JLU Diesel - Electrical Nightmares (Problems - Electrical systems failures - Wiring harness)

kotam

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2021 JLU Diesel Rubicon
Now on the third trip to the shop with the 2021 JLUD Rubicon, factory tricked out w/ about 12xxx miles.
Bumpers, Stealth wench, Rock Slider running board steps. No other accessories.

10+k miles as a seemingly fantastic vehicle - THEN...
The Vehicle started exhibiting problems when attempting to start it as follows:
a. Shifter Locks in Park (as it's already there) and ALL Lights PRNDM light up bright orange.
b. Ignition button will not move (switch) from RUN position.
c. Dash displays several diag messages like:
"Service Sway Bar locks"
"Service transmission. Continue in D. Do not shift or turn engine off. (It's in park)
"Vehicle Not in Park." (It's locked in park)
Check Engine light
Traction Control light on (traction control is off)
d. All responses to operator input are ignored - ignition button, shifter locked into park position, brakes go to near floor, vehicle cannot be turned off or moved (without pulling transmission unlock strap under console)

The get-off-the-side-of-the-road remedy to unlocking the syndrom is apparently reset by removing the far terminal connection on the side of the fuse box which disconnects both batteries. System will reset and usually allow a start - BUT ALL ERROR CODES ARE ERASED WHEN THE BATTERY IS DISCONNECTED AND SHOP CANNOT SEE CODES. "Looks like their "we can't find any error codes" excuse is designed right in using volatile memory to store errors. In most cases it worked on the first or second attempt - other attempts to reset and start took several disconnect/start attempts with it not starting for the first several trys.

Once the battery is disconnected and the vehicle is restarted, it runs fine, except:
After the vehicle restarts, we note a few irregularities that are concerning. (Dumb)-ASS (auto start/stop) system fails to "enable" most of the time one would expect to see it work.
Key Fob will trigger remote start but vehicle (even with 2 normal horn beeps) will not start. It appears to be that remote start works about 50% of the attempts.
Performance is good as usual. Transmission acts normal.

On the way to dealership for the 2nd time, we were sitting in traffic at stop light when vehicle rev'ed quite sharply, putting us within inches of hitting the Acura Mdx in front of us and making that driver "quite irritable." We waited for large gap in traffic and proceeded to shop. The engine idled backed down and ran as normal afterwards and for a few blocks to the shop where it was turned off.

Now 3 trips to the shop with "we can't find any problems" and countless hours on the phone with FCA put us in the position of preparing documents in prep of Lemon prosecution. Shop tells us they are seeing like events happen on several vehicles (3 Jeeps now) and other FCA vehicles. TSB's note that the placement of the wiring harness may subject to penetration/cutting by hardware contact in a few locations, burn-through where wires are mounted too close to hot components, and the wires plugged into the sockets of the communications hub (behind the glove box) should be "wiggled" to see if that corrects problem. (Of all vehicles, the one advertised as a tough off-road vehicle is overly sensitive to vibration!! ??)

Today, we picked it up from dealership with the same "can't find anything wrong" story and it failed again about 3 hours later. This time, we called the service mgr and left the JL in fail state with the above symptoms in place, not disconnecting anything to reset it and allow start. Service folks came to where vehicle was located and captured PCM/ECU codes and state that codes point to both Shifter and PCM failures. Vehicle was placed on tow bed truck and taken to dealership for further diags/repair.

The JLUD uses a normal 600A AGM battery for cabin and supplemental power while the engine is run on a 200A motorcycle battery mounted under the 600A car battery. Removing the large battery will still allow complete operation of the engine. ?My walker mower has a larger battery than my diesel Jeep... How is this a good idea?

Reading lots of forum posts and articles, any low voltages seems to be a culprit with these systems so the batteries were closely examined by other shop where we found the small battery would not load past about 60A - although the vehicle started great on it. It was replaced with a 240A AGM - the largest battery we could get in the hole. The factory 600A AGM battery tested very well. All battery considerations were addressed on the first go-around.

I've read thousands of posts but have not seem one that demonstrates what we're seeing here; and apparently what local shop (Amarillo, Texas) is seeing on a few other vehicles. I asked dealership "what one does with a problem like this" and got a very interesting response indicating that FCA will not replace any parts until a diag code tells them to - just keep bringing it to the shop until it qualifies for a buy-back (Lemon) and get your money back.

I post this to inquire as to others seeing like problems with the JL?

Thanks for reading ( and putting up with my disappointment & frustration).

Kotam

p,s, We also note that the Jeep will not take on a minor pavement imperfection that our Prius glides right over without bottoming on the stops. Anyone heard of them putting the gas-version springs in the diesel units - which are about 400lbs heavier?
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timannnn6

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Couple of things to check. Fuses in engine comp passenger side, make sure all are pressed in firmly. Most find half or more are loose.

Next, saw a vid of someone that had major electrical issues with diesel. They found that wiring underneath snakes along underside passenger side of engine, and is very close to exhaust. Starts rubbing up close and burns through. Check all looms underneath on both sides.

Good luck.
 

aldo98229

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Welcome to the forum!

Sounds like Prius is the way to go.

Good luck.
 

SaltyWet

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Now on the third trip to the shop with the 2021 JLUD Rubicon, factory tricked out w/ about 12xxx miles.
Bumpers, Stealth wench, Rock Slider running board steps. No other accessories.

10+k miles as a seemingly fantastic vehicle - THEN...
The Vehicle started exhibiting problems when attempting to start it as follows:
a. Shifter Locks in Park (as it's already there) and ALL Lights PRNDM light up bright orange.
b. Ignition button will not move (switch) from RUN position.
c. Dash displays several diag messages like:
"Service Sway Bar locks"
"Service transmission. Continue in D. Do not shift or turn engine off. (It's in park)
"Vehicle Not in Park." (It's locked in park)
Check Engine light
Traction Control light on (traction control is off)
d. All responses to operator input are ignored - ignition button, shifter locked into park position, brakes go to near floor, vehicle cannot be turned off or moved (without pulling transmission unlock strap under console)

The get-off-the-side-of-the-road remedy to unlocking the syndrom is apparently reset by removing the far terminal connection on the side of the fuse box which disconnects both batteries. System will reset and usually allow a start - BUT ALL ERROR CODES ARE ERASED WHEN THE BATTERY IS DISCONNECTED AND SHOP CANNOT SEE CODES. "Looks like their "we can't find any error codes" excuse is designed right in using volatile memory to store errors. In most cases it worked on the first or second attempt - other attempts to reset and start took several disconnect/start attempts with it not starting for the first several trys.

Once the battery is disconnected and the vehicle is restarted, it runs fine, except:
After the vehicle restarts, we note a few irregularities that are concerning. (Dumb)-ASS (auto start/stop) system fails to "enable" most of the time one would expect to see it work.
Key Fob will trigger remote start but vehicle (even with 2 normal horn beeps) will not start. It appears to be that remote start works about 50% of the attempts.
Performance is good as usual. Transmission acts normal.

On the way to dealership for the 2nd time, we were sitting in traffic at stop light when vehicle rev'ed quite sharply, putting us within inches of hitting the Acura Mdx in front of us and making that driver "quite irritable." We waited for large gap in traffic and proceeded to shop. The engine idled backed down and ran as normal afterwards and for a few blocks to the shop where it was turned off.

Now 3 trips to the shop with "we can't find any problems" and countless hours on the phone with FCA put us in the position of preparing documents in prep of Lemon prosecution. Shop tells us they are seeing like events happen on several vehicles (3 Jeeps now) and other FCA vehicles. TSB's note that the placement of the wiring harness may subject to penetration/cutting by hardware contact in a few locations, burn-through where wires are mounted too close to hot components, and the wires plugged into the sockets of the communications hub (behind the glove box) should be "wiggled" to see if that corrects problem. (Of all vehicles, the one advertised as a tough off-road vehicle is overly sensitive to vibration!! ??)

Today, we picked it up from dealership with the same "can't find anything wrong" story and it failed again about 3 hours later. This time, we called the service mgr and left the JL in fail state with the above symptoms in place, not disconnecting anything to reset it and allow start. Service folks came to where vehicle was located and captured PCM/ECU codes and state that codes point to both Shifter and PCM failures. Vehicle was placed on tow bed truck and taken to dealership for further diags/repair.

The JLUD uses a normal 600A AGM battery for cabin and supplemental power while the engine is run on a 200A motorcycle battery mounted under the 600A car battery. Removing the large battery will still allow complete operation of the engine. ?My walker mower has a larger battery than my diesel Jeep... How is this a good idea?

Reading lots of forum posts and articles, any low voltages seems to be a culprit with these systems so the batteries were closely examined by other shop where we found the small battery would not load past about 60A - although the vehicle started great on it. It was replaced with a 240A AGM - the largest battery we could get in the hole. The factory 600A AGM battery tested very well. All battery considerations were addressed on the first go-around.

I've read thousands of posts but have not seem one that demonstrates what we're seeing here; and apparently what local shop (Amarillo, Texas) is seeing on a few other vehicles. I asked dealership "what one does with a problem like this" and got a very interesting response indicating that FCA will not replace any parts until a diag code tells them to - just keep bringing it to the shop until it qualifies for a buy-back (Lemon) and get your money back.

I post this to inquire as to others seeing like problems with the JL?

Thanks for reading ( and putting up with my disappointment & frustration).

Kotam

p,s, We also note that the Jeep will not take on a minor pavement imperfection that our Prius glides right over without bottoming on the stops. Anyone heard of them putting the gas-version springs in the diesel units - which are about 400lbs heavier?
I've actually had that happen once on my JLURD, I remember I had the jeep on ACC and locked the doors thinking it was going to be a short trip in the store.

It took longer then expected and when I came back out it had the same thing you are describing, couldn't start, PRND all lit up orange, and multiple warning on the dash.

Luckily I wasn't in a rush to go anywhere so I was searching up on the forums. Nothing came up and I was about to call my buddy to bring some tools to do a hard reset.

As I was just hanging up the phone, the jeep rebooted everything. My hood was open and I was near the fuse box area, so I heard some relays clicking. (and yes I have had all the fuses clicked in a long time ago) Went to start it up and it just fired up like nothing happened before.

I believe it happened in April or May and it haven't came back since. Right now I will occasionally get the Serv4wd, abs, and the TC light out of nowhere or going through some rough dirt road fast or lost traction while turning. Most of the times the lights will go off within a couple minutes. Very strange.

I do believe it could be the fuses for serv4wd abs and TC lights. I've checked the fuses once after the lights came and 2 of the fuses were lose. After fixing that and restarted the jeep, the lights turned off after 30 seconds and hasn't came back since.
 
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kotam

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Roger
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Location
Texas Panhandle
Vehicle(s)
2021 JLU Diesel Rubicon
Hi All
12xxx miles - great motor so far, good mechanics so far, great look.. That's ALL!

Thanks SO much for the input and sharing your experiences & links to like problems.
Had a few Jeeps, Cj, Yk, TJ-rubicon, 2Jk-Rubicons's, 1 JLUD. - All getting worse with generations.

In reading several other sites (carcomplaints, etc) it appears to me that our experience is more and more common and FCA has come to no workable resolution while the dealerships appear also appear to have no actual solutions to the problems. The folks at the local dealership tell me that they are having like problems happening all over the FCA products (Ram, Chrysler, Jeep) with no real means to correct the problems to the point of having any confidence in their products. Their response: Keep bringing it in until FCA has to buy it back.

We're hearing of 5 vehicles at a mid-sized town dealership having like problems while they continue to sell them and cash the checks while stating no clue how to address them.. It what world does this demonstrate a reputable product or service response. it appears that there those that have few to little problems reading the other threads - which represents what we were told we were buying while not proving to be so. IMO: There should be a "disclosure" law that strictly applies to sales and shops with large penalties not informing clients of messes like this.

It's a true shame for a purebred vehicle turn into such a delicate, unreliable, high-dollar product and money maker for FCA while the problems continue on and dangerous occurrences of the car stepping on the gas (like ours) being reported are apparently excused or ignored while the shops just send em right back to the street under the cloud of "we can't find anything wrong" or "it's not reporting any error codes" other then lots of (?over 50?) "communications errors." Someone with a computer, avionics, or telecom background do the math for me - maybe the error IS communications??????. I'll look forward to the reading about the lawsuits while we no longer have and would NEVER consider another current-day FCA product - of any make or style - for ANY reason.

That said, tuesday is the end of our Jeep days as the $60,000+ 2021 Rubicon gladly leaves the driveway for good. Per suggestion of prior commends to this post, we're keeping the Prius and moved today from Jeep to 4-Runner TRD - the only thing from the Jeep staying being bad memories and the wench.. The reality of the product makes it one we never care to own again and a maker we don't have time waste on, regardless of the cool factor and modifiability. Love the Jeep idea, adore the outdoor folks, admire the serious climbers but the reality for us is Goodbye FCA-Jeep!
 
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