Sponsored

“Service Axle Locker System” Light On

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
Add me to the "gear oil in the sensor" list. :mad:
I have an open case with Jeep Cares, but of course that isn't going anywhere.

I've dug into the issue quite a bit and it seems like the fine metal particles in the gear oil are shorting the sensor's PCB. You can confirm this yourself by checking the resistance between the two outer pins on the sensor. If there is any continuity (any resistance shown, rather than an open circuit) then the sensor has been contaminated with oil. I can't remember which two pins that corresponds to on the 4-pin axle connector, but you could check it there without taking off the diff cover if you knew which two pins to check.

https://www.jlwranglerforums.com/fo...arranty-part-not-available-for-puchase.54531/
Ahhh the missing piece... metal silt. I thought it was the gear oil itslef but you're right, it's super fine metal silt suspended in the oil causing the short.
Personally I'd look into the Z Automotive harness for $175 and screw the dealer.
Sponsored

 

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
That's frustrating! Thanks for the info. HEY, can you please let me know WHERE I should disconnect the harness while waiting? Is there just one running into the rear diff? Pardon my ignorance around this; I haven't messed around underneath. Thanks!
Replied to your PM.
 

ibmiked

Member
Joined
Apr 29, 2020
Threads
0
Messages
9
Reaction score
18
Location
ATX
Vehicle(s)
JLRU
Update for my locker situation. On 17 July, my dealer called and said FCA told them to order a new rear axle, which they did. I kept my Jeep in the meantime. My new axle just arrived this Wednesday, 5 August -- so only about 2.5 week later. No rhyme or reason since some folks said they had to wait months for theirs. For what it's worth, I'm in Central Texas. I'm getting it installed this Monday.

Around 22 July, I installed the Z Automotive "Z Locker OEM" harness. I've only had it on for a few hundred miles, but have had ZERO issues. No lights, error messages, codes, etc., and this past weekend went 4-Low and use both front and rear lockers...again, zero issues. Seems like a great product so far, but its only been a few hundred miles on the harness.

I'll still get rear axle replaced since I'm under warranty, and will keep my fingers crossed. Regardless, the Z Locker harness will be in a ziplock bag in my glovebox just in case!
 

Eastcape14

Member
First Name
Steve
Joined
Jun 17, 2020
Threads
0
Messages
12
Reaction score
19
Location
St. Augustine, Fl
Vehicle(s)
2018 JLUR Rubicon
My JLU was in the shop for three days while they fixed a connection behind the dash because the service axle locker system light kept coming on. They said they had to take the whole dash out. It was fine for several days until I saw the warning light come on momentarily again. I drove it for a couple more weeks to see if it would come on again but did not see it happen. I just brought the Jeep in for an oil change and they found the code for service axle locker system. They replaced the front harness at no charge. I hope this fixes the problem. The dealer has been very nice about fixing this each time. They even gave me a rental the first time.
 

Reactor111

Well-Known Member
First Name
Garry
Joined
Oct 27, 2018
Threads
12
Messages
206
Reaction score
307
Location
Denver, NC
Vehicle(s)
2021 392
For the past couple months I have been getting the Service Locker message in the dash display. Mostly on cold start and it happens once or twice. Always clears in about 10 seconds. Locker control lights are dark during these events. The off road pages display are flashing to Locked (both front and rear) intermittently even with the dash message clear. This happens most all the time while driving. No rhyme or reason to when the off road indication occurs. Lockers are not locking when this occurs. When I use the locker controls, everything seems to work as they should. With both the front and rear indications on the off road display changing locked/unlocked at the same time Intermittently, how do I know if it’s the front or back sensor, or could this be another failure mode? 2018 JLUR , 20K miles , not lifted , stock gears. I’m sure there will not be any codes, but plan on seeing dealer soon.
 

Sponsored

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
For the past couple months I have been getting the Service Locker message in the dash display. Mostly on cold start and it happens once or twice. Always clears in about 10 seconds. Locker control lights are dark during these events. The off road pages display are flashing to Locked (both front and rear) intermittently even with the dash message clear. This happens most all the time while driving. No rhyme or reason to when the off road indication occurs. Lockers are not locking when this occurs. When I use the locker controls, everything seems to work as they should. With both the front and rear indications on the off road display changing locked/unlocked at the same time Intermittently, how do I know if it’s the front or back sensor, or could this be another failure mode? 2018 JLUR , 20K miles , not lifted , stock gears. I’m sure there will not be any codes, but plan on seeing dealer soon.
99% of the time it's the rear locker since the rear axle wears more than the front and produces the metal silt in the gear oil which causes the short. I would get into the dealer asap and get it on the books. In the meantime you'd be wise to simply unplug the harness from the rear axle. It will take you all of 30 seconds and ensure that the axle won't engage on you. Myself and another member both had our axle lockers engage on us while driving in 2H.
 

Cindyb13

Member
First Name
Cindy
Joined
Jul 14, 2020
Threads
0
Messages
10
Reaction score
3
Location
02630
Vehicle(s)
2020 Jeep Wrangler Rubicon Recon
My dealer called me Friday, left a message, said my new axle assembly is in. I plan to call them to find out if it's a revamped assembly, or another of the same. I don't want to go through this again. I thought they were on back-order til late September. Anyone know? And then today, my Service/start stop warning light came on. Ugh. I found the thread on that one. I'm beginning to regret buying this vehicle!! Definitely would not recommend to anyone. I have under 3k, miles.
 

SantiamJp

Member
First Name
Eli
Joined
Mar 10, 2018
Threads
1
Messages
24
Reaction score
5
Location
Oregon
Vehicle(s)
2000 TJ; 1996 XJ; 2006 XK
Oil on plug and my debacle so far.

I have ~67K on our 2018 JLUR. We installed 5.13 gears at around 15K miles. Took the Jeep to Rubicon Trail and Fordyce Creek (just some light wheeling, right?). Right before that, I installed the Metalcloak diff covers and put the recommended gear oil in for the tow pckage.

When we left the trail, the rear locker light started blinking in 2H and on the offroad page on the dash, showed the rear axle locked.

I unplugged the rear diff plug and it was covered in gear oil. Sprayed brake cleaner on it, cleaned it off, let it dry. Still... blinking light.

It locked up briefly, fortunately at low speed.

About halfway home to Oregon, it went off. We camped at Crater Lake and while backing the trailer up a hill to the camp spot, it came back on. Hasn’t turned off.

zAutomotive had the fix to me two days later (because they’re awesome like that). It fixed the issue. But I still want it to work the right way.

Here are my questions: those getting new axles, will the dealer upgrade or put your gears back in if you have re-geared?

Also, has the dealer tried to replace the sensor? It looks like they make a sensor for it, but I cannot tell if that’s the fix.
 

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
Oil on plug and my debacle so far.

I have ~67K on our 2018 JLUR. We installed 5.13 gears at around 15K miles. Took the Jeep to Rubicon Trail and Fordyce Creek (just some light wheeling, right?). Right before that, I installed the Metalcloak diff covers and put the recommended gear oil in for the tow pckage.

When we left the trail, the rear locker light started blinking in 2H and on the offroad page on the dash, showed the rear axle locked.

I unplugged the rear diff plug and it was covered in gear oil. Sprayed brake cleaner on it, cleaned it off, let it dry. Still... blinking light.

It locked up briefly, fortunately at low speed.

About halfway home to Oregon, it went off. We camped at Crater Lake and while backing the trailer up a hill to the camp spot, it came back on. Hasn’t turned off.

zAutomotive had the fix to me two days later (because they’re awesome like that). It fixed the issue. But I still want it to work the right way.

Here are my questions: those getting new axles, will the dealer upgrade or put your gears back in if you have re-geared?

Also, has the dealer tried to replace the sensor? It looks like they make a sensor for it, but I cannot tell if that’s the fix.
Most likely the dealer won't touch your axle because you re-geared so you will be on your own, at least that is what happened to me and a few others. There is one woman on here who re-geared and the dealer said they will put her old gears in the new axle put she will have to pay the labor on that. Personally I wouldn't want the dealer touching my gears, I would want a specialty shop who does A LOT of gear doing that job.
The dealers are not doing ANYTHING other than swapping out the axles. FCA will not let them open the axles up and do any diagnostic work on it.
The logical solution is to replace the sensor with a new one that hopefully won't leak. This is what I did... I took the sensor out of my wife's axle since she has a Sahara that we put Rubi axles on and she does not need that sensor. This took me all of 40 mins to do and voila problem is fixed.
Had I not had that axle to pull the part from I would have bought the Tazer part and installed it.
You have your solution, you fixed it with the Tazer. The solenoid that is failing is the solenoid that reads the state of the locker. The Tazer harness essentially sends a correct state constantly to the computer so the computer is happy.
When the solenoid gets that gear oil in it it goes berserk and starts shorting out and then in the worse case scenario (like happened to me and another guy) it actually locks the locker while you are driving in 2H and WILL NOT unlock it. Fun times that day.
 

SantiamJp

Member
First Name
Eli
Joined
Mar 10, 2018
Threads
1
Messages
24
Reaction score
5
Location
Oregon
Vehicle(s)
2000 TJ; 1996 XJ; 2006 XK
You have your solution, you fixed it with the Tazer. The solenoid that is failing is the solenoid that reads the state of the locker. The Tazer harness essentially sends a correct state constantly to the computer so the computer is happy.
So with the Tazer, do I have to worry about the sensor engaging the locker? If feels like a cover-up and maybe not tackling the issue. I’m just worrying if it is shorting, will the actual pin that engaged the locker eventually short?

My dealer admitted the sensor can be ordered and would swap it, but I keep hearing these horror stories.
 

Sponsored

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
So with the Tazer, do I have to worry about the sensor engaging the locker? If feels like a cover-up and maybe not tackling the issue. I’m just worrying if it is shorting, will the actual pin that engaged the locker eventually short?

My dealer admitted the sensor can be ordered and would swap it, but I keep hearing these horror stories.
For starters your dealer is wrong. @wibornz has crawled straight up his dealer's and Dana/Spycer's arse wanting that solenoid and Dana won't even sell it to him even though they have them. They are not allowed since it is a FCA part and FCA won't sell them.

The setup is simple, there are two solenoids; the first is a simple on/off that engages the locker. In my wife's Jeep, since she is running these axles in an aftermarket situation, that is the only solenoid she uses. The second solenoid is what I will call the "state" solenoid and it tells the computer what is the state of the locker. Basically it's a feedback loop to the computer and locker control switch to tell it the state of the locker. When it goes bonkers the computer doesn't know what to do and throws the code OR in worse case like happened to me it decides to lock the locker in 2H.
IF I understand correctly (and I would reach out to Z Automotive for more info if you want), the Tazer harness tells the computer the locker is OK thereby allowing it to engage/disengage properly.
Call it cheating call it ingenious call the factory setup bull$hit. At the end of the day FCA knows about this and clearly has their head so far up their arse about it since they aren't really doing anything to fix it. I mean an aftermarket company came to the party late and had a solution created and on the market in a couple of months but FCA is still swapping axles and watching the failures repeat.
Funny thing is the SAME EXACT AXLES are on my wife's Jeep with ZERO problems because we have hers wired to the AUX switches. It's the little red locker control in the Rubi that cares about that stupid solenoid.
 

fixbroke

Well-Known Member
Joined
Mar 18, 2020
Threads
6
Messages
58
Reaction score
74
Location
California
Vehicle(s)
2020 JTR
The setup is simple, there are two solenoids; the first is a simple on/off that engages the locker. In my wife's Jeep, since she is running these axles in an aftermarket situation, that is the only solenoid she uses. The second solenoid is what I will call the "state" solenoid and it tells the computer what is the state of the locker.
Good explanation of how it works, but the pedant in me insists we clarify that there's only one solenoid. The solenoid is the magnetic actuator that physically moves the locker plate, while the other component is a hall sensor that provides the feedback.
 

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
Good explanation of how it works, but the pedant in me insists we clarify that there's only one solenoid. The solenoid is the magnetic actuator that physically moves the locker plate, while the other component is a hall sensor that provides the feedback.
Thanks for clarifying!
 

mgroeger

Well-Known Member
First Name
Mike
Joined
Feb 1, 2018
Threads
150
Messages
5,454
Reaction score
7,844
Location
Hurricane, UT
Vehicle(s)
2021 JLUR 2.0T, 1991 YJ rock crawler
Occupation
I make microchips for a living.
Vehicle Showcase
1
Good explanation of how it works, but the pedant in me insists we clarify that there's only one solenoid. The solenoid is the magnetic actuator that physically moves the locker plate, while the other component is a hall sensor that provides the feedback.
Thanks for being all sophisticated Mr. Pedant. Had to go and google that word.
Sponsored

 
 



Top