triangles
Posts: 1062
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: Dead 12V battery then traction control freaks out

Tue Nov 06, 2018 7:56 pm

Well my FFE is back to it's old dead 12V antics. :evil: Updated details in my 8-22-17 timeline post. This time the culprit seems to be the BECM Battery Energy (or Electronics depending on what reference you believe) Control Module. I may have gotten lucky and caught an intermittent problem. I reset the BECM fuse and all seemed ok again. We'll see if this issue comes back. I believe the BECM is in the upper battery pack. Does anyone know what it does?
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

triangles
Posts: 1062
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: Dead 12V battery then traction control freaks out

Wed Nov 07, 2018 8:21 am

So I charged the 12V overnite unhooked from the car. And performed another draw down test. 1.32A. I didn't have time to see if the BECM was still the culprit. So I hooked the 12V back up and when I got in to go to work, I got the yellow wrench and battery depleted message shown below.
ImageImage
Car had been parked a few days earlier with a 77% charge. I couldn't get a green ready to drive indicator :( So I plugged it in to charge and the car indicated it would take 4.6 hours to charge! :shock: 45 minutes later I get a charge complete text message and observe a 100% charge with the battery showing yellow and 1 mi indicated range on my phone. Going to read the DTCs at lunch and see if I can get her to drive.
Image
update: There was a boat load of DTCs all related to low 12V or lost communication (probably due to low 12v.) Nothing specific about the HV battery and no errors from the BECM. The car started and I could drive it but it was not happy at first. Started out with 1 mi on the GOM and just slowly went up from there as I drove. It got up into the 40's before it stopped rising. I took the pic below as it was rising.
Image
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

triangles
Posts: 1062
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: Dead 12V battery then traction control freaks out

Fri Nov 16, 2018 11:52 am

Should have posted this on November 12:
Since my last post I figured out that pulling the F11 fuse while the car is on is what causes the car to freak out and think the HV battery is depleted when you next power on the car. I did some more trouble shooting and it looks like the BECM is indeed the culprit. Car still functions normally but when off the BECM causes a 1.3A load on the 12V battery. On November 8th I made an appointment for first thing in the morning November 13. I dropped it off after hours November 12. Last word from the dealer was on November 15 that diagnostics weren't conclusive. I take that to mean they are waiting on Ford to tell them what to do about the BECM. Does anyone know where the BECM is located in the car?

Updated this 8/22/17 post timeline with details.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

elec2017
Posts: 20
Joined: Mon Apr 03, 2017 10:29 am

Re: Dead 12V battery then traction control freaks out

Fri Nov 16, 2018 5:15 pm

Good luck, hope the dealer can fix it once for all.

triangles
Posts: 1062
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: Dead 12V battery then traction control freaks out

Wed Nov 21, 2018 8:16 pm

Not sure how I screwed up troubleshooting but it turns out my TCU is bad again. Not worth spending $700 for a 4th TCU that might last another year if I'm lucky. So I live without MFM, GO times, and Value Charging. Are the TCU's that shitty that they can't last much more than a year or is their something wrong with my car that's killing the TCU?
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

Dobrinia
Posts: 59
Joined: Fri Nov 02, 2018 2:14 pm
Location: Belarus, Minsk
Contact: Website

Re: Dead 12V battery then traction control freaks out

Sat Feb 23, 2019 2:29 am

I have a similar story, TCU discharges the battery.
Perhaps the fact is that the car is in Belarus (Europe) and AT & T is not available here...
Yesterday there was an SSN error after the battery is low ...
I charged a 12v battery and the error disappeared. I drove 100km and put the car in the garage. In the morning, the battery voltage was 12.9 volts, but the car did not start, SSN error.
After charging the battery up to 15 volts, the car started up again without any errors.
For this car you need a battery with a working voltage of more than 14 volts, and not 12 as in gasoline cars?
I use translator. Sorry for the mistakes.

kalel14
Posts: 116
Joined: Sat Jan 09, 2016 4:05 am

Re: Dead 12V battery then traction control freaks out

Sun Feb 24, 2019 3:45 am

Dobrinia wrote:I have a similar story, TCU discharges the battery.

For this car you need a battery with a working voltage of more than 14 volts, and not 12 as in gasoline cars?
No. Mine starts with 12 V all the time.

rjhunter
Posts: 4
Joined: Wed Feb 27, 2019 3:25 pm

Re: Dead 12V battery then traction control freaks out

Wed Feb 27, 2019 3:50 pm

Hi all. I'm new to this forum, so I want to first thank everyone who has taken the time to detail & discuss their issues and fixes. I have a 2014 FFE with a 33.5 KWh battery (replaced under warranty by previous owner in Sept 2017) with 50K miles on it. I have owned this car for 11 months, and I have been dealing with 12V battery issues since October. As described by others on this post, my 12V battery seems to randomly die (dropping down to ~9V) after sitting unplugged for 7-8 hours. Ford has replaced my 12V battery twice under warranty, and assured me that it was just a bad battery, and there is nothing wrong with my car. But I'm quite sure this has nothing to do with the 12V battery.
I've noticed a pattern over the last 5 months that the 12V battery issues seem to correlate with MyFord Mobile issues (losing connection). I have to constantly pull the fuse on the Telematics Control Unit (fuse F1) to reset the TCU so that I can connect again. I recently used a Klein Tools model MM200 along with a Fuse Buddy 301M to measure current at the fuse level when the car is on and when the car is off. As per Triangles advice, I was sure to measure after 40 minutes as well. What I found was that all units that I tested (I only measured fuses that were 10A or lower) read zero amps when the car was shut down. But the TCU never shut off. It constantly bounced from 0.03A up to 1.3A, but mostly sitting round around 0.04A. I pulled the TCU fuse and left it out. It's been 3 days now, and so far, I have had no issues with the 12V battery.

Magnetoreluctance
Posts: 21
Joined: Wed Nov 23, 2016 7:01 am

Re: Dead 12V battery then traction control freaks out

Tue Mar 05, 2019 7:20 am

Just wanted to add my experience to the thread. '13 FFE, just like triangles otherwise, but fortunately I've only had two instances of a dead 12 volt.

When it happened last September, my dealer charged me ~$700 to replace the TCU with a new one. I'm not thrilled that the problems continue, but I strongly suspect the TCU is still the culprit based on my latest incident.

So my car is currently getting a ceramic coating and thus was left unplugged overnight at the detail shop while it cured. I checked on the car with MFM late last night just being curious, and here we are this morning the car is dead after sending me a text. I'm not going to try and do further diagnosis at this point. It sounds like the solution is just to live without MFM and unplug the TCU. While its nice to have, I don't want to deal with this as an ongoing problem. If there are further issues, I will try and remember to come back to this thread.
2013 Focus Electric - Blue Candy Metallic

triangles
Posts: 1062
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio

Re: Dead 12V battery then traction control freaks out

Fri Oct 18, 2019 7:54 pm

To everyone having 12V issues due to the TCU I have found a Pseudo fix. No, I have no solution for Ford's shitty TCU but at least I have found a reasonable way to prevent it from killing my 12V battery.

Over the last 11 months since I pulled the F1 fuse I have pondered various ways of powering the TCU separately from the car's 12V system. Everything I came up with from using an arduino microprocessor and an auxiliary 12V battery was some combination of too expensive, too complicated, or just plain not a good idea. Then it hit me I was overthinking the problem. If I could only find an "affordable" low voltage disconnect that itself would not drain my 12V battery (ie. draw practically no current) and I could set it at a relatively high disconnect voltage, that would be the simple solution. I set out to see if this magical unicorn of a device existed. I found many cheap low voltage disconnects but their current draw was unacceptably high.

Then the clouds parted and angels sang as I stumbled upon this little gem from Galley Power. :lol: It was a little more than I wanted to spend at $46 but it fit what I was looking for almost perfectly. On the high end it can be set to disconnect if the voltage drops below 12.1V and will reconnect at 13V. From what I have read on the interwebs 12.1V is approximately a 50% SOC for a 12V battery. The next lowest setting is 11.7V which I believe is about 40% SOC. Anyway when the unit is in the "connected mode" it only draws 3.5mA. Ford's spec for the car when it is off is a 50mA or less load on the battery. I have measured mine at about 20mA so when my car is off It will now have a 23.5mA load on the 12V battery which is still in spec by a long shot and in theory should be able to sit for at least a month. When the unit disconnects due to low voltage the load drops to an amazingly low 0.26mA

I wanted to do this all without hacking and cutting any wires. I happened to have one of those add a circuit things that you plug into a fuse slot laying around similar to this. I ran the power thru the "added circuit" fuse and to the disconnect. I then fed the output from the disconnect back into the fuse slot for the TCU. In other words I used the added circuit fuse as the fuse for my TCU, then fed this power to the disconnect and the output of the disconnect back into the fuse slot for the TCU. Sorry I neglected to take any pictures and if you don't understand how these add a circuit things work this all probably makes no sense. If I remember I'll add some pictures when I get a chance. Anyway this all seemed great, I soldered everything together to essentially plug into the F1 fuse slot. Then Murphy reared his ugly head. The damned fuse sockets are recessed and the prongs wouldn't reach the socket! :evil: Still not wanting to start chopping wires I resigned my self to breaking out the dremel and carving away the extra plastic on the fuse block that was preventing me from plugging in the add a circuit. I used a nearby bolt that is one of the battery retention bolts for the disconnect's ground wire.

Well it has been nearly a week and knock on wood, I have had no issues with the TCU or a dead 12V battery. I had tossed around going to a lower disconnect voltage setting, 11.7V since that is supposedly about 40% SOC and I would think that would be enough to still start the car. Hopefully it doesn't come to that and things work just fine at the 12.1V setting. I'm not certain if it has disconnected or not but every time I've tried to connect to the car via MFM I have been able to do so.

I updated the details in my 8-22-17 timeline post.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

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