UPDATE: Check Engine light

[wjcook68]

UPDATE: Dropped off 6/17/22 for a CEL and there was a TSB to reflash the computer and during the process, they told me they wiped out the computer. As of 6/21/22 there is still no time frame when a new computer will be available. I have reached out to @JeepCares to see if there is anything they can do to assist. I will keep you all posted. I just want my Gladiator back! We are finally having some nice weather up here.




My 2021 Rubicon, with 4,751 miles, had the check engine light go on. It was idling in park and got really rough and then the CEL came on. I shut it off and restarted and the idle seemed fine but the CEL is still on. This was 2 days ago and the light won't go away. The vehicle runs fine. I now have an appointment for Friday at the dealership. Hopefully it is just a plug or coil pack. It is the 3.6 gas motor. Any one else have something similar happen? I'm hoping it is nothing serious.

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[Rahkmalla]

How's your ESS?

 

[wjcook68]

Hello,

The ESS appears to still be working correctly.

 

[Rahkmalla]

Gotta get the shop to read the codes. Guessing it registered a mis

 

[alpineovernappa]

If you want to know what the code is sooner, most advance auto parts will read the code for you for free or you can buy your own obd2 reader for ~$20 on Amazon. I keep one in every vehicle. Don’t clear the code if it’s going in to the dealer

 

[ShadowsPapa]

People might as well just start tossing out guesses. That light can be anything from engine temp not matching some stat setting, or ignition issue, or O2 sensor issue, or probably 1,000 other things.
Get it checked, like suggested already. It's sort of like asking "why does my arm hurt". Sorry, but a light simply means something was detected by the system that it doesn't like.
For Joe it could be serious, for Sam it could be some simple thing that happened once or twice and is now gone forever.

I see misfires mentioned - The goofy thing is that you can have a light because it detected mistires, or you could have hundreds of misfires and never trigger a light or error code - and if there's a misfire - the cause is also anyone's guess. It would be odd to trigger a light for a single misfire - even dozens of them if they were inconsistent. 1 or 2 won't trigger a thing.
No use even thinking about it until a code reader is connected - read the code.

 

[wjcook68]

Thanks for the replies. You are all correct. I need to get the codes. I think I was just a little peeved that my new truck threw a code. This is the most expensive vehicle I have ever had and I think I just posted out of frustration. That said, I will let everyone know what I find out on Friday.

You all are a great bunch of people here and I am grateful for the knowledge base!

 

[ShadowsPapa]

Thanks for the replies. You are all correct. I need to get the codes. I think I was just a little peeved that my new truck threw a code. This is the most expensive vehicle I have ever had and I think I just posted out of frustration. That said, I will let everyone know what I find out on Friday.

You all are a great bunch of people here and I am grateful for the knowledge base!

We are very interested in finding out just what happened.
Your frustration is absolutely understood! At least you used yours in a controlled way.

I'd say it's the most expensive vehicle I've ever owned, but at the time so was my brand new AMX at $6,000 (I had just graduated college, got my degree, and hadn't yet gotten a job),
and so was my new 84 Eagle wagon at $14,000, and my new 87 Comanche (can't recall the cost of that, perhaps I was purposely trying to forget it LOL), and each vehicle along the way - became the most expensive vehicle I'd ever bought. (some perspective to distract you from the dang light!)

 

[wjcook68]

We are very interested in finding out just what happened.
Your frustration is absolutely understood! At least you used yours in a controlled way.

I'd say it's the most expensive vehicle I've ever owned, but at the time so was my brand new AMX at $6,000 (I had just graduated college, got my degree, and hadn't yet gotten a job),
and so was my new 84 Eagle wagon at $14,000, and my new 87 Comanche (can't recall the cost of that, perhaps I was purposely trying to forget it LOL), and each vehicle along the way - became the most expensive vehicle I'd ever bought. (some perspective to distract you from the dang light!)

Lol. It puts it in perspective and also made me laugh.

 

[Dark_Iron_Mojave]

Hey, similar problem here at 5750 miles - CEL and occasional rough idle and misfires. Jeep has been in the shop for a week. I don't have the codes off-hand, but the ones AutoZone's scanner pulled were basically "system high voltage" "random misfire" "O2 sensor heater high voltage". Dealership's system had a ton more output, naturally.

STAR got involved right away (according to the dealership, STAR called them after my Gladdy was plugged in and the codes hit the system, not sure about all that). They replaced the O2 sensor heater, seemed okay. Did a test drive and CEL came back on. New check this morning and Jeep STAR wants to replace the entire wiring harness for the (and don't quote me, I'm not super mechanical) O2 sensor and catalytic converter system. They're expediting the parts to the dealership for a Monday repair.

 

[ShadowsPapa]

The O2 sensor heater is in the O2 sensor. They don't work cold so there's a heater in them to get them warmed up quickly. So if there was an O2 sensor heater issue, they'd replace the O2 sensor.
However, high voltage indicates the voltage to the heater was too high........ unless they measure voltage drop across the heater to indicate normal operation.

System high voltage - I don't suppose you had the gauges showing when any of this started? Like the gauges in the radio off-road pages, or even in the cluster display in front of you - you can choose what "vehicle information" to see, such as coolant temp, transmission temp, oil pressure, voltage, tire pressure and so on..............

Odd combination of things.........

 

[wjcook68]

Well, I just got the call from the service department regarding my CEL. There was a TSB to flash the PCM and it didn’t take and now the truck is inoperable. Of course the new PCM is on back order and they have no rental cars. I’m not real happy right now.

 

[wjcook68]

UPDATE: Just got a call from the dealer and the backordered PCM should be here 6/30 or before so this is starting to get better at least!

Crossing my fingers all goes well.

 

[Dark_Iron_Mojave]

I didn't have the gauges up, no. Quick update on my scenario, which appears different from OP.

One of the additional sensors ordered showed up damaged so they ordered another and it should be in tomorrow. They think something was off in the wiring harness that caused the voltage to read incorrectly. We'll see if everything resolves once they do the work.

To OP's frustration, it seems most all dealerships are out of loaners these days due to low inventory, so I definitely feel you on being mad about that.

 

[wjcook68]

I hope your situation gets resolved quickly Dark_Iron_Mojave.

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