Auto Start Stop Intermittent Warning Light!

[REDJ33P]

So I'm sure there has been lots of discussions regarding the auto stop feature and the warning lights that appear. I have a new issue that has crept up where I start my Jeep in the morning and my warning light for the auto start stop pops on the dash. When I shut the Jeep off and turn it back on the light remains off. The auto start stop works as normal throughout the rest of the day. However, when I get up the next day start the Jeep for the first time the auto start stop warning light appears and if I turn the Jeep off turn it back on disappears. This cycle seems to repeat daily. It appears that there are something after about a 7 to 8 hour window where the Jeep is turned off that the battery or it appears that there are something after about a 7 to 8 hour window that is causing this issue.
Few years ago I had a similar issue however in that scenario the warning light would come on and stay on. This happened over a couple week period and ultimately that resulted in a replacement of the auxiliary battery. And just to be safe I went ahead and replaced both the main battery and the auxiliary battery at that time. That resolve the issue and never had it again.
So when this issue has crept up I thought the same thing possibly something with the battery. So I went and replaced again both the auxiliary battery and the main battery and after I did that and tested it everything seemed to be going good. Until the next day when I got up started the Jeep after it set for about 8 hours turned it on and again Auto start stop warning light on the dash. Repeat cycle turn off Jeep turn back on light stays off for the rest of the day until about a seven or eight hour. Where it hasn't run.
Has anyone run into a similar issue like this? To me it almost seems like it might be some kind of capacitor that's not holding a charge after it's set for a long enough period of time. Thoughts?

Sponsored

 

[Grace213]

New batteries again.

 

[DaltonGang]

Do yourself a favor, and do the aux battery bypass/delete fix. Before you replace themain battery. Read up on it in several threads, in the Battery section of the Forum. This only takes 5 minutes, and you don't have to buy another aux battery.

 

[Reinen]

Check your high amp fuse array.
It's really easy to blow fuse N3 while changing batteries. I go so far as to slip plastic baggies over the main battery cables and secure them with rubber bands as they're still powered by Aux after they're disconnected. If the cables touch anything grounded N3 will blow. If N3 is blown the Aux battery will not recharge and the message you're getting is one of the symptoms.

The good news is that N4 is unused and has the same amp rating as N3. Just move the cable from the #3 post to #4 as an interim measure until you get a new fuse block.

 

[THAW]

Check your high amp fuse array.
It's really easy to blow fuse N3 while changing batteries. I go so far as to slip plastic baggies over the main battery cables and secure them with rubber bands as they're still powered by Aux after they're disconnected. If the cables touch anything grounded N3 will blow. If N3 is blown the Aux battery will not recharge and the message you're getting is one of the symptoms.

The good news is that N4 is unused and has the same amp rating as N3. Just move the cable from the #3 post to #4 as an interim measure until you get a new fuse block.

If the N3 fuse blows, the system electronics downstream of N3 (i.e. those connected to N1) are powered exclusively by the Aux/ESS battery which is no longer receiving alternator current/charging. The battery will quickly drain and the Jeep will stop running. The OP's Jeep's behavior doesn't indicate a blown N3 PCR/(ESS)* fuse.

 

[Reinen]

If the N3 fuse blows, many system electronics are powered exclusively by the Aux/ESS battery which is no longer connected to the alternator for charging. The battery will quickly drain and the Jeep will stop running. The OP's Jeep behavior doesn't indicate a blown PCR/ESS (N3) fuse.

According to the OP, the message appeared when the Jeep was started 8 hours after Main and Aux were replaced. That could very well be a blown N3 fuse during battery replacement.

It's either that or one of the new batteries is a lemon. A blown N3 fuse is more likely.
Hopefully the OP didn't drive to work today...

 

[Lau3rm]

Did you ever get this figured out ? Was it the n3 fuse

 

[20JUR]

I went through the same procedure you did. I have a TAZER and reset, full reboot and the issue was finally resolved.

Sponsored