Great job, Ford!! :) No, it will not hold EV mode very long at much more than 62 mph. Like already said, its not designed to do that. But, it will stay in EV mode at 65-70 mph fairly well on flat roads or slight downhills. This update allows you to utilize EV mode a lot more on the highway without having to limit speeds to 62. Thats what I like about it. As I'm sure its already been said, there are several tricks to getting this kind of mileage, most of which basically boil down to keeping it in EV mode as much as possible, braking slowly to maximize battery recharging, and staying off the gas pedal as much as you can. If you are a 'leadfoot' driver (like my wife) that has to be the first away from every stoplight and the last one to start braking for a stop...You will pay for that in fuel mileage, and will never see the mileage Ford advertises for the hybrids. LOL, any time my wife drives the Fusion, the mileage average immediately drops to the mid or low 40s! I get back in it and drive it, and its back up near 50. Driving style makes a HUGE difference, especially with these hybrids. Anyway, if you haven't got the update done, you need to. Its a great improvement, IMO. I think its a game-changer for Ford, will really push their hybrid models above and beyond the competition. Will

Well, John, you probably already know this, but: Once you adjust the Readybrake cable properly, the brakes on your Cmax will not drag. Readybrake works fine with or without power braking. If the cable is adjusted properly, brakes should never drag, not even when going down a steep hill. I'm actually a little confused as to why yours dragged at all? That is, unless you just had the cable too tight to begin with, in which case it would have dragged regardless whether or not the vacuum pump was keeping the brakes pumped up. I tow two different vehicles, both with Readybrake - the Fusion hybrid, and my wife's Kia minivan. Readybrake works fine with either of them, even though one has power braking on all the time (Fusion), and the other does not and RB is basically pulling a 'dead pedal'. I have noticed, that I actually get a little better braking with the Fusion than I do with the Kia. Obviously, having power braking on all the time allows the Readybrake actuator/cable to pull on the brakes a little harder, and get things stopped a little quicker. 'Tis one reason I am very glad that Ford designed their hybrid so that power braking stays on all the time. And, yes, you did come to the right conclusion, same one I came to some time ago - With these Ford hybrids, a charge line is the ONLY way to go. Without it, you're going to be replacing a lot of batteries and need a lot of jump starts Thanks for posting back, and correcting what you had said earlier, confirming that your Cmax's power braking is indeed on all the time. I could not understand why Ford would have done that different with the Cmax, good to hear that it is the same. Will

Ah, another Readybrake owner. Cool. :) Yes, installing the cable on these hybrids is a challenge, to say the least. Lots of stuff in the way. I was too chicken/paranoid to try that installation myself, so had a RV dealer do it. Had one dealer, the place I normally work with, tell me flat out it couldn't be done. Said there was too much 'stuff' in the way under the hood (interpreted: they didn't want to do it, 'cause it was too much work). Went to another dealer, they did the (cable) installation and did a great job with it. Very happy with their installation. Was not cheap, but was cheaper than what it would've cost to buy an 'electronic box' type braking system (that I want no part of). I too, am a bit perplexed as to why the brake vacuum pump is active all the time on the Fusion hybrids (regardless of ignition switch position), and is not on the Cmax. Wonder whats up with that? Will

..Then the Fusion hybrids must have a different brake design than the Cmax. I know for a fact that the power brake assist is on and engages, runs (regardless of ignition position) on our Fusion hybrid. I can (and have, in testing) hit the brake pedal a few times when ignition is off, and on the 2nd or 3rd time, an electric vacuum pump comes on, and 'pumps' the brake vacuum back up. Brake pedal stays easy to press when ignition is off, does not lose its vacuum assist like conventional brakes do. I would have thought Ford used same brake design on both the Fusion Hybrid and Cmax, apparently not. Will

Hello, I'm a member of an RV-related forum, and this thread, forum was recently broght to my attention. We've been camping/RVing for many years. Have owned a Motorhome for just over a year, and a few months ago, we purchased a 2013 Fusion Hybrid to tow behind it. Anyway, I know I don't own a CMax, which this forum is intended for. However, I think my experience with the Fusion Hybrid and towing it behind our MH is applicable here and should help some folks. First off, we found out very early (on our first tow) that Ford's hybrid drivetrain (whether its in a Fusion or Cmax) has a parasitic drain on the battery when towing and key in ACC mode. After our first trip (around 4 hours), our battery was dead, like so many others experienced. As soon as we got home from that trip, I put an ammeter across the battery terminal, put key in ACC and tranny in neutral to simulate towing. Sure enough, ammeter reads a 3 amp draw on the battery. I figured, there is probably a way to turn it off by pulling the right fuse, but I really, really did not want to fool with pulling fuses, and chose not to go there. Not how complicated the electrical system is on these hybrids! It is also not a good idea to continue to just let your battery die, and re-charge it. You will regret it later if you do. As already said, these are NOT deep cycle batteries, and using them that way will shorten their life span significantly. You'll find yourself replacing the battery quite often. Yes, you may get Ford to cover the first few under warranty, but getting stranded somewhere is no fun and can be very stressful, regardless who ultimately pays the bill for it. I'm not surprised at all, that many have tried but got nowhere in getting an answer from Ford. I never even tried that, 'cause I knew the answer I would get, haha. I too, thought about the approach some have mentioned here, of over-riding the shift lockout and forcing the car into neutral, and leaving ignition switch off. I chose not to, though, as we just don't know if there are some good reasons why Ford's manual instructs you to leave ignition in ACC position. Some of the notes earlier about an electric lube pump for the tranny makes me think that even more so. My solution, and what I highly, highly recommend: Install a charge line going from your Motorhome to your Cmax's battery and be done with it. Its very easy to do, and works great. Now, I can tow pretty much as long as I want, all day, and battery in the Fusion stays fully charged and ready to go when we get to our destination. As already mentioned, Ford provides battery contacts under the hood, which makes the perfect place to wire the charge line. Just make sure (this is VERY important), that you install a fuse on the charge line on both ends - near the battery terminal under the hood on your Cmax, and on the Motorhome side. I use a 10 amp fuse, but anything from 10-20 amps should be good, depending on the gauge of the wire you are using. Some have talked about installing a diode on the wire also, to prevent current from feeding from your Cmax back to the Motorhome. I haven't done that, but it wouldnt be a bad idea, either. As to braking systems: Ford's hybrid drivetrain (again, same in Cmax or Fusion) has 'active braking' that is on/active ALL the time, regardless of ignition position. Meaning, there is electric power braking on all the time. You have to keep this in mind when selecting a brake system, and setting it up. Some systems just are not designed for this, and will over-brake and damage your Cmax (some brakebuddy models are an example). I highly, highly recommend the Readybrake system (http://www.readybrake.com). Works just fine with active braking, and is the most simple, economic, and trouble-free system you can get. Anyway, sorry this got long winded. Just wanted to share what I had learned on this subject. Let me know if any of you need/want any more specifics of how to do the charge line, or anything else I could help with. Will