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Service 4WD indicator during (brief) beach trip

eck

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I went this past Saturday to drive on the beach at Fort Fisher as I have done several times with my Jeep. There is a sand "road" about 1/2 mile long that leads out to the beach. Maybe three minutes after I left the pavement, before even reaching the beach itself, I suddenly lost 4WD while in 4HI and the "Service 4WD" indicator lit on the dash. No amount of engaging/disengaging, turning the Jeep on/off would make it engage. So in the end, we towed it back to the parking lot with another Jeep and just walked to the beach.

After a few hours at the beach, there was no longer any errors on the dash, and I just left it in 2H to get home without issue.

After getting home, I ran it through the transfer case positions a few times, and everything was (and still is) working 100% as expected.

I have an appointment scheduled with the dealer on Monday to have it looked at. I'll update after with what they find out.

In the mean time, I used this as an opportunity to buy a code reader to check on this and other future problems.

Here's what the Jeep has stored:

C0501, C0507, C050D, C0513 - Left Front/Right Front/Left Rear/Right Rear Wheel Speed Sensor Range/Performance, respectively

C1045 - Rear Tone Wheel Performance

C147B - Front Axle Disconnect Sensor Circuit Performance

C1477 - Transfer Case Clutch Over Temperature

The clutch in particular has me worried, since it was engaged for such a short time. Something to consider for anyone considering the Selec-Trac transfer case.
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DenaliDan

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Interesting. Hopefully it's just a bad temp sensor. Curious to see how it turns out.
 
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eck

eck

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hey @eck, were you in 4H Auto or 4H Part-Time? and what was the temperature that day? keep us posted, thanks
4H Part-time. Temperature was low to mid 80s. I've done the same trip twice earlier in the summer when it was easily in the 90s.

My understanding is that there a mechanical sleeve that engages to lock the transfer case into 4HI Part-Time and take the clutch pack out of the equation. My best guess is that sleeve didn't engage all the way for some reason and was allowing a lot of clutch slip so it overheated very quickly.
 
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eck

eck

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Dropped the Jeep off, argued for five minutes with the service writer about how 4WD is supposed to work. He said 4HI Part Time is not supposed to lock the transfer case, only 4LO does. 4HI PT only locks when it detects slip. So then I asked him what 4HI Auto was for and how it was any different. He said it's only for roads but couldn't explain how they were any different.

:facepalm:

I have very low expectations now, hopefully the guys with the wrenches have more sense.
 

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Dropped the Jeep off, argued for five minutes with the service writer about how 4WD is supposed to work. He said 4HI Part Time is not supposed to lock the transfer case, only 4LO does. 4HI PT only locks when it detects slip. So then I asked him what 4HI Auto was for and how it was any different. He said it's only for roads but couldn't explain how they were any different.

:facepalm:

I have very low expectations now, hopefully the guys with the wrenches have more sense.
Hi eck,

Please be sure to keep us updated on your dealer's findings. If our team can be of any additional assistance regarding your situation, we would be happy to help. We are just a private message away.

Mark
JeepCares
 
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eck

eck

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Update after speaking with the service advisor:

Jeep is ready to pick up. Jeep "didn't cooperate" to figure out why it failed. No available service bulletins that describe the problem.

Official diagnosis: Don't use 4H.

Wonderful.

:headbang:
 

jlroman2

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Did the service 4WD light ever come back? Mine is on after getting lift and 35s installed.
 
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eck

eck

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Did the service 4WD light ever come back? Mine is on after getting lift and 35s installed.
Nope it hasn't come back on yet, but I haven't had it offroad so far. I have cycled through all the transfer case positions *a lot* while going dead straight on pavement and everything seems ok. Planning to go do some trails maybe next weekend so we'll see how it goes.
 

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Any update on this? My serv4wd lift comes on after being in 4WD for a bit but no codes. Canā€™t find much about it.
 
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eck

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Any update on this? My serv4wd lift comes on after being in 4WD for a bit but no codes. Canā€™t find much about it.
I've had it out to Uwharrie a few times on the trails, and everything has functioned fine there. Haven't had a chance to get back to the beach yet this year, but we're probably going to make a trip one day this coming week. I'll report back how it goes in the sand.
 
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eck

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I've had it out to Uwharrie a few times on the trails, and everything has functioned fine there. Haven't had a chance to get back to the beach yet this year, but we're probably going to make a trip one day this coming week. I'll report back how it goes in the sand.
Update!

Went yesterday, zero issues on the beach.
 

Az-jewel

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Any update on this? My serv4wd lift comes on after being in 4WD for a bit but no codes. Canā€™t find much about it.
Thanks for the update @eck!

i took mine to the dealership and evidently when the off road shop reassembled my axle, after replacing my gears, they put the FAD actuator inside the axle collar and messed up the gasket too. (? Iā€™m sure Iā€™m not sagii that right) According to the dealer it should have been kept outside the axle collar (I know very little about it but have seen photos of the FAD connection definitely outside the axle). Long story shorter, but the time I called the dealer back to let him know Iā€™d be taking it back to the off road shop who messed it up, they had already done the repair!
negotiated it down to $100 out the door (from $340). I want the off road shop to reimburse me but doubt they will, this is the second mistake Iā€™ve found after the install and Iā€™m both frustrated and wary of letting them ā€œfixā€ anything else. Iā€™ll likely eat the $100 for the peace of mind.
 

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I went this past Saturday to drive on the beach at Fort Fisher as I have done several times with my Jeep. There is a sand "road" about 1/2 mile long that leads out to the beach. Maybe three minutes after I left the pavement, before even reaching the beach itself, I suddenly lost 4WD while in 4HI and the "Service 4WD" indicator lit on the dash. No amount of engaging/disengaging, turning the Jeep on/off would make it engage. So in the end, we towed it back to the parking lot with another Jeep and just walked to the beach.

After a few hours at the beach, there was no longer any errors on the dash, and I just left it in 2H to get home without issue.

After getting home, I ran it through the transfer case positions a few times, and everything was (and still is) working 100% as expected.

I have an appointment scheduled with the dealer on Monday to have it looked at. I'll update after with what they find out.

In the mean time, I used this as an opportunity to buy a code reader to check on this and other future problems.

Here's what the Jeep has stored:

C0501, C0507, C050D, C0513 - Left Front/Right Front/Left Rear/Right Rear Wheel Speed Sensor Range/Performance, respectively

C1045 - Rear Tone Wheel Performance

C147B - Front Axle Disconnect Sensor Circuit Performance

C1477 - Transfer Case Clutch Over Temperature

The clutch in particular has me worried, since it was engaged for such a short time. Something to consider for anyone considering the Selec-Trac transfer case.

I didn't know it until recently, but apparently the AWD/Selec-Trac style t-cases that Jeep and Ram use are clutched style t-cases REGARDLESS of which mode you are in. In other words, even if you go to 4-high for full 50/50 lock, the power split is still being controlled via clutching.

Formerly I had thought that only the Full-Time/Auto setting used a viscous coupling or clutched coupling to allow some slippage front to rear, and the Part-Time settings were mechanically locked. I was wrong.
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