F34 fuse = loss of power steering, among other things

dustdriver

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Just back from a desert trip and had a little issue to share. First day driving was just slow, rough roads, nothing crazy. Pulled into campsite in 2WD, with everything working normally. While getting the Jeep into position, the instrument panel starts to light up: ESC, swaybar, and power steering warning indicators all came on, and all 3 systems lost. Restarted everything, same situation. Let it sit overnight, tried again in the morning, no change.

At this point, I'm suspecting a battery issue, because just a day earlier when I started the Jeep in the morning I got the "battery saver mode on" message, which disappeared in about 5 minutes. I'd also read several other threads about battery issues being preceded by various dash light symptoms. But after watching the voltmeter (thanks, hutchman for the idea), the battery voltage was normal, everything appeared to be charging just fine.

This makes me suspect it might be a fuse issue, so I raise the hood and carefully begin reading the tiny fuse box labels for anything might have something to do with all 3 of those systems... and what did I find? A blown F34 fuse.

F34 ESC/EHPS/SBCM WAKE UP 10A

(For anyone who doesn't know, that stands for "Electronic Stability Control/Electric Hydraulic Power Steering/Smart Bar Control Module".)

Replaced the fuse, problem solved! Spent the next 4 days exploring the desert without any issues whatsoever.

I still want to know WHY the fuse was blown in the first place, and will have the dealer check it out. Maybe someone else already knows the answer?

Just FYI, might save someone else a lot of stress. I wasn't looking forward to having to figure out how to get a battery to the Jeep or the Jeep to a dealership, given my remote location and poor cell service.

(BTW, if you haven't done so already, take some photos of the fuse box labels so you can read them easier even when it's a dark and stormy night.)

F34_fuse_ 1.jpg


F34_fuse_ 2.jpg
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Rhinebeck01

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Just back from a desert trip and had a little issue to share. First day driving was just slow, rough roads, nothing crazy. Pulled into campsite in 2WD, with everything working normally. While getting the Jeep into position, the instrument panel starts to light up: ESC, swaybar, and power steering warning indicators all came on, and all 3 systems lost. Restarted everything, same situation. Let it sit overnight, tried again in the morning, no change.

At this point, I'm suspecting a battery issue, because just a day earlier when I started the Jeep in the morning I got the "battery saver mode on" message, which disappeared in about 5 minutes. I'd also read several other threads about battery issues being preceded by various dash light symptoms. But after watching the voltmeter (thanks, hutchman for the idea), the battery voltage was normal, everything appeared to be charging just fine.

This makes me suspect it might be a fuse issue, so I raise the hood and carefully begin reading the tiny fuse box labels for anything might have something to do with all 3 of those systems... and what did I find? A blown F34 fuse.

F34 ESC/EHPS/SBCM WAKE UP 10A

(For anyone who doesn't know, that stands for "Electronic Stability Control/Electric Hydraulic Power Steering/Smart Bar Control Module".)

Replaced the fuse, problem solved! Spent the next 4 days exploring the desert without any issues whatsoever.

I still want to know WHY the fuse was blown in the first place, and will have the dealer check it out. Maybe someone else already knows the answer?

Just FYI, might save someone else a lot of stress. I wasn't looking forward to having to figure out how to get a battery to the Jeep or the Jeep to a dealership, given my remote location and poor cell service.

(BTW, if you haven't done so already, take some photos of the fuse box labels so you can read them easier even when it's a dark and stormy night.)

F34_fuse_ 1.jpg


F34_fuse_ 2.jpg
@dustdriver

I recently posted that taking a pic of inner fuse cover with fuse locations and keeping on the smartphone was a wise move...

Also, another guy .... a couple of years ago posted similar.... His F34 had not been pushed down enough at the factory and it had worked its way up... so no longer doing the deed and his JL displayed the same symptoms...

Perhaps your F34 was loose and well, blew as you/it were bouncing around so to speak.

Thanks for coming here and posting about your experience.. For sure, doing so is helpful to other owner's.

I for one remember this type of thing I read here... You post refreshed my memory..
 
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dustdriver

dustdriver

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It's been about 4 months since the OP, here's a relevant update:
Since replacing that F34 fuse, there have been no repeats... until now!
Yesterday, same exact symptoms reappeared out of nowhere: first the ESC goes out, then the Swaybar control, both with dash lights and warnings, one right on top of the other.

As long as the Jeep is still running, that's the end of it. But if I turn the engine off (or the ESS shuts it off for me), when I restart the engine, I lose POWER STEERING!
I can live for awhile with no ESC and no swaybar disconnect, but not without power steering.

The problem seems to be getting worse this time. After replacing the F34 fuse again, it blew the next one, and the next, and the next, etc. all within a minute of starting and driving again. So as it sits now, if I want to drive anywhere I have to first put in a fresh F34 fuse first, and not turn the engine off.

Taking it into the dealer in 2 weeks. I'll let you know the outcome.
 

el_guapo

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Having the same issue, blew 2 fuses so far on my 21 jlur 392. Hoping to get off-road this weekend but not if this isn't fixed.

@dustdriver - any updates for us?
 

mwilk012

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Fuse F34 is on a fairly simple circuit, powers straight from the PDC to the power steering pump. Note that is is a control circuit, not motor power.
 

GSLSE21B

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Popped this after ripping a boulder up through the front right wheel opening .
 

el_guapo

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Having the same issue, blew 2 fuses so far on my 21 jlur 392. Hoping to get off-road this weekend but not if this isn't fixed.

@dustdriver - any updates for us?
I'll answer my own question...just heard back from dealership, they're saying it's a bad cluster. Sounds bad in and of itself, but the part will take 3 months to get in given the constraints on supply chain. So basically undrive-able for another 3 months.

The instrument panel always worked, but somehow I guess they believe it's shorting out the F34 fuse.

Crazy...
 

mwilk012

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I'll answer my own question...just heard back from dealership, they're saying it's a bad cluster. Sounds bad in and of itself, but the part will take 3 months to get in given the constraints on supply chain. So basically undrive-able for another 3 months.

The instrument panel always worked, but somehow I guess they believe it's shorting out the F34 fuse.

Crazy...
What reason do they have to believe that?

https://www.jlwranglerforums.com/JL-Wiring-Diagrams/FUSES_RELAY---RUN_START.pdf

This diagram shows Fuse 34 going to exactly three things. The Instrument cluster is on Fuse 41.

Just realized you are not the OP and you didn't list which fuse was blown. I assume yours is probably 41...
 
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el_guapo

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What reason do they have to believe that?

https://www.jlwranglerforums.com/JL-Wiring-Diagrams/FUSES_RELAY---RUN_START.pdf

This diagram shows Fuse 34 going to exactly three things. The Instrument cluster is on Fuse 41.

Just realized you are not the OP and you didn't list which fuse was blown. I assume yours is probably 41...
No, I lost power steering / ESC / sway bars, and saw 34 was blown. Replaced it and that fixed the problem until it blew again. Why DLR thinks the cluster is the problem, not sure, particularly with your findings...
 

mwilk012

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No, I lost power steering / ESC / sway bars, and saw 34 was blown. Replaced it and that fixed the problem until it blew again. Why DLR thinks the cluster is the problem, not sure, particularly with your findings...
You should ask them what they found to draw that conclusion. It’s simply unacceptable for the vehicle to not be drivable for months without a good reason.
 
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dustdriver

dustdriver

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Having the same issue, blew 2 fuses so far on my 21 jlur 392. Hoping to get off-road this weekend but not if this isn't fixed.

@dustdriver - any updates for us?

Sorry, haven't been online much lately.
It turned out to be a short in a wire that was rubbing against something up front. Apparently when I had the winch installed at a local 4x4 place, they accidentally pushed a wiring harness into contact with another part. Over time it wore through the wiring housing and made intermittent contact with metal enough to short out.

Dealer found it and it was an easy fix, but they did have to drop skid plates, etc. to find it, splice it, and re-route the harness out of the way. For me it was a good reminder to let a (trusted) dealership install things whenever possible so it will be covered (hopefully under warranty) if something goes wrong.

Good luck!
 
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