Stop Safely Now / Won't Start

[Joe Tennies]

So, I had the same issue as many others. I had the problem for a while, and it was a case of cold weather (sub 10 degrees F). Left the Mach E outside overnight and wouldn't start in the morning... eventually it warmed up and the car started fine. Drove it for a bit, and it stranded us at church on a relatively cold day after less than 3 hours (not a crazy long church... just had a lot of prep work before it). Eventually got it started and took it into the Ford dealer. They installed some software updates related to the screens not shutting off. Didn't see the issue again for a few weeks.

Then this Sunday, I got home left it in the driveway again, and it wouldn't start again Monday morning! Finally got time to look at it today (Tuesday). Grabbed a 3A Battery Tender and plugged it in. Probably left it charge for less than 5 minutes, and the car starts right up.

That stated, I did notice something peculiar before I got it working. I used my ODBLink MX+ and noticed that it read the battery was 11.1V. I eventually get the panels off in the frunk and measured the voltage at the jump starting points... 11.9V. That's a pretty big difference. That's the difference between 50% SOC and basically dead. Could it just be as simple as a bad calibration or lookup table for the 12V battery voltage? Or maybe the sensor is temperature sensitive?

Going to call my local dealer and see what they can do.

@Ford Motor Company

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[Dhruval Shah]

So, I had the same issue as many others. I had the problem for a while, and it was a case of cold weather (sub 10 degrees F). Left the Mach E outside overnight and wouldn't start in the morning... eventually it warmed up and the car started fine. Drove it for a bit, and it stranded us at church on a relatively cold day after less than 3 hours (not a crazy long church... just had a lot of prep work before it). Eventually got it started and took it into the Ford dealer. They installed some software updates related to the screens not shutting off. Didn't see the issue again for a few weeks.

Then this Sunday, I got home left it in the driveway again, and it wouldn't start again Monday morning! Finally got time to look at it today (Tuesday). Grabbed a 3A Battery Tender and plugged it in. Probably left it charge for less than 5 minutes, and the car starts right up.

That stated, I did notice something peculiar before I got it working. I used my ODBLink MX+ and noticed that it read the battery was 11.1V. I eventually get the panels off in the frunk and measured the voltage at the jump starting points... 11.9V. That's a pretty big difference. That's the difference between 50% SOC and basically dead. Could it just be as simple as a bad calibration or lookup table for the 12V battery voltage? Or maybe the sensor is temperature sensitive?

Going to call my local dealer and see what they can do.

@Ford Motor Company

Please review other threads on the same issue. Mine has the same issue and possible fixes are mentioned under that.

 

[Ford Motor Company]

So, I had the same issue as many others. I had the problem for a while, and it was a case of cold weather (sub 10 degrees F). Left the Mach E outside overnight and wouldn't start in the morning... eventually it warmed up and the car started fine. Drove it for a bit, and it stranded us at church on a relatively cold day after less than 3 hours (not a crazy long church... just had a lot of prep work before it). Eventually got it started and took it into the Ford dealer. They installed some software updates related to the screens not shutting off. Didn't see the issue again for a few weeks.

Then this Sunday, I got home left it in the driveway again, and it wouldn't start again Monday morning! Finally got time to look at it today (Tuesday). Grabbed a 3A Battery Tender and plugged it in. Probably left it charge for less than 5 minutes, and the car starts right up.

That stated, I did notice something peculiar before I got it working. I used my ODBLink MX+ and noticed that it read the battery was 11.1V. I eventually get the panels off in the frunk and measured the voltage at the jump starting points... 11.9V. That's a pretty big difference. That's the difference between 50% SOC and basically dead. Could it just be as simple as a bad calibration or lookup table for the 12V battery voltage? Or maybe the sensor is temperature sensitive?

Going to call my local dealer and see what they can do.

@Ford Motor Company

Hi there! Can you send us a PM with your VIN and Ford dealership information? I’d be happy to look into this on my end.

 

[hawkeye3point1]

I used my ODBLink MX+ and noticed that it read the battery was 11.1V. I eventually get the panels off in the frunk and measured the voltage at the jump starting points... 11.9V. That's a pretty big difference. That's the difference between 50% SOC and basically dead. Could it just be as simple as a bad calibration or lookup table for the 12V battery voltage? Or maybe the sensor is temperature sensitive?

Could just be voltage drop between the LVB terminals and the module (used to be the ECU) where the OBD value is sensed. Can vary with wake state of the car.

Key-on voltage should be 15V. You have to check when the car is asleep to get a valid LVB health check, should be 12V or more.

I think you need to drive this car regularly in the cold to maintain the LVB. The MME will wake up the DC-DC converter to recharge the LVB if it gets low, but its best to not let it sit until that happens, especially if sulfation has occurred from production delays and transit time. And when that does occur, it is more like shock therapy than normal AGM charge sequence IMO.

 

[Joe Tennies]

So I had another data point after going around 3 or 4 miles to make sure it worked... no issues. Checked the values it read 12.3 and my multimeter read 12.4. a 0.1V difference seems like resistance of cable or uncalibrated multimeter, etc. Seems odd that a 0.5V difference at my multimeter changes the error bar from 0.1V to 0.8V.

And yes, I've seen the other posts. I took it in 2 weeks ago to get a bunch of SW updates. It happened again, and @DevSecOps is thinking that it might be something else.

While there's almost certainly some power drains that still need to be addressed, that still leaves the question of why the HVB isn't charging the LVB when needed. It's a redundant system. So, I've been a programmer for over 20 years with 15 of those being on embedded systems. I can tell you that the most common failure points that don't get fixed right away is are hardware/software integration or a calibration process one. Just taking a guess at how the system works, I expect there's a battery SoC that's "below this point, we should should charge", but there's also likely a safety one of "below this point that's lower than the charge one, we shouldn't charge the battery as it's unsafe to do so". I'm sure in all their simulations, or potentially even in one that is calibrated in the lab, this works correctly. My guess is either their calculation for the LVB battery voltage either has a bad curve (especially under cold conditions if temperature plays into the sensor) or there's missing/bad calibration data for values below a certain point. My guess is that the detection is going right from "it's fine/no need to charge" right to "it's dead, Jim" without hitting the "it should charge" in between.

The other possibility is that there's a software/software integration that's failing. I'm noticing that it's saying either the BECM or Hybrid PCM is sending invalid data (can't remember which). Perhaps one side isn't reading the values correctly and putting the system in some sort of lock down. While this might just be a bad unit, it seems odd to me that I could get it to go again w/ just a 3A 12V charger for a couple seconds and drive a couple miles w/o any of the warning lights turning on. I park, and it works fine next time I start it up a few hours later. That doesn't sound like a faulty hardware thing unless it's very intermittent (again a possibility, but I'd put it as less likely than an integration issue).

 

[Dhruval Shah]

So I had another data point after going around 3 or 4 miles to make sure it worked... no issues. Checked the values it read 12.3 and my multimeter read 12.4. a 0.1V difference seems like resistance of cable or uncalibrated multimeter, etc. Seems odd that a 0.5V difference at my multimeter changes the error bar from 0.1V to 0.8V.

And yes, I've seen the other posts. I took it in 2 weeks ago to get a bunch of SW updates. It happened again, and @DevSecOps is thinking that it might be something else.

While there's almost certainly some power drains that still need to be addressed, that still leaves the question of why the HVB isn't charging the LVB when needed. It's a redundant system. So, I've been a programmer for over 20 years with 15 of those being on embedded systems. I can tell you that the most common failure points that don't get fixed right away is are hardware/software integration or a calibration process one. Just taking a guess at how the system works, I expect there's a battery SoC that's "below this point, we should should charge", but there's also likely a safety one of "below this point that's lower than the charge one, we shouldn't charge the battery as it's unsafe to do so". I'm sure in all their simulations, or potentially even in one that is calibrated in the lab, this works correctly. My guess is either their calculation for the LVB battery voltage either has a bad curve (especially under cold conditions if temperature plays into the sensor) or there's missing/bad calibration data for values below a certain point. My guess is that the detection is going right from "it's fine/no need to charge" right to "it's dead, Jim" without hitting the "it should charge" in between.

The other possibility is that there's a software/software integration that's failing. I'm noticing that it's saying either the BECM or Hybrid PCM is sending invalid data (can't remember which). Perhaps one side isn't reading the values correctly and putting the system in some sort of lock down. While this might just be a bad unit, it seems odd to me that I could get it to go again w/ just a 3A 12V charger for a couple seconds and drive a couple miles w/o any of the warning lights turning on. I park, and it works fine next time I start it up a few hours later. That doesn't sound like a faulty hardware thing unless it's very intermittent (again a possibility, but I'd put it as less likely than an integration issue).

Mine has same issues starting in cold weather and is in dealership since a month for HVJB and BECM replacement. Hope it works. Lots of complains about this issue in colder regions.

 

[BigMach-E]

Well, I live in the Bay Area, California. I had the "stop safely now"/battery icon/stuck shifter/ "full accessory power active" brick thing happen. Jump did nothing. Towed into storage, going to local dealer tomorrow. I live in the most temperate locale in the US. This doesn't seem to be a weather thing. I will find out more tomorrow.

 

[Dhruval Shah]

I heard this issue only in cold weather till today. I also heard one from Florida having the issue and people are increasing everyday and Ford really needs to recognize the issue and atleast assure people if this will have a fix or not.

 

[Joe Tennies]

Okay, so I went to a friend's house from about noon to about 3:30pm on Sunday. The car was fine getting there, but the temperature dropped from 40s to about 20, and it wouldn't start again. It took 3 days to get it going again. It wouldn't start on the day it was 34. It did start on the day it got to 42.

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