Although our 2014 SD4 doesnt have stop/start, it does have a Battery Monitoring System (BMS). I think this is a feature of it being a late model.

How do you reset the BMS ?

I know how to do it for Fords like my Fiesta:
1. Turn on ignition (not engine)
2. Ensure headlights are set to on
3. flash the high beam five times
4. press the brake pedal 3 times
5. wait for the battery light to flash on the dash.
6. Turn off then restart.

But this doesnt seem to work for my other Ford, the FL2  Jules

Last edited by jules on 21st Mar 2024 8:55 am. Edited 1 time in total

Guessing this Jaguar BMS reset via SDD will be same/similar for FL2:

 Current: FL2 64 plate Black SD4 Auto Metropolis
Gone: FL2 2006 Tambora Flame Orange 2.2 TD4 manual HSE - (90K KM - 268K KM, LHD in CH)

I was hoping there was a DIY method without SDD, but it seems not. Jules

My Autel AP200 and no doubt others readers will reset the BMS.

I simply have four x 26AH gel batteries for fridge & jump starting if necessary. Jump started too many other cars! Also handy to run the 3 compressors, either for cleaning the car or around the home. 360 amps for five minutes or 1040 amps briefly. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

I need to rephrase my question.

So:
Is there a way to reset the BMS without the use of additional diagnostic hardware/software ? For example, using a combination of DIY switch and peddle presses ?


My investigations so far indicate that there is not. Jules

I'm sure you're well aware of this Jules and I know this isn't resetting, more recalibrating but just in case.

"If a new battery is fitted to the vehicle, the BMS (battery monitoring system) module will require recalibrating to register the greater charge holding capacity of the battery, this is performed using Land Rover approved diagnostic equipment. If diagnostic equipment is not available the BMS module will recalibrate automatically however, this could take 48 hours to complete depending on vehicle usage."

I know I've said this in your other thread so probably sound like a broken record . But would a hard reset cause the BMS to loose it's data and therefor causing a reset? Or is the BMS data actually stored somewhere?
With the BMS mounted on the negative terminal, I'm guessing it's not as easy as finding a plug to unplug it, maybe go for a drive and then plug it back in somehow?  https://www.youtube.com/@scottandalana4x4

I have found that each time, after installing a new battery, the Battery Management System relearns, over the next few days/journeys, the new increased (normal) Battery Capacity.
For example, I noticed that the radio stayed on longer when the engine was off.

I believe that most systems in the FL2 learn as they go along. FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 76k+ miles) (MY2015)

I would think that doing a hard battery reset as well as touching the polarities should reset the BMS. I did mine with SDD when I switched to an AGM battery the first time but I replaced my AGM (bluetooth module I had to eventually loop bypass) last year and did not reset the BMS. As noted, 48 hours and it should start a new cycle.

Dean1234 wrote:

I'm sure you're well aware of this Jules and I know this isn't resetting, more recalibrating but just in case.

"If a new battery is fitted to the vehicle, the BMS (battery monitoring system) module will require recalibrating to register the greater charge holding capacity of the battery, this is performed using Land Rover approved diagnostic equipment. If diagnostic equipment is not available the BMS module will recalibrate automatically however, this could take 48 hours to complete depending on vehicle usage."

I know I've said this in your other thread so probably sound like a broken record . But would a hard reset cause the BMS to loose it's data and therefor causing a reset? Or is the BMS data actually stored somewhere?
With the BMS mounted on the negative terminal, I'm guessing it's not as easy as finding a plug to unplug it, maybe go for a drive and then plug it back in somehow?

Or is it possible to disconnect the BMS to stop the warnings ?- I dont need it as my car doesnt have stop/start as its an SD4 with an autobox. Jules

What is the voltage when the engine is running. My car is 14.4 volts at the battery with typically 50 amps charging according to clamp meter. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

Here is the voltage across the battery, taken a few mins ago - showing a quick start / stop of the engine.
Getting around 14.9v whilst engine running.




No idea what the current is. Jules

As it turns out the car has stopped giving low battery warnings, well for the time being anyway.
I guess as our FL2 is only getting used once or twice a week at the moment, it took ages for enough start/stop cycles to accumulate for the BMS to detect (via some algorithm I suppose) that a new battery had been installed.

Another thing I came across in my searching about the BMS is that if the charger is connected directly to the battery NEG terminal then the BMS cannot register the charge being delivered.
So the charger's NEG connector should be placed on the far side of the BMS sensor eg on a ground connection, and not onto the battery NEG terminal, so that the battery and BMS are within the chargers two connections.
Does that make sense to those that know how the BMS actually works ? Jules

Makes total sense to me. When I run SDD, and I haven't in a while, I connect red to +ve battery terminal and -ve to an engine "hook" on my i6. If you charge on board the battery, this method also work quite well.

And, glad the light is gone!