Engine Check Malfunction Indicator warning light Triggered on Mojave

[joeym7]

It’s been on for 40 miles? Run to any auto parts store. They should be able to pull the code(s).

You’ve got the exact opposite issue that I did. My issue was that the light would never stay on long enough to do anything with it…and the code didn’t store for me to be able to pull it.

...Mine started at the beach which is about 10 miles away, so I need to give it up to 30 mi more...

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[ZoMojave]

I am not certain if your JT is included in this but probably a dealer visit is needed. I have a '22 Mojave (built in Feb. '22) and my check engine light came on upon each start up for 4 days (in May if I remember correctly). Ended up needing the Z37 service bulletin PCM reflash. Some dealers call it a recall. After waiting a week to get it after making the appt. the light went off on its own. I still brought it in, and my dealer performed the PCM reprogram. I haven't had an issue since.

I also received a notice in the mail after I had this procedure completed. Here is a link from another thread:

Recall Notification (jeepgladiatorforum.com)

 

[joeym7]

I am not certain if your JT is included in this but probably a dealer visit is needed. I have a '22 Mojave (built in Feb. '22) and my check engine light came on upon each start up for 4 days (in May if I remember correctly). Ended up needing the Z37 service bulletin PCM reflash. Some dealers call it a recall. After waiting a week to get it after making the appt. the light went off on its own. I still brought it in, and my dealer performed the PCM reprogram. I haven't had an issue since.

I also received a notice in the mail after I had this procedure completed. Here is a link from another thread:

Recall Notification (jeepgladiatorforum.com)

Thanks for your post...I actually had the Z37 update in August...I didn't have any check engine events until yesterday.

I'm wondering if yours might have been just a random event which cleared on its own that may not have had anything to do withZ37. But no way of telling of course.

 

[ZoMojave]

Thanks for your post...I actually had the Z37 update in August...I didn't have any check engine events until yesterday.

I'm wondering if yours might have been just a random event which cleared on its own that may not have had anything to do withZ37. But no way of telling of course.

Certainly, a possibility. My JT was in the VIN range to have the update done anyway. I wouldn't mess with the auto parts store code read. You'll wind up at your dealer anyway. Keep us posted on what you find. Retired techs like myself are always curious.

 

[joeym7]

Certainly, a possibility. My JT was in the VIN range to have the update done anyway. I wouldn't mess with the auto parts store code read. You'll wind up at your dealer anyway. Keep us posted on what you find. Retired techs like myself are always curious.

I have an appointment for next Tuesday at the dealer. I am going to take her on the highway today and put 20 or so miles on it and hope it clears.

 

[PsyRN]

My issue was that the light would never stay on long enough to do anything with it…and the code didn’t store for me to be able to pull it.

This happened to me recently for the 2nd time in 2 years. CEL started flashing, but before I could pull into a safe spot, it stopped. It also didn't store, so it looks like nothing happened. I'm going to think it was a single misfire. Kind of like a single, out of sync heartbeat, that corrects itself and we all keep moving on. Both times I was accelerating up an incline and the revs popped up quickly.

 

[joeym7]

This happened to me recently for the 2nd time in 2 years. CEL started flashing, but before I could pull into a safe spot, it stopped. It also didn't store, so it looks like nothing happened. I'm going to think it was a single misfire. Kind of like a single, out of sync heartbeat, that corrects itself and we all keep moving on. Both times I was accelerating up an incline and the revs popped up quickly.

It might have a minor case of "AFIB" as an analogy .

It is "funny", I had a check engine in my STS going (it is 20 years old so I get them about 2 times a year - they always clear after a while), I took the car for an errand this morning...When I got back in it to go home it was gone...I hope this 2022 Mojave displays a similar ability to "self heal". I really don't expect an almost brand new vehicle to be doing this kinda of crap, and if it keeps happening I am not going to be happy about it - especially if trips to the dealer are required. I would put that in the marginal quality bucket as I never had a new car which did this kind of thing, so we will see.

Anyway, I am going for a 2-for-Sale , hope the MO clears today.

 

[ShadowsPapa]

You'd be surprised at how many "near new vehicles" do this sort of thing - mine at 56 miles. 3 times since that first.

I'm a bit baffled as to the resistance to finding out the source, the reason....... any time I see a MIL, I want to know WHY. If it's catastrophic, I'd want to know, if it's minor like my very specific misfires, i'd want to know that.
It could be anything from "she's gonna blow, cap'n" to "we have a misfire issue not harmful but indicative of a larger issue that won't get better".
Things don't self-heal unless you are one in a million extremely lucky. Once the conditions match the original incident, it's more likely than not to happen again.
So why not find out why instead of sitting back hoping?

You don't expect it to be doing it - but it is, so why not get the code read and find out?
It's made by humans - heck, the owner of a $70,000 Mercedes doesn't "expect" things to fall apart on the road, but it happens. The owners of Cadillac SUV don't expect steering to lock on a new vehicle, but it happens.

I guess I am just more curious and needing to know root causes than most. Any time I see a MIL come on, out comes the diagnostic tools. Even if it's just to know the cause.

Mine only triggers under a very specific set of conditions and yet I know that even though it likely won't happen for weeks and hundreds or thousands of miles - there's something at the root of the issue and it's likely to be causing other problems.
In my case, it's very obscure and no dealer will be able to make it happen on their watch - but it appears there may be an awareness inside Jeep engineering and the more information, the more details I gather, the more likely a fix in short order and they won't have it for weeks.

 

[joeym7]

I think I mentioned above, given it is not blinking, giving the manual says "The vehicle should be serviced (IF) the light stays on over several different driving styles", and given I do have an appointment next Tuesday, it makes all the sense to me that it is a fair risk reward approach to put a few miles on it before taking it in...Remember, it is my pleasure craft, I don't use it for day to day errands, I use it "at will".

The lady at the dealer told me I couldn't get it in sooner anyway UNLESSS the light was blinking.

No need to panic at this point.

 

[ShadowsPapa]

I think I mentioned above, given it is not blinking, giving the manual says "The vehicle should be serviced (IF) the light stays on over several different driving styles", and given I do have an appointment next Tuesday, it makes all the sense to me that it is a fair risk reward approach to put a few miles on it before taking it in...Remember, it is my pleasure craft, I don't use it for day to day errands, I use it "at will".

The lady at the dealer told me I couldn't get it in sooner anyway UNLESSS the light was blinking.

No need to panic at this point.

I missed that part.

True, very, no need for "panic" - it's just that what I saw as an apparent lack of curiosity or wondering, or "what's up with this" seemed odd.

It will be VERY VERY interesting to see if they find a P0300 stored in there.

In any case, good luck.

I also use mine "at will" as there's our GC and my SX4 and if I ever get the dozen other restorations done for people, I might eventually get my other car together although I can't take it out in rain and it's downright dangerous on snow.
I thought it was going to be an occasional use vehicle, maybe 6,00-6,500 miles a year TOPS, if even that and I've already hit just shy of 6,000 miles 3 1/2 months in.
So much for a low miles discount on insurance.

 

[joeym7]

Well per the manual, I have driven it past the 40 mile point, and it is still on. Started up a few times on this little trip also...Really put here to work on the highway too - she is running so nice, I'm guessing the dealer next Tuesday will not find anything significant (I hope anyway )...I may drive her around town over the weekend, but nothing else planed before Tuesday.

Fun truck, I had a good time putting her through her paces...

Not even qualified as a "first world problem" to go to the dealer, just a PITA.

On another note, they probably put an extra cylinder or two in my Mojave ;-) because I just can't figure out why people complain about its acceleration being lacking (per that other thread that has been around a while).

 

[ShadowsPapa]

Not even qualified as a "first world problem" to go to the dealer, just a PITA.

Until a cam goes south
That's where I'd be - since it's a total unknown, no one knows if it's serious and causing further damage, or a simple bad coil pack or spark plug issue (a known thing in the 2021 Jeep 3.6)
Since it didn't reset the light on its own (mine took 3 start cycles, then reset, it wasn't miles) likely the issue still exists.
There are different "classes" of issues - some if they don't exist in enough consecutive starts, the light will reset and not come back until it happens again.
Others are more serious and the light stays lit until reset, while others may be present at each subsequent start, so the light never goes out. If the issue is present at each start, then the light stays on. Miles won't matter.
It could be as simple as the heater circuit of an O2 sensor. No big deal - once the engine is warm, all is fine (but the light will stay on)

Odd thing about misfires -
My wife's Jeep was bucking like a wild horse - I was afraid I wasn't going to make it back home with it and yet the light NEVER set, the testing showed the light was never requested! Miles of bucking and missing you could feel - it was pretty bad.
Mine set the light and yet I couldn't even feel it misfire the first time. The engine was smooth, no vibration, no uneven feeling, it was just off idle moving slowly out of a parking lot. And it set the light. The next time it was bucking wildly - the light flashed on and off - but didn't stay on. In fact the light went out while it was still missing, then it settled down.
So - first time - smooth as silk, it set the light
Second time - rougher than a crazed bull ride and it didn't set the light.
Third time - set the light but it went out later. You could feel it missing. And this final time I could tell it wasn't smooth, but it never set the light.
I guess the PCM can't make up its mind.

 

[joeym7]

I missed that part.

True, very, no need for "panic" - it's just that what I saw as an apparent lack of curiosity or wondering, or "what's up with this" seemed odd.

It will be VERY VERY interesting to see if they find a P0300 stored in there.

In any case, good luck.

I also use mine "at will" as there's our GC and my SX4 and if I ever get the dozen other restorations done for people, I might eventually get my other car together although I can't take it out in rain and it's downright dangerous on snow.
I thought it was going to be an occasional use vehicle, maybe 6,00-6,500 miles a year TOPS, if even that and I've already hit just shy of 6,000 miles 3 1/2 months in.
So much for a low miles discount on insurance.

What Pray-Tell is the P0300 code indicative of?

Interesting that a person like you who is into all the ins and outs mechanically of this Truck can't figure out why yours keeps going off, even with the "help" of the dealer...Not good IMO, Jeep needs to do a better job with this....Yea a "relatively" benign warning light isn't the end of the world, and one can be very grateful if that is the most severe problem they have with this truck, but it still tells me, if it can't be fixed after a visit or two, and becomes a new Gladiator "feature" lol, some Jeep designer(s) doesn't know what he is doing. Unacceptable on a new car at this ridiculous price point plain and simple.

I don't generally sell my cars until they totally fall apart , but I wonder how much this "new-feature" - we can call it the "Annoying Engine Warning Light" package (and it comes standard equipment -lol) is going to take off resale value for those who do flip occasionally.

 

[ShadowsPapa]

What Pray-Tell is the P0300 code indicative of?

Interesting that a person like you who is into all the ins and outs mechanically of this Truck can't figure out why yours keeps going off, even with the "help" of the dealer...Not good IMO, Jeep needs to do a better job with this....Yea a "relatively" benign warning light isn't the end of the world, and one can be very grateful if that is the most severe problem they have with this truck, but it still tells me, if it can't be fixed after a visit or two, and becomes a new Gladiator "feature" lol, some Jeep designer(s) doesn't know what he is doing. Unacceptable on a new car at this ridiculous price point plain and simple.

I don't generally sell my cars until they totally fall apart , but I wonder how much this "new-feature" - we can call it the "Annoying Engine Warning Light" package (and it comes standard equipment -lol) is going to take off resale value for those who do flip occasionally.

It's a multiple cylinder misfire code. P0301 would be misfire on cylinder #1, P0302 would be misfire on cylinder #2 and so on.
Mine is P0300 meaning it's happening on more than one cylinder.
It happens on #2, #4 and #6 in that order of worst to not as bad as the first.
#2 is the worst, a lot of misfires, #4 is next with too many but not as bad as #2 and then #6 is bad, but not as bad as #4.
A misfire can be caused by quite a few things - an O2 sensor, for example, or anything else that's unique to that left side engine bank. It doesn't happen on bank 1 on the right side. Those are pretty normal with low misfire counts in the 0 to single digit area. So I'm trying to narrow it down even further with freeze frame captures and other data. Saves time.

It's not been to a dealer to even be looked at.
No use until I have more information. And since it is only under very specific conditions and always comes out of it by itself after a minute or two - I'm gathering data.

If I were diagnosing a charging system issue on a classic car, I'd want several points of data - voltage at battery, voltage at alternator output post, voltage at diode trio or field diode post, any vehicle ALT dash light indicator - on, off, on but dim, and any other information I can get. That way I'd have the issue narrowed down either to the exact or specific cause, or at least to only 2 or 3 possibilities.
Same for any other issue. Gather data, troubleshoot instead of doing what the internet, forums and fakebook all do when people come in and say "my car is doing xyz, what's wrong" - toss stuff at the wall and see what sticks.
With charging systems it's always "put on a new regulator" or "change the alternator" or "you have a loose belt" and usually every answer is wrong, the guy has spent a couple hundred dollars and days swapping parts - and it was a connection - a free fix.

 

[joeym7]

It's a multiple cylinder misfire code. P0301 would be misfire on cylinder #1, P0302 would be misfire on cylinder #2 and so on.
Mine is P0300 meaning it's happening on more than one cylinder.

Do you here anything "audible" with these misfire events?

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