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"Service 4wd system" indicator light

CanAmMick

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We’ll this is the second time it’s happened to me. About 8 months ago it happened when I was trying to go into 4 high to drive up a steep hill. Service 4 wheel drive came on and the transmission would not shift out of 1st gear. Luckily I was only about a mile from the house. Only thing I did after driving home in first gear was shut the Jeep off. When I started it again the light was out. Jeep ran fine after that.

4 days ago it happened when I was trying to go into 4 low to drive through a real slick icy area. I tried shutting it off but that didn’t do it. Was about 40 miles from home. I called a friend, and we loaded it onto a trailer and got it back home. It was about 2 hours later when we decided to unload it. I cranked it up and no light! Jeep ran fine.

This thing is out of warranty, so with all the problems I’ve had with it over the 3 1/2 years I traded it in on something more dependable. Last time it was in the shop they kept it 2 months exactly. Glad it was under warranty at that time.

a GMC 1500 Denali 4x4. I’m going to really miss my Jeep, but not all the problems that I had with it. I don’t believe there is anything like it for off road. Guess now I’ll have to take my Polaris Ranger when I want to go have a little fun.

I do have some things that I want to give away if I can find someone that lives in Wyoming , Sheridan, Buffalo, Gillette, or Casper area. I don’t want to ship it, so if you guys know someone that lives in Wyoming let them know that I have some things that they may want/need. Wayoflife CB bar (just mounted my HAM radio 2 weeks ago) wheel spacers that I used for about 2 months, and 4 fram oil filters (for 3.6L). I believe that’s it.


If I can’t find someone around here to take the stuff off my hands I’ll think about shipping it if someone pays for the shipping.

One last thing, I can say that this forum has been a great asset for helping with my Jeep. Everyone here has always been great to deal with. Most of you guys go out of your way to help others. The knowledge base here is just unbelievable. I sure hope I can find another forum that has people like you guys and gals. Thanks for everything.
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AZBRIT

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In the image I am in 4-lo. The service 4wd and the left indicator doesn't show that I am in 4-lo. I will check my fuses for sure, but if anyone is having this issue I would like to understand when it happens and if you have a fix,

4wd issue_LI.jpg
In the image I am in 4-lo. The service 4wd and the left indicator doesn't show that I am in 4-lo. I will check my fuses for sure, but if anyone is having this issue I would like to understand when it happens and if you have a fix,

Jeep Wrangler JL "Service 4wd system" indicator light 4wd issue_LI
Hi - did you ever get a fix for this issue? I too have the Serv 4wd light come on (also with the ABS and ECS lights). It seems to happen sporadically, typically while wheeling and not on road. Most of the time I can just switch off the ignition and restart, warning lights go out. Taken back to dealer once who tightened battery terminals and uploaded an ABS module update - took out off road and same issue, starts with ECS warning then ABS and then Serv4wd.

IMG_6744.jpeg
 

Wmbrooks

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I am here to add the same information. I have a new 2021 JLU Rubicon, with the 4wd Serv light on. Its already at the dealership with only 7,000 miles. I haven't even used the 4WD yet or got it on a trail (just bought it) with my trail group ATLOFFROAD. Hopefully they will have it back to by the end of the week. I'm pretty sure it's a sensor or connector when the dealer scanned it had a code that mentioned "Axle Disconnect". I checked the fuses, and they were fine. I am assuming it's the connector attached to the sway bar disconnect on the passenger side axle. I have always had a JK, so I'm not sure about how the JL is set up. This is my first Rubi however also. After I saw the light, I tried to test the 4WD and this error light will prevent any 4WD use.

My concern is this, even if it is a senor or connector issue. Why is the software preventing the owner from using 4WD, what if I'm in the middle of a trail and lose 4WD because of something small like the connector? That is a safety issue, when the owner needs 4WD, they need it, it's not an optional feature it's a mandatory requirement that's why we pay what we pay for these Jeeps. In that scenario I would have to get towed back to the beginning of the trail. Or turn it off and manually slap it into 4-LO and then turn the vehicle back on and see if that bypasses the error. It seems like the software in the computer is preventing any 4WD use. That needs to be recoded from the computer and removed entirely with the exception of Transfer Case errors. Thats actually a safety issue.
 

CanAmMick

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Would yours shift in to any other gear? Every time it happened to mine it wouldn’t shift out of 1st gear. I didn’t like getting rid of my JL, but it just had too many dang problems! I really miss it, but not all the problems I had with it. It was one of the first built JL’s.
 

rubiria

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Well… after popping my “Off Road” Cherry this morning in my ‘22 JLUR, I get the dreaded ABS Light and “Serv 4WD” indicator on the Cluster 40 miles afterwards.

Jeep Wrangler JL "Service 4wd system" indicator light 417539B4-6C81-4B3D-9A8A-C1DCD820BBE8

Jeep Wrangler JL "Service 4wd system" indicator light C8558A7D-E14C-4F0E-9303-425FA7C50274


My assumption would be a loose ABS Speed Sensor Wire, as stated by many. But I guess it’s a Trip to the Dealer very soon… 😪
 

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Zandcwhite

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So... I had same issue with “serv 4wd” light that came on just on my way home. First time since purchasing my jeep last summer that I drove with 4wd since we just got hit with a bunch of snow in Illinois. I checked the fuses like previous posters suggested in other threads... and I found at least 15!!!!(unbelievable!) were loose. All of the giant ones for “hi” (assuming my for the 4wd but I don’t know for sure) were all incredibly loose. I pushed every one of them in that I found loose and properly seated them. I started my truck again and the light is off after shifting to 4wd. I’m hoping this was my fix, but almost too easy to be true. Especially when I bought my truck brand new— a 2020 rubicon jlu.... how can that many fuses be that loose at same time unless it is due to some lazy turd at the factory not giving a crap when putting it together??!! To me, that is incredibly unacceptable and would be nice if jeep would improve their quality inspections... or discipline when they find an employee isn’t doing the checks they should be.. or the work they should be!! A $60k truck should have all the fuses seated properly from factory. In any event, for those who have read this long- thank u! And try your fuses first!
I don't think any person actually puts their hands on the fuses. Odds are they are assembled in an automated system and the machine that seats them is calibrated on the low side to avoid breakage. I believe fca buys the fuse panel assembled from a third party vendor. Should they have someone go through and check things like this during final assembly? Absolutely. Clearly it's not a big enough warranty issue for them to feel the need to fix it though as they are 4 years in to the same process.
 

mwilk012

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Well… after popping my “Off Road” Cherry this morning in my ‘22 JLUR, I get the dreaded ABS Light and “Serv 4WD” indicator on the Cluster 40 miles afterwards.

Jeep Wrangler JL "Service 4wd system" indicator light C8558A7D-E14C-4F0E-9303-425FA7C50274

Jeep Wrangler JL "Service 4wd system" indicator light C8558A7D-E14C-4F0E-9303-425FA7C50274


My assumption would be a loose ABS Speed Sensor Wire, as stated by many. But I guess it’s a Trip to the Dealer very soon… 😪
Can we place bets on what’s wrong? I’ll guess front wheel speed sensor reading implausible.
 

rubiria

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Can we place bets on what’s wrong? I’ll guess front wheel speed sensor reading implausible.
Yup, that's exactly what it was. The ABS came on upon arriving to the Ballet Studio for Class. Once I left for Class, everything all went away. Two days, and nothing has come back again (knock on wood).

Yes, it dawned on me at how extremely sensitive these ABS Sensors are. Ironic for something that's designed for off road capabilities.
 

mwilk012

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Yup, that's exactly what it was. The ABS came on upon arriving to the Ballet Studio for Class. Once I left for Class, everything all went away. Two days, and nothing has come back again (knock on wood).

Yes, it dawned on me at how extremely sensitive these ABS Sensors are. Ironic for something that's designed for off road capabilities.
What’s even worse is that it can cause the FAD to disengage, thereby losing 4WD.
 

Rufus

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2 door Sport, 3.6, 6 spd, LSD…just got the Serv 4WD light this morning on a coffee run. Didn’t come on again the next couple of trips. I have previously checked the fuses. I haven’t used 4WD since the last snow (maybe 2 months).

I’m going to put this in the bucket with the Engine Start/Stop Disabled and ESC Not Available warnings which disappear and about which the dealer had no clue.
 

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mwilk012

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2 door Sport, 3.6, 6 spd, LSD…just got the Serv 4WD light this morning on a coffee run. Didn’t come on again the next couple of trips. I have previously checked the fuses. I haven’t used 4WD since the last snow (maybe 2 months).

I’m going to put this in the bucket with the Engine Start/Stop Disabled and ESC Not Available warnings which disappear and about which the dealer had no clue.
They didn’t try very hard then.
 

Dyolfknip74

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If “serv 4WD” is lit, you are not in four wheel drive.
Nope. Not always. I've been battling tcase motor and motor sensor issues. Everytime I wheel. I get scv4wd. Whether or not I have 4wd when it's lit changes but I have definitely kept 4wd with it a lot.
Today it was acting differently and only really coming on when I was giving it gas.

So far they replaced the tcase motor and inspected harness. The active code is tcase motor position sensor but apparently that's part of the motor which was just replaced so they're going to be stumped again. FML.

Sorry for the necropost was looking for similiar issues.
 

Dyolfknip74

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Needs a transfer case.
And they FINALLY recognized that this mornng. New one on order.
How did you know that though? They literally did everything except replace the tcase. Checked wiring. Replaced tcase motor. This past wheeling trip though, the light would only come on when I was hitting the gas or putting torque on the tcase. I think that's what finally got them to order it.
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