Strange issues

[Davexxxx]

Does this work on the BS?



Its what I did to my truck, immediately after a full charge, directly to the posts and it disappeared a bunch of gremlins. Like magic.

Sponsored

 

[cprcubed]

From Dude's post in another thread: Major electrical issues. | 2021+ Ford Bronco Sport Forum - Broncosportforum.com

Battery Sensor Reset (Battery Management System (BMS) Reset):
When you install a new battery, reset the battery sensor by doing the following:
1. Switch ignition on, and leave the engine off.
Note: Complete Steps 2 & 3 within 10 seconds.
2. Flash the high beam headlamps five times, ending with the high beams off.
3. Press and release the brake pedal 3 times.
The battery warning lamp flashes 3 times to confirm that the reset is successful.

Cheers!

 

[wireman]

When you replaced the battery do you do the reset? If not the system may be falsely reporting battery issues based on time and use.

Battery was replaced under warranty by the dealer.

 

[Mark S.]

When you charged the battery did you connect the negative lead to the battery post, or to the grounding point on the fender? I'm pretty sure the BMS sensor is between the negative post and the vehicle electrical system. If you connect directly to the negative post the BMS will not "see" that you've added charge to the battery. More here:

 

[Davexxxx]

When you charged the battery did you connect the negative lead to the battery post, or to the grounding point on the fender? I'm pretty sure the BMS sensor is between the negative post and the vehicle electrical system. If you connect directly to the negative post the BMS will not "see" that you've added charge to the battery. More here:

If the BMS miscommunication is the culprit, as it was on mine and may be for the OP, charging through the BMS won't work. I tried that.

You have to charge directly to the batt posts until full, then immediately reset.

 

[Mark S.]

If the BMS miscommunication is the culprit, as it was on mine and may be for the OP, charging through the BMS won't work. I tried that.

You have to charge directly to the batt posts until full, then immediately reset.

Charging as described in the video works on my Badlands. Eliminates the low battery warning and restores auto start/stop function.

 

[Davexxxx]

Charging as described in the video works on my Badlands. Eliminates the low battery warning and restores auto start/stop function.

It worked on my truck for a few days too but the only thing that made the issues stay gone, was doing it exactly as I described.

Several others have tried it and it worked for them as well. Some, said it worked but was only temporary. None have noted a downside.

YMMV

 

[wireman]

When you charged the battery did you connect the negative lead to the battery post, or to the grounding point on the fender? I'm pretty sure the BMS sensor is between the negative post and the vehicle electrical system. If you connect directly to the negative post the BMS will not "see" that you've added charge to the battery. More here:

Mark, between the + on the battery and the fender grounding post.

 

[Davexxxx]

Mark, between the + on the battery and the fender grounding post.

That would still be incorporating the BMS in the loop.

 

[Mark S.]

Mark, between the + on the battery and the fender grounding post.

Yup, that would be the way Ford recommends. Perhaps you should try Dave's method.

 

[R W NORRIS New Mexico]

I don't know if this is right or wrong, but here it goes. Make sure you hook up the cables according to the owners manual, meaning in the right order. Place the Hot cable on the battery first, then hook up the Ground cable. Once completed, follow the Battery Management steps in the manual. Make sure when you do, to Shut the door. The reset tells the computer that you now have a new battery and how to charge it. New takes less charge than an old battery. Now keep in mind the Computers must "relearn" everything. For example, did you loose your radio settings? They make a simple 9 volt OBD II unit that will keep all your computer settings next time you disconnect the battery for more than 30 minutes. Such things as memory for "Auto" on the heat and AC, Radio Settings, the way you "normally" drive with Brake action or Gas peddle position when you take off. It also shows the Start Stop when you need it. In the event that you don't use the "Backup Power", the computer must relearn and that takes about 500 miles of driving. Keep in mind, if you hook up the Ground Cable first, like we used to do, it will detect the Positive cable voltage as a surge and protect the computer. It will reset everything to re-learn. Sounds stupid but I had the "Gremlins" from "cleaning" my cables and posts when I took a phone call and did not have the backup cable hooked up. They are on 12-20 bucks on Amazon and I keep mined hooked under the Battery Hold Down as a reminder to connect it if I mess with the battery. I hope this helps with your problem. There is a complete procedure listed in the owners manual for Battery replacement, and it requires you to "turn on the ignition" and wait for 5 minutes for everything to shut down before disconnecting the battery. Shut the doors so the interior light turn off as well. Good Luck. Rodger

 

[wireman]

I don't know if this is right or wrong, but here it goes. Make sure you hook up the cables according to the owners manual, meaning in the right order. Place the Hot cable on the battery first, then hook up the Ground cable. Once completed, follow the Battery Management steps in the manual. Make sure when you do, to Shut the door. The reset tells the computer that you now have a new battery and how to charge it. New takes less charge than an old battery. Now keep in mind the Computers must "relearn" everything. For example, did you loose your radio settings? They make a simple 9 volt OBD II unit that will keep all your computer settings next time you disconnect the battery for more than 30 minutes. Such things as memory for "Auto" on the heat and AC, Radio Settings, the way you "normally" drive with Brake action or Gas peddle position when you take off. It also shows the Start Stop when you need it. In the event that you don't use the "Backup Power", the computer must relearn and that takes about 500 miles of driving. Keep in mind, if you hook up the Ground Cable first, like we used to do, it will detect the Positive cable voltage as a surge and protect the computer. It will reset everything to re-learn. Sounds stupid but I had the "Gremlins" from "cleaning" my cables and posts when I took a phone call and did not have the backup cable hooked up. They are on 12-20 bucks on Amazon and I keep mined hooked under the Battery Hold Down as a reminder to connect it if I mess with the battery. I hope this helps with your problem. There is a complete procedure listed in the owners manual for Battery replacement, and it requires you to "turn on the ignition" and wait for 5 minutes for everything to shut down before disconnecting the battery. Shut the doors so the interior light turn off as well. Good Luck. Rodger

Always do + first, ground to fender 2nd. Thanks for the info.

 

[wireman]

Follow up on the battery issue. Checked the voltage this morning 18 hours after full charge and being driven yesterday.
Message again on the center screen and passenger door lock/unlock sensor not working.

DVOM read 12.1 volts, which for an AGM is approx. 50% SOC.

Hooked up my battery charger which showed 49% SOC.

Charged for 1 hour to 100% showing 12.64 volts.

Started vehicle and shut off, no message on screen and passenger door sensor worked.
Waited 15 minutes. Voltage now at 12.48 volts.

Message on center screen returned and the pass. door sensor not working again.

I don't want to reset the BMS yet because the battery is still under warranty and if the dealer hooks up Forscan the actual days of service won't show accurately from when it was installed.
Right or wrong?

I'm leaning toward a bad battery, but I guess it could be an excessive parasitic draw.

I'm going to check with my service advisor about the battery warranty.

With this being a Motorcraft( Chinese made) I don't know if the recall will come into play because it's a second battery.

 

[Davexxxx]

I don't want to reset the BMS yet because the battery is still under warranty and if the dealer hooks up Forscan the actual days of service won't show accurately from when it was installed.
Right or wrong?

This is correct and no one should do anything they aren't comfortable with.

 

[sajohnson]

Today I charged the battery to 100% and 12.8 volts. Drove about 20 miles and back home. I shut it off, let it go to sleep, and turned the ignition on and the message was back.

This was 4 hours later. Battery voltage was at 12.2 volts. With an AGM battery 12.2 volts is about 60% S.O.C. So, 4 hours later it went from 100% to 60%.

If I am reading Wireman's post correctly, the problem has nothing to do with the BMS. Either the battery is faulty or there is a phantom load draining it.

Measuring the current flow out of the battery with everything off would be helpful.

Sponsored