Ford BMS issues, research, testing, and solution results

[Snakebitten]

No incentive except to get a new one for a couple of bucks?

And you are right, in that my Battery Management woes are behind me and have been since swapping the aux AGM for the LFP.

My truck sat for 12 days before I got in it this morning. The static voltage was 12.78V as a result of multiple door opening and tailgate down/up events over those 12 days. The Ford SOC PID said 92% on startup.

By the time I got to the office it was 97% with me running the fan5 procedure for about 20 miles.

I don't think I have a malfunctioning shunt/sensor.
But I still am curious if I will see any changes if I replace it with a new version?

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[SilverPigeon]

...but I'd still get the revised version to have on hand just in case...

Rang local Ford dealer, can get in a few days for AUD$191.18!!!!!
Ordered a confirmed April'24 build BMS new from eBay; a few weeks from the US for $AUD68.28 ; can't wait to test results

 

[SilverPigeon]

...But I still am curious if I will see any changes if I replace it with a new version?

Curiosity hasn't killed my cat yet, only my wallet

 

[ReverendQ]

Rang local Ford dealer, can get in a few days for AUD$191.18!!!!!
Ordered a confirmed April'24 build BMS new from eBay; a few weeks from the US for $AUD68.28 ; can't wait to test results

Ouch, only $21 in SoCal @SilverPigeon , next time let me know to send you one I can get it to Sydney with other stuff I send to the office there.

 

[SilverPigeon]

...next time let me know to send you one I can get it to Sydney with other stuff I send to the office there.

Thanks Kevin, I'll try to remember

 

[Jmitchelltfo]

Awesome info!

Wouldn't it be nice if all the dealers were this well informed!

 

[Porpoise Hork]

Rang local Ford dealer, can get in a few days for AUD$191.18!!!!!
Ordered a confirmed April'24 build BMS new from eBay; a few weeks from the US for $AUD68.28 ; can't wait to test results

It's crazy how much of a markup dealers have, and that's on top of the higher prices you guys already day for imported goods.

 

[Snippy]

After replacing the BMS and doing the BMS reset procedure is it required to immediately let the truck stay off for 6-8 hours so it can get a proper SOC, or is it ok to drive it immediately afterwards?

 

[Davexxxx]

After replacing the BMS and doing the BMS reset procedure is it required to immediately let the truck stay off for 6-8 hours so it can get a proper SOC, or is it ok to drive it immediately afterwards?

The BMS reset does that.

BTW, after more than a yr. of doing the bench charge / BMS reset, I finally started getting warnings again. "Systems off to preserve battery" or some such.

Put the charger on, directly to the posts, wait until float, reset the BMS and expect to be good for another yr.

 

[FirstFord]

A data point, perhaps?

Some time ago, I too made changes in FORScan to try to increase the charge level. However, I wasn't sure quite where to go (using Livingitup's spreadsheet), so I used the so-called "Easy Method". Now that you have identified the address, I decided to revisit the values and compare them to the original OEM values that I had as a backup. Only one value changed:

726-08-02:
Factory OEM:
0007-0805-00
Changed to:
0007-0805-A0

726-08-02xxxxxx****-- In the above example from Jeff, the actual hexadecimal value we are seeing is 05A0. Target SOC% is defined with a range up to 200%

If we look more closely at the definition:
TargetSOC_Cfg (TSOCC) • % = Hex2Dec(****) /16 • Range: 0 - 200
we see it's not just a matter of converting hexadecimal (hex) to decimal (dec). What it says is:
"take the four-digit hex number, convert it to decimal and divide by 16"
'Therefore, 05A0 -> 1,440/16 =90.

The factory SOC is 80%. That's why the value is 80*16 =1,280 -> 0500 hex.
My setting of 120% is 120*16=1,920 -> 0780 hex.

Whoops! It appears that I may have unintentionally / inadvertently supplied some bad information. For the sake of speed and simplicity, I reasoned that I would compare the ASBUILT values of the original OEM backup to that of a more recent backup, and note the differences. Seemed fair enough.... But now I realize that there were a few assumptions packed in with that thinking.

I keep a spreadsheet "log" of any and all changes made through FORScan, and I record the existing values before the change, as well as the change itself (in effect, it is somewhat of a secondary backup). I reviewed my log, and the values don't jibe with what I posted earlier. I know that OTA updates (obviously) can change ASBUILT values. It appears that somewhere along the way, an OTA changed the original ASBUILT values for the BCM 726-08-02 address (the values that were in my original backup), but prior to my effort to change it. When I went to increase the charge rate in FORScan, I recorded in my log that the values were:

726-08-02

0007

0805

A4EB

Which is different from what I had in my original backup, thus the conclusion that it was changed by an OTA.
After attempting to increase the charge rate (using the "Easy Mehod"), I apparently went back and noted the new values where the 4 was changed to 0 (A0EB, which was also reflected in a more recent backup). I'm hoping to be able to get the laptop plugged in the next couple of days and reconfirm.

 

[Snippy]

Anyone else not able to reset the BMS with the headlight and brake pedal method? I made sure to follow all the steps and I don’t see any battery icon flashing. I don’t even see a battery icon on my dash period. 2022 302A with the normal dash (not 12” dash) if that helps.

 

[JohnTrigger]

Snippy, some have had it work fine after not working, if they give it several hours of “rest” and tried again in the AM.

 

[FirstFord]

Just had a wild-hare thought...

There is a BCM update that cannot be handled through FDRS anymore; it requires a dealership license.

How will replacing / updating(?) this module affect that? Will the module now be "updated"?

 

[SilverPigeon]

Anyone else not able to reset the BMS with the headlight and brake pedal method? I made sure to follow all the steps and I don’t see any battery icon flashing. I don’t even see a battery icon on my dash period. 2022 302A with the normal dash (not 12” dash) if that helps.

Are you trying to do this with the engine running? If so, the battery light will stay out if all is well.

The BMS reset procedure needs to be done with ignition on, engine off. Then you will see the battery light, and it flashing when the procedure is successful.

 

[SilverPigeon]

Just had a wild-hare thought...

There is a BCM update that cannot be handled through FDRS anymore; it requires a dealership license.

How will replacing / updating(?) this module affect that? Will the module now be "updated"?

If the ford servers have that update as the level of software that should be in the BCM, replacing the BCM and doing a PMI may put that software level into the BCM. In this case, it will disappear from the list of updates in FDRS (unless, like the ACM update, it refuses to disappear even though it's successfully done). Rather a costly way to try it

If the dealer performs this software update using their NASTF login, then it will disappear from the list of updates upon successful completion (unless, like the ACM update, it refuses to disappear even though it's successfully done).

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