Service 4wd Light

[dgerb]

After doing Top of the World trail in Moab today the service 4wd light came on...what does mean? The offroad app also has error message..

 

[Jeepstin392]

Check fuses and connections such as front and rear axle, wheel speed sensors, transfer case, etc. seems a lot of people have experienced loose connections.

it’s under warranty, hit up the dealer. Jeep is also aware of the high number of these incidents.

 

[scarab]

Happened to me once as well, I reseated loose fuses and so far so good, haven’t seen service light since - knocking on wood.

 

[Jeepstin392]

I will say, the 1st I got home won’t mine, I checked the fuses. I would say easily more than half were barely seated.

 

[dgerb]

I'll have to check fuses and remove the tazer and see what happens...

 

[OllieinAZ]

I am glad you guys posted this, I had no idea and thought I blew up a diff after some "spirited" off-road driving...
Sure enough, after reading this tread and re-seating my fuses, all is good.
Thank You, Guys!!!

 

[YukonCornelius]

Had this happen at about 300 miles. Reseated every fuse (none of which were fully seated until “click”) and it went away and hasn’t come back now at 2100 miles. Took it in anyways the following week and diagnostics didn’t find anything. Hopefully, it’s just the “Fuse Plague” for you as well….

(assuming it’s the SRVC 4WD indicator just above the fuel gauge. )

 

[Bocephus]

Happened to me (service 4x4) at dealer now. Apparently threw a u1440 code, among others. They’re not sure what’s up yet, but “replacement of transfer case” was mentioned. Pretty sure that’s not happening. It came on only in 4low and didn’t return the next day when I put in 4low for several miles. Also having trouble getting the sway bar to connect / disconnect, which dealership says may be related, which doesn’t seem to make sense.

 

[HEAT392]

Happened to me (service 4x4) at dealer now. Apparently threw a u1440 code, among others. They’re not sure what’s up yet, but “replacement of transfer case” was mentioned. Pretty sure that’s not happening. It came on only in 4low and didn’t return the next day when I put in 4low for several miles. Also having trouble getting the sway bar to connect / disconnect, which dealership says may be related, which doesn’t seem to make sense.

I’ve popped this same code. Had a Stellantis ticket but my original dealership never closed the loop with their engineering team. The folks at Stellantis were helpful but since this code clears itself it (heat related? Clutch pack?) was hard to recreate/get it over to them while it was still on.
If you take it in I would call Stellantis and have them document the ticket and issue history especially if no solid resolution.
And finally for better or worse, I have used the Tazer once to clear this code via clear DTC. Because, I find while this code is flagged there is ??? Issue in low gear effecting handling. Almost like the axles are locked.

 

[Bocephus]

I’ve popped this same code. Had a Stellantis ticket but my original dealership never closed the loop with their engineering team. The folks at Stellantis were helpful but since this code clears itself it (heat related? Clutch pack?) was hard to recreate/get it over to them while it was still on.
If you take it in I would call Stellantis and have them document the ticket and issue history especially if no solid resolution.
And finally for better or worse depending on circumstances I have used the Tazer once to clear this code via clear DTC.
I find while this code is flagged there is ??? Issue in low gear effecting handling. Almost like the axels are locked.

My jeep is at dealership now and still getting looked at. They referenced another 392 in their shop with similar dash alert, but different codes. Reference made to a service bulletin. Honestly my service advisor is not an expert, but she couldn’t be more helpful or earnest. Calling tech experts outside the dealership, and spent 40 mins chatting.

Heat being a possible factor makes sense, I drive about an hour at 80mph to get to the trail head, temps in the 90s. 2 days later, I was throwing no alerts in 4 low. I wondered if it was related to my gearing calibration - my shop failed to set my tazer to 4.88, and I remained at 3.73 until recently. I wondered if correcting the gear setting (which I did via tazer) resolved the issue. I didn’t experience any apparent problems while on trail in 4 - low, even though dash alert lit. (Aside from sway bar disconnect fails - couldn’t get it to unlock. )

Fwiw my dealership told me they had no capability to hard code my new 4.88 gearing aside from new PCM. And was going to be $295 to hard code my 38s. Pass. I will just stick with tazer and unmarrying / marrying for dealer visits.

 

[HEAT392]

My jeep is at dealership now and still getting looked at. …

Fwiw my dealership told me they had no capability to hard code my new 4.88 gearing aside from new PCM. And was going to be $295 to hard code my 38s. Pass. I will just stick with tazer and unmarrying / marrying for dealer visits.

A trail dash will take off the Governor, and you’ll need a new PCM to boot!

I am glad you have a good team there helping. Good luck on this service visit I hope they can get your Jeep back to you 110% & quickly, too!

Some other anecdotes here, related:
15.6k miles 2021

Saw this early on… I’ve seen it rarely, but tracked it pretty close and detailed the whole thing to Stellantis via tickets. Enough that if it’s an issue before I drive out the warranty, I’ll have first flagged this SRV4WD light before 2k miles. I have the hard copies with miles and dates but I’m not going to pull them for this post. And, I haven’t gotten it to stay on long enough for a dealer to catch the code live but the history is in the ?CM and I have video of the SRV4WD light and the low gear issues. More on the low gear issues in a second.

Again, seen it rarely. Mostly when I’m running 1,200+ miles in a under or at 24rs running near continuous at highway speeds. Also, I see it when I turn the Jeep back on from either quick restaurants, rest steps or gas stations during this type of run. It’ll come on when I turn the motor over, then, if I drive on it, it’ll clear itself. I have also let it sit, off, to clear. The first time I saw this light, though, was only about 45 minutes of 65mph and came on as I parked. The drive was calm, nothing crazy, no stomping it or holding RPMs… Other than that, it’s been as above mentioned.

Low gear issues. To be clear I mean the 4WD Auto the Jeep 392 has. In the owners manual, in different chapters, it contradicts itself on the topic (of 4WD Auto). When this SRV4WD light is on, cornering in first or reverse behaves as if the axles are locked. UConnect and gauges indicate they are not, but the feeling driving is if they were locked. Once out of first, the vehicle behaves normally.

OK- hope some of this info helps someone. This was an issue that had bothered me especially at first. Enough that even posting about it would’ve made me annoyed. Really though I have made a choice not to carry stress about it, until a real issue arises. Will be keeping an eye out for your update. Thanks for posting.


TLDR; if you haven’t seen this issue just keep scrolling.

 

[Rscx4]

I had this happen to me. When the light came on it seemed like the front axle was locked as in fully engaged. Hard to notice except when pulling in to a tight parking spot to a u-turn, you could tell the locker was seemingly on. The fault was a "transfer motor." Apparently there is an electric motor that assists the transfer in doing it's business. The dealer replaced it (long wait) and it has been fine ever since.

 

[Rjezonie]

Check fuses and connections such as front and rear axle, wheel speed sensors, transfer case, etc. seems a lot of people have experienced loose connections.

it’s under warranty, hit up the dealer. Jeep is also aware of the high number of these incidents.

Just happened to me today after putting my 392 into low. Sway bar light warning came on and Serv 4wd. Also wouldn’t shift out of 1st.

 

[Damnright]

Reading this thread is so depressing. Mine is heading in tomorrow morning for a diagnostic eval. The quality is just not there.

 

[Rjezonie]

Did you check the fuses to make sure they were seated correctly? I checked mine and a few weren’t totally tight. However, problem still occurred…only in 4low. 4 high is totally fine though. Also removed my tazer to see if that was an issue as someone suggested. Didn’t change a thing. Maybe I’ll unmarry the tazer and try again tomorrow. Most likely though I’ll have to make a service appt:/

 

[thexr6]

Did you check the fuses to make sure they were seated correctly? I checked mine and a few weren’t totally tight. However, problem still occurred…only in 4low. 4 high is totally fine though. Also removed my tazer to see if that was an issue as someone suggested. Didn’t change a thing. Maybe I’ll unmarry the tazer and try again tomorrow. Most likely though I’ll have to make a service appt:/

Had same issue, posted about it, been at dealership for 6 weeks awaiting a new transfer case.
So - either check/ fill transfer case fluid or have dealer do it. Would not recommend driving it - my TC was a filled with shredded, oily metal, till it is diagnosed/repaired

 

[Rjezonie]

Had same issue, posted about it, been at dealership for 6 weeks awaiting a new transfer case.
So - either check/ fill transfer case fluid or have dealer do it. Would not recommend driving it - my TC was a filled with shredded, oily metal, till it is diagnosed/repaired

Geez thanks for the heads up! Will definitely check the fluid tomorrow morning. Hope you get this all straightened out soon. I’m sure I’ll be taking it in regardless now since nothing else seemed to fix it.

 

[Kevin71]

I had this happen yesterday after some aggressive driving. It acted like an old 4x4 that wouldn't go back to two wheel drive. Like others said, especially in first or reverse. I switched to manual and pulled out the driveway in second gear; did the same at a couple of stops. Shut her off. Started back up after several minutes and it’s all better, light is gone and isn’t locked up anymore.

 

[thexr6]

I had this happen yesterday after some aggressive driving. It acted like an old 4x4 that wouldn't go back to two wheel drive. Like others said, especially in first or reverse. I switched to manual and pulled out the driveway in second gear; did the same at a couple of stops. Shut her off. Started back up after several minutes and it’s all better, light is gone and isn’t locked up anymore.

I would have it checked out. Similar symptoms. “Felt“ like it was in 4 wheel drive , intermittently light on and off, and then transfer case failure.

 

[dog]

I would have it checked out. Similar symptoms. “Felt“ like it was in 4 wheel drive , intermittently light on and off, and then transfer case failure.

I just replied to your other thread where you were talking about the SERV 4WD light - now I'm terrified, sounds like we have exact same symptom - wheels feel like they're binding on tight turns...

I just noticed this today, and definitely haven't ever had this happen before... so I'm hoping it's not trashed. Obviously still under warranty, but *really* hoping to avoid new transfer case!