Electronics Issue in the Outback

[desert runner]

I'm looking for some advise from the electric/electronic experts on the forum.

A week back I was stranded in the Maze, a part of Canyonlands in Utah considered one of the most remote areas in the lower 48 states. Here is what happened:

We were camping in the Dollhouse area of the Maze for two days, during which the fridge was connected to my main battery and drained it. I had parked the vehicle in 4L.

No problem (I thought) and pulled out my Micro-Start XP-10 pack from Antigravity Batteries. Disappointingly, the XP-10 could not start the engine, It did jolt the starter a bit, but not enough to start it.

So I grabbed the jumper cable to start the engine with the help of our second Jeep, pressed the start button.

Something happened at this point, and the electronics ended up in an undefined state:

• The lights indicating Park, Drive, Reverse, Neutral next to the automatic shifter all lit up in yellow.
• The start button indicated RUN, and pressing it again did nothing
• A solenoid in the engine compartment was humming/hissing, potentially the fuel pump?
• The following error was displayed on the dash:

The electronics appeared to assume that the engine was running, it wasn't. It also assumed that I could shift into D, which was not possible.

We came to the conclusion that we need to reset the system, but how?

I could not find any information in the manual on how to do this. Jeep care was not reachable on a Sunday.

We finally decided to start pulling fuses one by one. We began at the lower right, fuse F10 (description is KIN/RF HUB/ESCL, see yellow arrow below) and immediately hit the jackpot:

• the lights on the dash went out,
• the solenoid went quiet.

We pushed the fuse back in and everything looked normal: no error message, shifter positions lit in white as they should. With the jumper cables connected I pushed the start button and the the engine started. We made it out of the Maze safely .

So here are my questions

• How did the electronics end up in a state thinking that there was a transmission problem and that the engine was running? Was it because the Jeep had been parked in 4L?
• What is the proper way to reset the electronics?
• What exactly does fuse F10 (KIN/RF HUB/ESCL) do?

Any input is greatly appreciated.

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[Mad Hatter]

Ouch, Wow, and Glad you figured a way to get back!

Will follow this thread to learn more...

 

[mwilk012]

Sounds like you should have disconnected the batteries.

 

[desert runner]

Sounds like you should have disconnected the batteries.

Indeed we disconnected the main battery in an attempt to reset. However, the second battery must have kept the system alive, so the reset did not work that way. We did not disconnect the second battery.

 

[HoundDude]

your camping trip sounds amazing, I hope I get to see a place like that before i die.

I think you'll find all the smart people are in this thread (especially the OP):
https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/

 

[mwilk012]

Indeed we disconnected the main battery in an attempt to reset. However, the second battery must have kept the system alive, so the reset did not work that way. We did not disconnect the second battery.

Yea, you have to disconnect both.

 

[Rploaded]

This is an ideal time for a tazer reboot if you have one. This is one reason I like the 2.0 you disconnect the battery and it’s dead. The 3.6 you have another one to deal with.

 

[D60]

This is an ideal time for a tazer reboot if you have one. This is one reason I like the 2.0 you disconnect the battery and it’s dead. The 3.6 you have another one to deal with.

There's just two studs on the right inner fender you disconnect to kill the whole system (edit: in addition to main batt neg). I "arrowed" mine w an Inkzall to help w my CRS when welding on the rig.

A minor inconvenience for sure, but far from insurmountable

 

[mwilk012]

You can pull the ESS battery leads right off of the main battery, it's a very simple disconnect.

 

[desert runner]

This is an ideal time for a tazer reboot if you have one. This is one reason I like the 2.0 you disconnect the battery and it’s dead. The 3.6 you have another one to deal with.

I had tried that, but I believe the instrument cluster must be on the music screen to engage tazer. The electronics were stuck on the error message and I could not navigate to the music screen.

 

[Rploaded]

I had tried that, but I believe the instrument cluster must be on the music screen to engage tazer. The electronics were stuck on the error message and I could not navigate to the music screen.

Ah yes so you needed a full battery pull. Sorry to hear that happened. These new vehicles are so sensitive to anything out of spec including low voltage.

 

[Rploaded]

There's just two studs on the right inner fender you disconnect to kill the whole system (edit: in addition to main batt neg). I "arrowed" mine w an Inkzall to help w my CRS when welding on the rig.

A minor inconvenience for sure, but far from insurmountable

I totally forgot about the ground posts! That’s a fast way also. Thank you for reminding me of those.

 

[Kyanche]

On mine I pulled the ground post on the left and the ground terminal on the main battery. When I did that the interior had no power but I still got sparks if I touched a ground connected to the terminal against the chassis. What finally did it for me was disconnecting the 2 parts of the negative terminal from each other. One had a black box with a red cable attached to it. My guess is that was connected to the aux battery.

 

[aprez27]

Indeed we disconnected the main battery in an attempt to reset. However, the second battery must have kept the system alive, so the reset did not work that way. We did not disconnect the second battery.

Happened to me a week ago after driving 70 miles. The only way I got that humming to stop was disconnecting the main ground which is right next to the battery, attached to the side of the jeep.

Another tip, if using one of those portable starters, disconnect the negative terminal and connect the starter to the wires you just disconnected, that will then just try to charge the battery that starts the Jeep and not the main battery. I was able to get mine jumped that way, but my fuses were shorted out already so I was stuck. Jeep said it was shutting down shortly.

 

[desert runner]

Happened to me a week ago after driving 70 miles. The only way I got that humming to stop was disconnecting the main ground which is right next to the battery, attached to the side of the jeep.

Another tip, if using one of those portable starters, disconnect the negative terminal and connect the starter to the wires you just disconnected, that will then just try to charge the battery that starts the Jeep and not the main battery. I was able to get mine jumped that way, but my fuses were shorted out already so I was stuck. Jeep said it was shutting down shortly.

Thanks Andrew, good info to have. Indeed the remote start battery may be overwhelmed having to recharge two batteries and jump the car at the same time. Taking the main battery out of the equation then makes sense.

Interesting that you also heard (a solenoid?) humming. Can you tell me a bit more about the situation you were in, e.g.

• What made your fuses short out?
• Where any error messages displayed on the instrument cluster?
• Where you in 4L when you jumped the engine? I am wondering whether being parked in 4L contributed to my electronics being "confused"

Thanks, Peter

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