Auto Start/Stop ! Light on

[melodyp72]

EDIT: had an appointment with Jeep and it was much worse than I thought. Had a major oil leak that wasn’t detected and it was leaking somehow onto some O2 sensors which was misfiring a lot of stuff. They quoted me $4500 to fix so we ended up trading for a new Jeep end of story.

2018 wrangler JL auto start/stop light with (!) Came on along with check engine light. Checked the batteries and replaced the auxiliary battery.
Drives very sluggish. Scared to drive it…can’t get into Jeep until Thursday. What could be failing???
SW Florida.
Pic for attention.

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[mwilk012]

The auto start stop light is irrelevant, it comes on with any other related system failure, in this case the check engine light. The engine fault needs to be diagnosed. We’d need more information to be of any help at all.

 

[Ratbert]

Not sure what the root cause is, but you need to replace both batteries at the same time. They're wired in a way that problems with one impact the other.

 

[The Last Cowboy]

When one battery goes bad, both are actually bad and they should be replaced at the same time. Ideally you should eliminate the aux battery, then replace the main battery with a group 94R/H7 battery.

The process to eliminate the aux from the circuit is simple, and a common mod among the members here. I got so determined last time that it happened that I completely removed the aux and rerouted the power wires on the PDC.

 

[Terrymo]

Get it scanned for diagnostic trouble codes and report back for better answers. Otherwise people are givung you best guesses. So…tell me about those headlight covers.

 

[melodyp72]

When one battery goes bad, both are actually bad and they should be replaced at the same time. Ideally you should eliminate the aux battery, then replace the main battery with a group 94R/H7 battery.

The process to eliminate the aux from the circuit is simple, and a common mod among the members here. I got so determined last time that it happened that I completely removed the aux and rerouted the power wires on the PDC.

Wow thanks. Hopefully it’s just a battery issue then.

 

[melodyp72]

Get it scanned for diagnostic trouble codes and report back for better answers. Otherwise people are givung you best guesses. So…tell me about those headlight covers.

lol you like? Had to have them.

 

[mwilk012]

Wow thanks. Hopefully it’s just a battery issue then.

It’s not. Retrieve codes and report, any parts store can do this.

 

[Terrymo]

Not my thing but I’m just nosey in general.

@mwilk012 does this for a living. You can trust his advice

 

[melodyp72]

It’s not. Retrieve codes and report, any parts store can do this.

Took it and they said no codes. That’s why I’m going to jeep

 

[hoch]

Well, just pull the fuse and neg cable real quick and see if that’s the issue. Check for loose grounds as well.

 

[Bob Burd]

Well, just pull the fuse and neg cable real quick and see if that’s the issue. Check for loose grounds as well.

Ok, nothing helpful here.

 

[mwilk012]

1. Oil leak from valve cover onto oxygen sensor
2. Blown head gasket.
3. Stuck open EGR valve.
4. Failed ignition coil.
5. Clogged cam phaser / oil control valve.
6. Rodent damaged wiring.

Put em all on a die, and roll it. You’ll get about that close without more info.

If your check engine light is on, there are codes. Whoever tried to read yours was using a low quality scan tool that couldn’t get past the secure gateway. Try an Oreilly or NAPA store if that was an autozone.

 

[melodyp72]

1. Oil leak from valve cover onto oxygen sensor
2. Blown head gasket.
3. Stuck open EGR valve.
4. Failed ignition coil.
5. Clogged cam phaser / oil control valve.
6. Rodent damaged wiring.

Put em all on a die, and roll it. You’ll get about that close without more info.

If your check engine light is on, there are codes. Whoever tried to read yours was using a low quality scan tool that couldn’t get past the secure gateway. Try an Oreilly or NAPA store if that was an autozone.

Thanks

 

[jeepoch]

@melodyp72

Use your cluster's Electronic Vehicle Information Center (EVIC) display. Arrow down, from the left side steering wheel buttons, to the 'Stored Messages' page. Any detected codes from a Malfunction Indicator Light (MIL), which is the Check Engine symbol, will tell you without needing to plug in a diagnostic tool.

If your Check Engine symbol is illuminated, you will have a stored message. If not, that's an Engine Control Module (ECM) software bug. Likely not, I used to write Engine Controller software for Chysler several years back. Diagnostic codes are typically some of the most tested feature sets.

Good luck,
Jay

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