Auto Stop/Start Not Working

[grumpyunk]

This was after sitting for an hour. I made sure to not open any doors, unlock, etc. The hood was already open. Anyone know if this is normal?

Watch PHAD check a Linky for battery going dead...


I think his number was 6ma when fully sleeping. You are at 160ma, which personal opinion is a bit too much.
Ivan went through the networks on the Lincoln, essentially an Escape touted up, and then found which was going active, and found the guilty party.

My take on Mavericks is their BMS leaves something to be desired. It refused to charge my battery after a thousand mile round trip, only charging to the point that AutoSS only worked a couple times at either end after driving 500 miles. Manually applying a battery charger brought the charge up enough to work for a while.
A reset of the BMS seemed to help for a while, but AutoSS is still iffy. I have no idea how to check it.
tom

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[Bn1970]

confirmed to work.
BMS manual reset (5x flash, 3x brake) got stop-start working again immediately. truck is 1 yr old, with 45 K km's/28 K miles. don't have the time/patience to take in to dealer for battery test.

lasted 3 days, had to do BMS reset again. hopefully they come out with a TSB on this, I am definitely not going to waste my time with the dealership. (can tell by cranking speed, battery is very healthy.)

 

[bgn]

BMS was reset once by me, once by the dealership over two months. System is back to not working. "Engine on due to vehicle charging" or similar message on the screen status for the system all the time...

 

[grumpyunk]

BMS was reset once by me, once by the dealership over two months. System is back to not working. "Engine on due to vehicle charging" or similar message on the screen status for the system all the time...

Been there done that - seems to apply. As a non-engineer, there is a problem with the BMS on more than one Maverick. As I posted a while ago on this thread and another, driving 500 miles with a couple pit stops, on a slightly discharged battery resulted in a slightly more charged battery. It was not charged to full in a 500 mile trip. After a second return trip with a couple pit stops, the AutoSS was functional for perhaps two stoplights. And then it did not work any more.
The BMS makes sure the battery has sufficient charge for starting by disabling the system, but does not allow the charging system to recharge a battery even on long run cycles.
There is something wrong in the settings that determines the charge rate to be used, and I would say that it is set to 'lazy', letting the alternator loaf for most of the run time. It will NOT recharge a battey to full voltage.
That is a problem.
Likely taking it to a dealer will result in 'all systems normal, no problem found', which is absolutely true. It will pass any test given, but it will not charge a slightly discharged battery.
It is working as DESIGNED, but it is not effective. The LAZY charge setting embedded will allow fuel economy to be a little better as it assumes: 1)AutoSS works, and 2)the charge system won't have to work hard when driving, both of which would increase CAFE results.
Is this another VW diesel scam?

 

[oreomuffin]

Update: After over 3 weeks in the shop I might have some answers. You can see my other post here. The tech thinks that the faulty differential might have been the issue. The control unit was power cycling even when the truck wasn't on and thus draining the battery. We'll see after a few weeks if the system functions normally.

 

[jc888888888]

Bad battery not holding charge it seems?

 

[MakinDoForNow]

Bad battery not holding charge it seems?

There are many things that will "Turn Off" Auto ss, one of which is if sensors reveal to the computer that Dew Point is likely to be reached the computer will turn on auto defrost which will activate the AC condenser which will turn off the Auto ss.

 

[Mikeysd]

I just had my first oil change and the 10k checkup and I get my truck back and it feels like the idle is a bit high and the Auto Start/Stop is not working. I have it schedule to go back in Tuesday.

 

[Bill Quattlebaum]

I wish my start-stop would quit working. I do understand your frustration! Sounds like the battery must be the culprit. I wish car makers would quit making stop-start mandatory on new vehicles. It is very aggravating to me.

 

[Jah.]

Used start/stop until noticed battery issues . about 2-3 months . always turn off each time since then . not a fan .

 

[HeyBales]

They replace mine for this problem. Within a week it was doing the same thing. I took it back they said the battery was fine they charged it. I took it home and tested it the battery tests bad. The software is designed to only charge that battery between 60 and 70%. Therefore it never gets a full charge. The battery sulfates within days. That's a big problem. I will be taking mine back for the fourth time! Not happy

Within a week - no you have a different issue than normal poor charging range.
And of course different than this thread of EB battery issues.

Sadly they are probably going to throw your issue into the bin with another one and not troubleshoot it down to root cause.

That's why their test starts with a complete recharge, then load test. To see if battery damaged by going so low. They should also start with disconnecting the battery for computer reset - have you had to reset your radio stations or other settings?
If battery stays above what seems to be 39% SOH that other posters report - they call it good enough to start a hybrid. And for awhile it is.
Until it isn't.

Is your state Lemon Law for 3 of the same issue?
You'll need to get to that 3rd replacement battery then.

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