salman

Thanks for the update . . . about the pending update. And sorry to hear that the wiring harness reports don't seem to be addressing the cause of the problem. A software problem or a twitchy relay switch make more sense to me as a likely cause of our 12 volt problems than wiring harness problems or frayed wiring. A problem with wiring harnesses or a frayed wire would, I think, produce other effects besides a battery drain, like flickering lights or radios that flicker on and off, etc. While that sort of wiring problem could well happen in any given car, it does not seem to match the experience of most of us who have had dead 12 volt systems. Most of us have not reported other electrical problems coincident with or preceding the dead 12 volt episodes. I wish we knew at least a little of the story behind how & why the Ford engineers came to decide it might be a software problem. While the service techs at dealerships often will explain to us what they have tested and tried, Ford central does not seem to let out much information.

The TSB calls for adjusting the latch because people were having trouble with the lid not closing fully or properly. I know about the TSB because of dead 12 volt problems. Ford's hotline for service techs recommended performing the TSB in case a hatch not closing could have been draining the battery. No reason to think that was the problem. There is not yet a publicly available list of TSBs that I can find. So far I think we need to depend on the dealer service departments.

TSB 12-12-06 calls for adjustment of the latch on the hatch lid. Ask your dealer to look it up.

JPD Thank you for the details. There is no reason for any of us to call your dealer, but it will be important for us to be able to tell Ford where your car was diagnosed if our Ford reps are not as helpful as your dealer and the visiting engineer. Please let us know if the repair solves the problem.

JPD This is really great news. It would help us all immensely if would please give us some additional information. 1) Please tell us a little more about the 12 volt failures you experienced. You mention two episodes of 12 volt failure, but you also say Ford was on the verge of offering a buy back or exchange, which suggests the problem must have been going on for a long time with many service visits. 2) Please tell us what city you are in or, even better, please tell us the name of your dealership so if/when we need to reference your case to Ford we will have enough information for them to locate the case record. Naming your dealer would positive for them, since you have good things to say about their service. 3) Last but not least, please tell us if the repair to chafed wiring at the rear hatch fixes the 12 volt problem for you.

Thanks for this information. My fingers are crossed that maybe they have spotted the problem. If you can, please try to get them to tell you which 3 wiring harnesses are in question, especially if they think it fixes the problem. (all 3 related to the radio?)

Yes, I agree with those points. It would be better to have a cleaner thread in which people post more information (about episodes, repair experiences, and trying to figure out the problem) with less chat that does not impart new or additional information. But it is an open forum with no moderation to keep discussions on point, so I don't think there is much one can do about that except hope that people exercise self-restraint to stay on topic and devote a little time to acquire and share information.

There is a dead battery roll call thread, abandoned for some time now. 12 volt failures have hit every kind of CMax with varying option packages, with few and many miles, in warm and cold climates, with and without accessories plugged in. There is no simple pattern. We can't figure out an incidence rate on this forum. The posts are voluntary self-reporting by people who choose to search for and log into these threads. We won't get a count of all the 12 volt problems. Personal messaging everyone who has posted about a 12 volt problem on any thread (and there are a handful with such reports) will get spotty results. Some posters are gone. Others don't check their messages. And not everyone wants to post information (or more information). Posts about cars without problems do not help. Most cars have not had 12 volt problems. We know that. We cannot possibly get a count of cars without problems from volunteers who come to this thread since the likelihood of coming to this thread and participating in it is very low if your car does not have 12 volt problems. What I think is helpful is to have people who have experienced 12 volt problems post as much information as they can about what happened, when, where, and then about Ford's responses to the problem. We won't get an incidence rate, but it is very useful to be able to say we know about many cases, and more useful to know details about a bunch of cases. It is also useful to know what has been tested and what, if anything, provides a cure (battery change outs have helped in some cases, but not in others).

Thanks. That is helpful information. Don't underestimate the extent to which the service manager will respond to polite and persistent questions about the extraordinary efforts they are making to diagnose your car, which is very difficult to do and you appreciate so much because of the great inconveniences you have absorbed through these repeated 12 volt failures. I think that kind of spin of the questions will get you details if you ask for details, especially since your service department has already been apologetic about not taking the issue more seriously when you first brought it in.

Flatbat It would be extremely helpful to many of us if you could find out more about two things: 1) Confirming that the service department has connected the car's computer to monitoring engineers or service techs at a central Ford office, and finding out as much as you can about how they do this and why they decided to do it. 2) How the service department (and remote monitoring team) monitored error codes over the weekend. It is one thing to monitor the engine and other things by computer when the car is on and mechanics are present, but quite another to monitor the car over 2 or 3 days. Different equipment is required. My understanding is that typical Ford dealerships commonly have equipment to monitor cars only when they are turned on and in the presence of mechanics. That is what my large dealership in Los Angeles says they have (Buerge Ford). But you and Mbedit have reported that your cars were monitored over 2 or 3 days or longer. It would be hugely helpful to know how your dealership did that.

Flatbat Please try to get more information from your dealer about what they and Ford are trying to do and please share it with us. It would be enormously helpful to know from your dealer how Ford is trying to work on the car remotely and why they think it is a software glitch. With that information in hand we all could ask our dealers to do the same with our cars (i.e., have Ford check it out remotely). (a thought added later: by working on it remotely might the service manage have meant only that he had contacted Ford engineers through the service hot line?) There is always the chance, too, that the dealer won't be able to tell you how Ford is working on it remotely because they are not doing that - it might not be possible to do it. I am not claiming that is the case, only saying that your experience of multiple 12 volt failures and multiple evasive responses by Ford gives you the moral right to ask and be told what the dealer and Ford are doing try to diagnose your car. Information is critical for just the reasons you explained. When car owners do not have information in our hands, Ford will first claim owner error and second it will claim that each case is isolated. All that nonsense gets cut off when we tell Ford that we can identify specific cases located at specific dealerships. Not only does it cut off the evasive nonsense, but it also tells Ford that there is a network of people talking in public about the problem, and that has got to make them worry about the prospect of bad publicity for the car if they don't start to take the problem seriously.

My car's build date was October 4, 2012. Advsysal - please keep us posted on what happens, and please post as much detail about your experience as you can. emccabe - It is a long thread to read through. Most of the dead 12 volt cases have not had extra accessories plugged in. That's always been the first variable to check and eliminate.

True enough for starting the hybrids under normal conditions . . . . but then there is this bug causing dead 12 volt systems in what seems to be a non-trivial minority of C-Max cars. The problem has not been successfully diagnosed yet. The cause could be the smaller battery size coupled with the slower re-charge rate from the stepdown converter (slower than a traditional alternator). Or the cause could be twitchy relay or circuit, or a combination of a small battery and circuit problem. Too bad we couldn't send in questions

Mike51 Yes, it is a Ford problem. I do not think anyone who has posted on this board has blamed a dealership. The reason I asked for your dealer's name was not to blame the dealer, but so that all the rest of us can tell Ford that we know this problem has happened to a specific dealer as well as to owners in various locations and at particular times. The fact that it happened to a dealer taking a customer on a test drive is significant. It eliminates any blame-the-owner game. It potentially has a more direct impact on marketing. And dealers, if they know about this, would be more energetic in asking Ford for help (some dealers are energetic and aggressive in their testing of cars brought to them for service, others are not). My experience and that of several others is that Ford has been claiming that these are all isolated occurrences that are unrelated to each other. Information is important. Ford is not sharing much information, not with us and, as best as I can tell, not with its dealers and service departments. Having information about other cases and the extent to which many of us have tried to get the cars fixed and tried to get information out of Ford seems to have been very useful to you. Just as you learned from reading our posts on this forum and now know your case is not isolated to you, we all stand to possibly learn from information that you could share. There is no need to attack your dealership and I am not asking you to do that. Since your dealership has been so great, you would be singing their praises if you mentioned their name. but it is all up to you. That's why i prefaced my request for more information with the phrase, "If you don't mind." If you do not mind, it would be useful for the rest of us to have more information about when your events happened and any other details you can relate about what your dealership tested and how they tested it.

Mike51 If you do not mind, please post a few more details. When did your three 12 volt failures happen? What is the name of your dealer where the dead battery happened on the test drive? This information will help us all if/when we need to talk to Ford again. It will allow us to give details about other cases of 12 volt failure. Moreover, the dealer getting hit with a dead 12 volt system should be a significant prod for Ford to act. Quite a few of us have had a hard time getting information out of Ford. Customer Service at Ford seemed very responsive at first, but when I started asking about other cases and supplied identifying information about those cases, then suddenly the flow of information from Ford turned false and then stopped altogether. Although I still believe Ford must want to figure out and fix these 12volt problems to protect the reputation of the cars they are selling, it also seems to be the case that they are not sharing information about the problem. Probably they do not want to admit that they cannot figure out the cause.

Mbedit That is a very interesting story about Ford refusing to give you paperwork on their repair efforts. I suppose they are probably in their legal rights to not give you any more paperwork on a car they have bought back from you. But it doesn't sound very open of them, to say the least.

Andrewwx The Ford customer care rep I dealt with is Mark Coll. He handles Los Angeles, nearby to your in Venture. Please let me know if you get him as your new rep. Please keep us all posted.

MikeB That's a good set of deductions you are making and I think you might be right about the converter being on while charging the LiOn. Certainly you are right that some part of the computer must be on to regulate charging of the LiON, and that would draw 12 volt power. So it would make sense that the converter would be re-charging the 12 volt to prevent depletion. i am hoping Ford used good sense in designing the car! The 12 volt problems are obviously hitting a minority of the C Maxs of every flavor. From the postings it seems to hit more non-plug-ins, but we can't tell if there is a different rate of incidents. Not enough data and only self-reporting by people like us who feel like going on the web to figure it out. If ziggy knows of 2 energis out of GE's 2000 that have been hit, that is .1%, but if his pool of knowledge is not the 2000 GE Enrgis but, say, 10 or 50 or 100 in his local GE fleet, then the incidence rate would be greater. Even then we would need more data. My sense is that we are seeing a non-trivial rate of incidence overall (i.e., not random one or two off problems, but something that must have a more systemic cause, whether too many bad batteries out of production or a bad circuit board or bad circuit/switch/relay design). Your thinking through the way the Energi probably recharges the 12 volt battery might prove helpful in trying to isolate the cause of the problem. Thanks.

I do not have an Energi. How do you know that the converter is on while you are charging the LiOn battery? Isn't the car turned off? I agree there seem to be fewer postings about Energis with dead 12 volts, but I think it is hard to read the data. There are some cases of dead Energis. With both the Energis and the non-plug-ins, we only know of the cases that have been posted and can only speculate about the overall rate of failure. This is one of the reasons why Ziggy's post is potentially important. GE bought 2000 Energis. Ziggy says he knows of 2 case of 12 volt failure. Now that means either 2 out of 2000 or, perhaps, 2 out of a smaller number if his universe of case knowledge is local rather than national. We all need more information. And Ford is not giving it. I have asked Ford Customer Service to look into cases like Mbedits in Wilimington NC. Ford came back and told me that they knew about that case and that it was merely a matter of a part delay!!! I shot back that this was not accurate because 1) Ford could not diagnose the problem and hence could not identify what part needed changing, and 2) For would not buy back the car (or ask for it to be shipped back to Michigan) if it knew what part it needed. And in responses to this information I have received only silence as a response.

Ziggy Since your car is part of a GE fleet purchase, who takes care of getting Ford to do the warranty work? You? Someone in GE's motor pool or fleet management or whatever GE calls it? If it is GE, then they might get a lot more access to Ford than we individuals get. If this is GE's car, then I know I am asking a lot of you when I ask you to please try to get as much information about Ford's handling of the problem as you can. You would be helping GE fleet management, too, by telling them about the dead battery experiences reported here. As for your use of the plug-in charger for the big LiOn battery: That is the car's high voltage system and it only recharges the 12 volt battery when the car is on and running. It does so through a step down converter that is regulated by the car's computer, and the computer is run off of 12 volt current. When the 12 Volt battery is dead (or not strong enough to switch a relay), then none of the car's systems turning. That is what charging the LiOn battery does not help, but a brief boost to the 12 volt battery would start the car.

Pomfrey Please call Ford (both your dealer's service department & Ford's Customer Care line) and let them know you have had dead batteries twice, if you have not already done so. As you can see from the dead battery threads there are many of us who have had the same problem and we are trying to get Ford to figure out the cause and correct the problem. They are more likely to put their engineering teams on it to the extent they face the fact it is not just an isolated problem effecting only a couple of cars.

The 12 volt battery is 12 volts. The LiOn is high voltage. The power in 12 volt outlets in the car is 12 volts and comes from the 12 volt battery and, when the car is running, from a step down converter that converts high voltage from the LiOn battery down to 12 volts. When the car is off, any current in the 12 volt outlets is from the 12 volt battery and the connection to the step down converter is off. Here is what can possibly be done, apparently tested by some posters: A 12 volt battery booster can be plugged into a 12 volt outlet rather than connected to the jumping posts for the 12 volt battery (posts are under the front hood, battery is in back under the cargo area). The booster sends power through the 12 volt outlet to the 12 volt battery, and all that is needed usually is a quick flash to start the car.

Andrew The California Lemon Law uses 4 repair attempts as a guideline for determining when provision of a replacement car or buy back is legally enforceable. This is your 4th repair attempt. I hope you will look up the Lemon Law and then tell your dealer and Ford Customer Care that they are coming up against the Lemon Law in your case, and demand that they pull out the stops to fix your car. Let them know that you know about Mbedit's case in Wilmington NC (the town and reference to the buy back Ford offered & Ford's request to take his car back to Michigan is sufficient for Ford to locate the case file). In addition to the pressure this will put on them, they also should be comparing notes on these cases to isolate the cause or causes. My experience, sad to say, is that Ford is not communicating adequately with itself (dealers - customer care - engineering) to compile and share information to solve this 12 volt problem and another problem I have had with the Global Open feature opening the windows on its own. You have a special opportunity because 1) your dead car will be towed so they will see a dead car, and 2) being on the verge of being able to invoke the Lemon Law will give Ford added incentive to try to fix the car.

Mbedit some of us have speculated about relays in the CMax. one poster says there is some "consensus" about a bad relay among posters about troubles with 2004 Thunderbirds, but I have not looked into that. top right corner of the page there is a search function. I typed in "relay" and searched this thread. One poster, Bob999 (I think) provided some explanation for his hunch. No determination yet that a bad relay is the cause.

Jonathan There is lots of relevant information in this and the other battery threads: 1) please call Ford's Customer Care center and log your experience there and ask for help, as well as bringing the car to your dealer. The Ford # is 800-392-3673 2) ask your dealer's service department to call the Ford tech hotline. They will have the number. 3) Jumping the CMax does not require 5 minutes. As soon as the terminals are connected you can start the car because the 12 volt battery does not crank the engine via a starter motor, as in gas engine cars. The 12 volt merely awakens the CMax's electrical systems so it can draw power off the LiOn battery. 4) Although there is some reason to wonder about the quality and condition of the 12 volt batteries in the CMax, and also reason to wonder if there is a phantom power drain that saps the 12 votl battery, I am inclined to agree with you that there might be a relay or switch that is getting triggered to shut down for some reason (and then is rebooted when the car is jumped). But, so far, despite dozens of cases of dead 12 volt systems, neither we nor Ford has an explanation for what has been going wrong. The thread is full of posts about these problems - well worth reading before you talk to your dealer and Ford Customer Care.