Auto start/stop never ready

[ShadowsPapa]

It's about 14 when driving. 12.3ish sitting. I may have to end up taking it to the dealer if I can't figure out

You've gotten some good responses so far from several others and it sounds like you've covered those things now..........
For me, seeing those numbers of 14 while driving (not bad, but could be higher for a battery that's not fully charged)
12.3 is low enough that the auto stop/start isn't going to work. On the trucks I've measured, it appears to be 12.4 before it's satisfied that the batteries are high enough to trigger ESS.
If you can, if you have a charger that will charge AGM batteries properly (the batteries in modern Jeeps are AGM battery types) then put a charger on for a few hours and see if they come up.
I have a feeling with the numbers you gave here that you may be looking at needing the batteries fully charged then load tested. You can't do a proper load test with a voltage of 12.3. If I recall correctly from the documentation the dealers go by for testing, it's got to be at least 12.4 or higher before they can properly test the batteries.

Batteries can start a truck but still be of diminished capacity. That means they are fine as long as things are working and the truck starts - but they can't maintain that type of load. They can sprint but can't handle a marathon. The IBS (Intelligent Battery Sensor) on the negative terminal of the main battery tracks such things as best it can. Over time, depending on how this truck was used in the past, the batteries may have lost capacity due to sitting, lack of use, lack of being kept fully charged, a lot of "cycles", etc.

Sponsored

 

[Jackpaul]

Hello everyone. So I bought a 2021 Sport S with 20k miles on it and the auto start/stop has not worked once since I bought it. Whether I want it to or not is a different thing but it bothers me that I don't have the option. It always says not ready on the dash. Sometimes it'll say the reason but for the most part it just says not ready. I'm wondering if the previous owner had disabled it somehow and how I could enable it again if so. I haven't got a tazer yet but I don't know if he had one and used that to disable it and now that it's gone it's still disabled? Is there a harness I should look for for a disabler? It also never chimes when the seatbelt is unbuckled so I'm sure that was done with a tazer so maybe a tazer will allow me to enable it again? Any help would be appreciated. Thanks.

Have not read everyone’s comments, but it is likely the aux battery. Don’t get hung up on testing the battery, if it’s a 21 it’s the aux battery, change it.

 

[ShadowsPapa]

Have not read everyone’s comments, but it is likely the aux battery. Don’t get hung up on testing the battery, if it’s a 21 it’s the aux battery, change it.

LOL - seriously??
That's some of the worst possible advice because we have proven here that it's NOT likely the aux battery - others have found out by replacing it only to find the main battery was the culprit.
And he could replace batteries only to find it's another issue, or the IBS simply needs to be reset.
Sounds like fakebook responses to "why won't my battery charge" and you see everything from replace the battery to replace the belt to it could be a loose ground on the dash.
Pretty sad, IMO. Techs and electric experts try to help and he gets "just go spend some money, don't try to figure it out".

Flame away - but that's some of the very worst advice possible. Don't be smart, just start replacing parts even though there's no evidence or backing.
And maybe - he wants to learn about his truck and do things right.

 

[Jackpaul]

LOL - seriously??
That's some of the worst possible advice because we have proven here that it's NOT likely the aux battery - others have found out by replacing it only to find the main battery was the culprit.
And he could replace batteries only to find it's another issue, or the IBS simply needs to be reset.
Sounds like fakebook responses to "why won't my battery charge" and you see everything from replace the battery to replace the belt to it could be a loose ground on the dash.
Pretty sad, IMO. Techs and electric experts try to help and he gets "just go spend some money, don't try to figure it out".

Flame away - but that's some of the very worst advice possible. Don't be smart, just start replacing parts even though there's no evidence or backing.
And maybe - he wants to learn about his truck and do things right.

Haha ok, I mean do all the chasing ruling out “proven” things, yet even you state “not likely “ which means you know it’s possible. Then change the aux battery and remember I suggested it. I would do both batteries at the same time though…
You still suck

 

[Jackpaul]

Hello everyone. So I bought a 2021 Sport S with 20k miles on it and the auto start/stop has not worked once since I bought it. Whether I want it to or not is a different thing but it bothers me that I don't have the option. It always says not ready on the dash. Sometimes it'll say the reason but for the most part it just says not ready. I'm wondering if the previous owner had disabled it somehow and how I could enable it again if so. I haven't got a tazer yet but I don't know if he had one and used that to disable it and now that it's gone it's still disabled? Is there a harness I should look for for a disabler? It also never chimes when the seatbelt is unbuckled so I'm sure that was done with a tazer so maybe a tazer will allow me to enable it again? Any help would be appreciated. Thanks.
[/QUOTE]

Seriously though, Maybe @ShadowsPapa can explain the correlation of your driver side seat belt chime not working and the auto start/stop not functioning and not throwing a dashboard warning light, as well as the role of the aux battery in that…I would, but I don’t have Facebook to validate my opinion.

Regardless, most of the banter is well intended. sort through the bs and there is good advice.

 

[BringTheLightnin]

Voltages on and off. Drove 3 hours on highway yesterday and no start/stop ever. Always says not ready. No reason. Might take to dealer to check battery. Will reset the ESS today when I get home by unplugging the harness and reattaching. Tried everything else

 

[Hootbro]

12.2 VDC at rest, one or both of the batteries is getting tired. Like mentioned, most likely the AUX battery.

 

[Sdsteph]

Hello everyone. So I bought a 2021 Sport S with 20k miles on it and the auto start/stop has not worked once since I bought it. Whether I want it to or not is a different thing but it bothers me that I don't have the option. It always says not ready on the dash. Sometimes it'll say the reason but for the most part it just says not ready. I'm wondering if the previous owner had disabled it somehow and how I could enable it again if so. I haven't got a tazer yet but I don't know if he had one and used that to disable it and now that it's gone it's still disabled? Is there a harness I should look for for a disabler? It also never chimes when the seatbelt is unbuckled so I'm sure that was done with a tazer so maybe a tazer will allow me to enable it again? Any help would be appreciated. Thanks.

You have milder weather there than here in Michigan but as soon as the cold weather hit my ESS stopped working. I'm a puss so I always have the seat and steering wheel heat on. It did shock me one mild day when the engine cut at a stop light. I think it is weather related or at least accessory related using the heater as well as the seat and steering wheel heat. It gave the same "not ready" message a few times during the summer when I had the air going full blast. If it doesn't start working again in the spring, I'll have them check it when I take it in for service.

 

[BringTheLightnin]

I really don't want it to end up leaving me stranded because the voltage is too low to start the truck one day

 

[Mr._Bill]

I really don't want it to end up leaving me stranded because the voltage is too low to start the truck one day

If the batteries are getting close to three years old, then I would suggest just replacing both of them. Unless there are other issues with the truck or charging systems, this is the easiest and quickest solution.

Otherwise, disconnect the battery cables so they are isolated, and charge each battery individually. Check the voltage level before and after charging. If letting it sit for a while after charged and the voltage reading is below 12.5 then it needs replaced.

 

[BringTheLightnin]

If the batteries are getting close to three years old, then I would suggest just replacing both of them. Unless there are other issues with the truck or charging systems, this is the easiest and quickest solution.

Otherwise, disconnect the battery cables so they are isolated, and charge each battery individually. Check the voltage level before and after charging. If letting it sit for a while after charged and the voltage reading is below 12.5 then it needs replaced.

How long do they usually last? I was thinking of getting one of those antigravity batteries instead. Although it is under warranty still...

 

[JTR178]

How long do they usually last? I was thinking of getting one of those antigravity batteries instead. Although it is under warranty still...

Free warranty batteries = best batteries.

 

[ShadowsPapa]

Will reset the ESS today when I get home by unplugging the harness and reattaching. Tried everything else

Not sure what you mean by that.
Do you mean IBS? If so, only do that with both batteries fully charged.
Best to remove it from the battery negative post to do that, not just "unplug it".

12.2 volts is way low for the driving you've done.

12.2 VDC at rest, one or both of the batteries is getting tired. Like mentioned, most likely the AUX battery.

Gotta disagree a bit and say - Not necessarily.
That's the lore out there, but multiple members have found it to be the main battery after ASSUMING and replacing the aux battery.
More than one has replaced the aux and gone back and bought a main battery.
I've observed at least 3 forum members state that the main battery was either the culprit, or as bad as the aux.

Sadly the internet has made the aux battery a bad guy.

Since batteries lose capacity over time, especially in the type of use many of these see (occasional use, short drives) I can't see putting a new battery in with one that has diminished capacity.

 

[Ted Striker]

OP, I had the same issue on my 21 Texas Trail with 18,000 miles. Stop/Start Not Ready on the display, but no warning light on the dash. Start/Stop system didn't work.

Took it to dealer service dept. and they replaced the aux battery and it worked for a day or two, then back to not working. Took it back to dealer service dept. and they replaced the main battery and it began to work again and stayed working.

Culprit was main battery bad. Might be your issue too.

 

[ShadowsPapa]

OP, I had the same issue on my 21 Texas Trail with 18,000 miles. Stop/Start Not Ready on the display, but no warning light on the dash. Start/Stop system didn't work.

Took it to dealer service dept. and they replaced the aux battery and it worked for a day or two, then back to not working. Took it back to dealer service dept. and they replaced the main battery and it began to work again and stayed working.

Culprit was main battery bad. Might be your issue too.

Add you to the list of people who found it was the main battery causing issues.........

Sponsored