GEN 2 Battery Monitoring System and Auto Stop/Start

[Larry Jeffords]

As much as some night think the Auto Stop/Start NOT working is a good thing, I'm a firm believer that all components of my Raptor should function as they are designed regardless of the inconvenience they may cause.

I have a 2018 screw. Awesome vehicle. It was in the shop in February for several days to finally resolve the freezing door lock issue. I noticed a short time later that the auto stop/start was not working and the message on the console said "due to vehicle charging". Not a big deal so I just let it go. About a month ago, I took it in for an oil change and asked them to take a look at it. The tech spent close to six hours troubleshooting, fully discharging and recharging the battery and still it wouldn't work.

When he came out to chat with me about it, I reminded him that the vehicle sat for several days while the locks were being repaired and that seemed to be when the problem began. His face lit up and he went back to the shop. About five minutes later he returned and was happy to report that the problem was resolved with a simple reset of the Battery Monitoring System (BMS).

My Raptor is not my daily driver and it is not uncommon for it to sit in the driveway for several days. I took her for a run yesterday and sure enough, the Auto Stop/Start is not working again "due to vehicle charging". It hadn't been started for 3 or 4 days so I'm assuming I need to reset the BMS again. Does anyone know if it can be done without taking it to the dealer every time? I'm sure they won't charge me (my dealer is the best) but it would be a pain in the ass to have to take it in each time.

 

[Terry]

I don't know about resetting the BMS but it does sound like the battery isn't being fully charged. Alternators are better battery maintainers than chargers. Put the truck on a smart charger and let it fully charge the battery. A good charger will tell you when the battery is fully charged and will then maintain the charge indefinitely. Once the battery is fully charged take it for a spin and see if start/stop is working properly. I suspect that it will. Fully discharging a battery degrades it and decreases it's useful life. I'd put the charger or a battery tender on the battery anytime it's going to set for more than a week just ensure you get the best service and longevity out of the battery. Raptors have AGM batteries from the factory so be sure to set the charger to recharge an AGM battery.

 

[Gdog]

Does anyone know if the BMS needs to be reset by the dealer or is it something we can rest ourselves?

 

[realjones88]

I think you have the opposite problem...your BMS is not charging the battery enough.

Check out this thread where people wanted to disable the BMS...their trucks went from to 80% charge to nearly 100%. In other words disabling the BMS caused the battery to charge more completely.
https://www.f150forum.com/f118/2018-2019-f150-auto-start-stop-mess-fix-425608/index15/#post5914838

Obviously if you want start/stop to work don't disable the BMS. How long are you driving the truck for? Start/stop is not going to instantly come on if the truck has been sitting for days.

You can reset the BMS yourself in Forscan.

 

[Larry Jeffords]

I successfully did some mods with ForScan shortly after I got the truck. I would have to re-educate myself as to how to use it again but would be willing to do so. Anyone have a step by step? I have the spreadsheet but but I'm not finding "RESET BMS".

 

[Larry Jeffords]

Missed your question. Vehicle was not started for 3 or 4 days. I had a 40 minute highway run yesterday and it still wasn't working "due to vehicle charging".

 

[Just_in_time]

From what I found - it is not recommended to reset the BMS unless you are installing a new battery.
============================
NOTICE: DO NOT reset the battery monitoring system using the diagnostic scan tool. This reset is reserved for new battery installation. Resetting the battery monitoring system will clear the learned battery data, the battery time in service, and will affect the aging algorithm parameters, which have been learned since the installation of the battery.

Battery Replacement

If the vehicle battery is replaced, it is very important to perform the BMS Reset using a diagnostic scan tool. If the battery monitoring system reset is not carried out, it holds the old battery parameters and time in service counter in memory. Additionally it tells the system the battery is in an aged state and may limit the Electrical Energy Management system functions. For more information,
Refer to: See: Battery > Components > System Operation and Component Description Battery and Cables - System Operation and Component Description (414-01 Battery, Mounting and Cables, Description and Operation).

 

[Larry Jeffords]

From what I found - it is not recommended to reset the BMS unless you are installing a new battery.
============================
NOTICE: DO NOT reset the battery monitoring system using the diagnostic scan tool. This reset is reserved for new battery installation. Resetting the battery monitoring system will clear the learned battery data, the battery time in service, and will affect the aging algorithm parameters, which have been learned since the installation of the battery.

Battery Replacement

If the vehicle battery is replaced, it is very important to perform the BMS Reset using a diagnostic scan tool. If the battery monitoring system reset is not carried out, it holds the old battery parameters and time in service counter in memory. Additionally it tells the system the battery is in an aged state and may limit the Electrical Energy Management system functions. For more information,
Refer to: See: Battery > Components > System Operation and Component Description Battery and Cables - System Operation and Component Description (414-01 Battery, Mounting and Cables, Description and Operation).

Excellent information - Thank you. This is what the forums are for.

 

[realjones88]

From what I found - it is not recommended to reset the BMS unless you are installing a new battery.
============================
NOTICE: DO NOT reset the battery monitoring system using the diagnostic scan tool. This reset is reserved for new battery installation.

...I'd bet dollars to donuts that's exactly what the tech did at the dealership though...

Try this for resetting BMS in Forscan. A few buttons to click it looks like.

 

[Larry Jeffords]

...I'd bet dollars to donuts that's exactly what the tech did at the dealership though...

Try this for resetting BMS in Forscan. A few buttons to click it looks like.

Thank you so much.