ESS failure... at 50 MPH?

[whoisvince]

I haven’t seen this issue posted yet...

Bought a JLU Sahara last month, automatic trans with Selec-Trac, and 3 weeks ago I noticed an occasional engine stutter or sudden hesitation at random while in motion. The Jeep stalled while pulling out of my garage last week. Two days ago I was driving at 50 mph when I felt 3 successive lurches which felt like the engine was going to stall, then got a "Service Stop/Start System" warning on the dash without a CEL.

I took it to the dealer, who couldn’t find an error code. They wouldn’t be able to work on the car until Monday, so I drove it home to bring it back on Monday.

Today, it near-stalled three times again doing 30 mph and threw a CEL. I have no problems if I disable ESS. Why would ESS have anything to do with driving at speed? Has anyone else experienced this? I always drive belted in, and didn’t open the door. The hood is latched tight.

Here’s a dash light photo

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[BillyHW]

I got this to read trouble codes for my car:

https://www.amazon.com/BlueDriver-B...45012&sr=1-4&keywords=bluedriver+obd2+scanner

 

[am1978]

Did you check to make sure all fuses are seated correctly?

 

[Jeepsk8]

Sounds like the fuse bar is bad. It has a fuse for the secondary ESS battery.

 

[am1978]

Seems like fuse seating or fuse box issues are usually the culprit for the majority of issues on JL.

 

[wranglerguyman]

I had the same issue. I checked the fuse box as excessive heat was coming from there and it turns out majority of the fuses were NOT seated properly.

 

[whoisvince]

Wow, you guys weren't kidding about the fuses. The majority were loose. I'll drive it for a bit and post my results.

 

[AwCrimety]

Had similar issues, mine only occured under heavy acceleration and high RPMs. Go out and give it the beans and see if it occurs again. My rough idle never stalled, but always got CEL under heavy throttle

 

[whoisvince]

Well, I reseated the fuses, and drove around for about 20 mins yesterday without issue. The CEL also cleared. I hope that's it, but I'm still taking it to the dealer tomorrow. Very unsettling.

 

[BillyHW]

So why can't FCA seat fuses correctly?

 

[PavementWarrior]

So why can't FCA seat fuses correctly?

They wiggle loose while they are welding the frame with peanutbutter

 

[whoisvince]

I bought an OBDII scanner which gave me code PO339: "Crankshaft Position Sensor A Circuit Intermittent". Sounds just like this post: https://www.jlwranglerforums.com/forum/threads/autostart-ess-failure.8908/

I'm still taking it to the dealer tomorrow. I'll keep you guys posted.

 

[am1978]

So why can't FCA seat fuses correctly?

Machines

 

[old8tora]

So why can't FCA seat fuses correctly?

fca stupid dumb idiots also explains having the ESS in the first place .

 

[XTrooper]

fca stupid dumb idiots also explains having the ESS in the first place .

Vehicle manufacturers aren't adding ESS because they necessarily like it or think it's a good idea. They are being pressured into adding crap like this because they have to meet new, stricter fuel economy standards by 2025.

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