tuna55
MegaDork
10/12/23 3:21 p.m.
It's a 2018 Pacifica. It's been okay, with hiccups along the way. The main battery was replaced in 2022. Tunawife got a start/stop unavailable message while driving the other day. While I don't care much about that feature, I know that a failing aux battery can drain the main battery, so I replaced it. It didn't fix it, and there are no codes to clear with my really crappy code reader.
Main battery open circuit voltage 12.9 (DMM)
Old aux battery open circuit voltage 12.7 (DMM)
New aux battery open circuit voltage 13.1 (DMM)
Main battery running voltage 14.4 (dash, I'm lazy)
I don't know how to load test either, really, with what little equipment I have for modern cars.
What's next?
tuna55
MegaDork
10/12/23 3:42 p.m.
lnlogauge said:
https://www.asburyauto.com/2018-chrysler-pacifica-battery-recall
Not having start/stop seems more like a perk to me.
No open recalls. I believe we may have had that one done anyway.
lnlogauge said:
https://www.asburyauto.com/2018-chrysler-pacifica-battery-recall
Not having start/stop seems more like a perk to me.
Eh. The Exploder has it, and when we bought it I thought it would drive me nuts. Now I barely notice it.
tuna55
MegaDork
10/12/23 4:25 p.m.
Not totally helpful to talk about if you like start/stop or not.
I am not familiar with the Chrysler setup specifically, but they all operate similar. If I am understanding correctly, this sounds like its something new that popped up so its safe to assume we are not talking HVAC settings, seat belts being latched, grade of the road at a stop, and all the other things that can mess with the feature. In that case I would bet a GRM sticker the problem is either related to battery state of health or state of charge. I don't know what their threshold is but some manufactures like to have the state of charge threshold for start/stop engagement *just* below what the alternator will charge to with city driving.
Some manufacturers have informational TSB with a lot of start/stop info in them. Might be worth looking into or asking your dealer. If it is SOH/SOC you will need to have it tested with a Midtronics tester or similar. Most dealer service advisors will do it for free with the handheld quick check unit they are supposed to use in the service lane. YMMV
Additional thought, if you have a battery charger, throw it on over night and see if Start/Stop works in the AM
mtn
MegaDork
10/12/23 4:46 p.m.
In reply to logdog (Forum Supporter) :
That sounds like a remarkably logical diagnosis, and one I never would have thought of.
Seems pretty common. This thread refers to a free dealer fix. Also something about the powertrain control module?
Consensus seems to be it's not a battery issue, but rather electronics.
https://www.reddit.com/r/ChryslerPacifica/comments/rgip7c/stopstart_unavailable_service_stopstart_system/?rdt=48554
Steve_Jones said:
tuna55 said:
Not totally helpful to talk about if you like start/stop or not.
You must be new here.
I LOL'ed. Tried to vote your comment up, but it didn't take.
1988RedT2 said:
Steve_Jones said:
tuna55 said:
Not totally helpful to talk about if you like start/stop or not.
You must be new here.
I LOL'ed. Tried to vote your comment up, but it didn't take.
It's because certain people downvote every comment I make, it must bring a little joy to an otherwise miserable existence. You just canceled one of their votes out.
tuna55
MegaDork
10/12/23 7:37 p.m.
logdog (Forum Supporter) said:
I am not familiar with the Chrysler setup specifically, but they all operate similar. If I am understanding correctly, this sounds like its something new that popped up so its safe to assume we are not talking HVAC settings, seat belts being latched, grade of the road at a stop, and all the other things that can mess with the feature. In that case I would bet a GRM sticker the problem is either related to battery state of health or state of charge. I don't know what their threshold is but some manufactures like to have the state of charge threshold for start/stop engagement *just* below what the alternator will charge to with city driving.
Some manufacturers have informational TSB with a lot of start/stop info in them. Might be worth looking into or asking your dealer. If it is SOH/SOC you will need to have it tested with a Midtronics tester or similar. Most dealer service advisors will do it for free with the handheld quick check unit they are supposed to use in the service lane. YMMV
No tsb and nothing I can find to condemn the 2022 big battery nor either the old or new aux battery.
I don't have time to deal with the dealer really.
In reply to tuna55 :
It's not my fault you're not getting laid, you're mad at the wrong person.
In reply to Steve_Jones :
He asked to stay on topic. I think people can be respectful enough to do that. Not sure what point you're trying to prove, but I wish you wouldn't.
Wish I wouldn't have shared my opinion on the stop start in the first place. Definitely wasn't trying to derail your post.
tuna55
MegaDork
10/12/23 8:32 p.m.
lnlogauge said:
In reply to Steve_Jones :
He asked to stay on topic. I think people can be respectful enough to do that. Not sure what point you're trying to prove, but I wish you wouldn't.
Wish I wouldn't have shared my opinion on the stop start in the first place. Definitely wasn't trying to derail your post.
Thanks
No worries, at least you provided something valuable as well. I didn't know there had been a TSB though my car doesn't seem to be affected or was already repaired. We did have some issue with grounds long long ago, and that may have been related. I really would like an answer to this thing, I don't believe it makes sense to be the health of either battery given than one is new and one is just a year old and they both seem to test fine. Granted I can't test them thoroughly. Life is really too busy to bring this thing to a dealer, my wife and I are always out in about dropping kids off every day so being without one car is a major hurdle, plus I've had really bad experiences with most dealers trying to diagnose things.
dps214
SuperDork
10/12/23 8:36 p.m.
Are you sure there's an actual problem? Those systems have like a hundred variables that all need to be in the right range for it to work. It's pretty common for functionality to be a bit inconsistent.
11GTCS
SuperDork
10/12/23 8:46 p.m.
dps214 said:
Are you sure there's an actual problem? Those systems have like a hundred variables that all need to be in the right range for it to work. It's pretty common for functionality to be a bit inconsistent.
This ^ If your wife made a number of stops doing errands without much run time between stops it's possible that the controller sensed the main battery charge state was getting low and automatically disabled the function.
My company car (Chevy) has start / stop, it won't automatically shut down at a traffic light or stop sign until I've driven 10 or so miles if I've been away on vacation and the car has been sitting. Climate control settings can also disable it as others have mentioned.
tuna55
MegaDork
10/12/23 9:02 p.m.
11GTCS said:
dps214 said:
Are you sure there's an actual problem? Those systems have like a hundred variables that all need to be in the right range for it to work. It's pretty common for functionality to be a bit inconsistent.
This ^ If your wife made a number of stops doing errands without much run time between stops it's possible that the controller sensed the main battery charge state was getting low and automatically disabled the function.
My company car (Chevy) has start / stop, it won't automatically shut down at a traffic light or stop sign until I've driven 10 or so miles if I've been away on vacation and the car has been sitting. Climate control settings can also disable it as others have mentioned.
Yes I'm sure. It's just turned over 107k and the only other time I've seen the light is when the main battery was dying.
Opti
SuperDork
10/12/23 9:13 p.m.
I just ran into this on a Pacifica. If you can get a better scanner they have pids for what is stopping it from being available. If I remember correctly there is not a reset for the battery logic module (can't remember what it's actually called) and it can't be told it has a new aux battery, and it can require sitting for 8 hours off up to 3 or 4 times before registering and coming online. If you just put the battery on, drive it gets it up to op temperature and just use it normally for 2 or 3 days and check back in.
Assuming you've already done that, borrow a scanner from someone and you should be able to see specifically why it's unavailable
Assuming it's the same setup as a Wrangler, disconnecting the - from the main battery, and only the main battery for 30 minutes, should reset it. Note the word "should".
tuna55
MegaDork
7/16/24 7:36 p.m.
Found the problem.
We brought the van to the dealer for three small issues since we're 5k left in the bumper to bumper warranty. One of the issues was the recirculation button flashing. They replaced the humidity sensor in the HVAC.
Start stop works now.
