conger

Which makes me question the design. Why does the TPMS need to come on when the vehicle is likely unoccupied? Doesn't it make more sense for it to perform its test once the engine is running and the vehicle is about to go into use?

3kushn

This is one reason I haven't pulled the ring. I don't know what else it does. For instance is this part of controlling the Alternator output? If so are we dumping too much amperage as in there's no amp drop to the battery when it should only be seeing 1 or 2.


Simply removing the message reminds me (no disrespect) of my wife's friend who put masking tape over the alternator idiot light cause it was annoying.


What other type of messages won't come through with the ring removed?
I don't have that answer. Wish I did.


As far as batteries dying my first one died even with daily use including 100's of 300 mile trips. The second one died while it sat for 10 days. Think I gotta leak somewhere?? Hmmmm Even so a 300 mile trip with only stopping to pee should charge the battery. At least to a safe level. At any rate all my other cars since 1970 charged up long before that if they ever got low. Well maybe the old "69" Kia had a few electrical issues.

JEMA

Well my first experience with a dead battery was two days after a 17 hour trip in the truck, stopping only for gas and fast food. Should have been completely charged after that trip. A day after that trip I did my normal driving routine and I noticed a low battery indication and a slow cranking that I thought was my imagination. Second day I tried to start the vehicle and the battery was completely drained down to 6 volts. Dealer charged it up, reset the BMS, tested the battery for load, tested the vehicle for draw, and said everything tested fine. They called into Ford and their only recommendation was to reset the BMS. Still driving it without a second episode (a few weeks now), but zero explanation on why it happened and zero confidence that it will not happen again. I am thinking the software got wrapped around itself due to something that happened during that trip. I did use the sync voice command a lot, I did use the sync Pandora app for the first time (which got hung up several times) during that long trip. With all the electronics and sensors, it could be anything, even down to opening and closing the doors quickly (as some other post suggested), long hours of driving (in reference to all the internal software timers to do things), or who knows what. I just hope there is an explanation (and a fix) soon.

conger

You don't disconnect it, you only remove the wire from inside so that it will not measure excess current draw. I have been operating like that for about 10 months now. My F150 has lots of bells and whistles and all systems are behaving as they should. Alternator out put is about 14.4 vdc and maintains under varying loads at idle and varying engine RPMs.
For the record, amperage. Can't be dumped like excess baggage. The alternator and battery will supply on an as needed basis.
I didn't decide to do this as a guess. I looked at the how the system gets it information about what it considers excess current draw from the battery and thought I would change the reference.
I've been playing with cars most of my life as a hobby and I'm a master electrician and also have background in electronics engineering technology.
By removing the battery wire from inside the sensor, you're just telling the ECU there is no problem. Only draw back is, if there is a problem, it won't tell you.

Clone

But, if there is a problem it will probably be dead anyway! Conger, since you removed the ring, have you played the radio at all with the truck not running and things of that nature? If so, have you ever had the battery give you a hard start? If the ring might be a piece of the problem, I may take mine off as well!

conger

My radio will play now for about 35 minutes before the BMS message shuts it off. My sync system and everything else works fine. But you DON'T disconnect the ring. You just remove the negative battery wire so that it doesn't not run through the center of the ring. This way the sensor will still be part of the system it just won't ever detect excess current being drawn from the battery. So we are just fooling the system into think everything is fine.

Please note that I do have a battery drain problem. Relocating the negative sensor ring only stops the BMS message. If I don't run my truck every 4 or 5 days, I will have a nearly dead battery.

3kushn

Conger, Like I said, no disrespect intended. I pay attention to what you write. Its been obvious you're on a different level than I am.
I'm more a thinker than a tinker. Gets me in trouble sometimes when I try tinkin.

OK with your experience above, assuming your alternator recharges the battery on day 5 and not a battery charger, and JEMA's 700 mile trip experience along with my frequent shorter but still long trips kinda verifies the software prevents a full charge should the battery drops below some threshold.

Wonder if that's a bug or intentional. Why, if intentional?

03ford4x4

I have also removed the ring from the negative battery cable a few months ago. I have had no message or charging problems. Let it sit for two weeks went out and started right up.

Sunny222

Been having the battery saver issue for a couple of weeks...There's a brand new SSM 44750 (issued Oct. 6,2014) .... they reprogram the body control module (BCM)...see if it fixes the problem...just over 8000 km (5000 mi.).

Larsen00

Dunno. That's the way they drew it up. It would seem to me a key on check would be best but engineers live in an altered state of reality so there's no telling why they think it needs to be done this way.