Jumperless Aux Battery Bypass

[PegFundy]

Correct. Just make sure the disconnected aux cable is taped up real good so it can't short to anything. By pulling the fuse, you prevented seeing the error message. You can operate like that indefinitely.

This is amazing. Thank you!

Sponsored

 

[Snowman315]

I recently acquired a 2022 JL high tide with v6 gas engine. I had heard about the battery issues from others that I know that have lived through those issues. After reading this thread and others, and you tube videos I went out to the garage today to pull the fuse and disconnect the ground cable. When I opened the hood, I realized I have the 48v lithium battery etorque system. Does all this info about pulling the fuse and negative cable still apply? What little info I could find about etorque leave me with rhe impression that the fuse pull and ground disconnect dies not apply to etorque models. Is that correct?

 

[Jebiruph]

I recently acquired a 2022 JL high tide with v6 gas engine. I had heard about the battery issues from others that I know that have lived through those issues. After reading this thread and others, and you tube videos I went out to the garage today to pull the fuse and disconnect the ground cable. When I opened the hood, I realized I have the 48v lithium battery etorque system. Does all this info about pulling the fuse and negative cable still apply? What little info I could find about etorque leave me with rhe impression that the fuse pull and ground disconnect dies not apply to etorque models. Is that correct?

Correct, doesn't apply.

 

[dpike]

Fuse pulled, ground disconnected.
?

 

[MTGOAT]

so.... I pulled the fuse and the aux negative cable as described a few weeks ago and I am still getting no starts. I put the battery on a trickle charger for about a week just to be safe. No start happened again this morning. Started up fine. Drove 18 miles to drop my kid off at school. Turned it off for about 5 mins while I walked her to the door. Came back and it wouldn't do anything. Lights are good. Battery reads 12.5v. wouldn't even try to turn over.

Had to use a lug nut to jump the two posts to get her started. Once running battery read 14.5v

for reference, TSB 18-092-19 is supposed to address this issue however I am 90% sure I got the update and it still has issues starting.

 

[ken31756]

Great post and love this forum! Special thanks to those who have contributed much helpful information, especially @Rhinebeck01 and @Jebiruph

I noticed a post earlier by @Pixels_JLU asking about the engine light remaining on after removing 42 and negative cable to AUX. No one seemed to tackle that question.

I have the same problem now myself. 2018 JLU Sahara late model year build, replaced the main battery just today, pulled the 42 fuse, and disconnected the neg cable to the Aux battery. Everything seems fine so far (awaiting for the learning curve to kick in) but the engine light is remaining on. Will this go off in time on its own, or do I need to reset something?

@Jebiruph Amazing amount of info in here and I thank
You and everyone else. Seems Aux batt killed main yesterday so had to get new one. Removed negative to Aux, installed new batt, removed 42. Started right up. Taser kept ESS button in off. But I have engine light on dash now. Is this common? Does it clear? No Obie to this part so please thanks for all info,

JP

 

[T-Rob]

Great post and love this forum! Special thanks to those who have contributed much helpful information, especially @Rhinebeck01 and @Jebiruph

I noticed a post earlier by @Pixels_JLU asking about the engine light remaining on after removing 42 and negative cable to AUX. No one seemed to tackle that question.

I have the same problem now myself. 2018 JLU Sahara late model year build, replaced the main battery just today, pulled the 42 fuse, and disconnected the neg cable to the Aux battery. Everything seems fine so far (awaiting for the learning curve to kick in) but the engine light is remaining on. Will this go off in time on its own, or do I need to reset something?

Ken,
Do you have to have a Tazer? If so, just clear it. If not, I “think” you just need to find a way to clear it. Once you clear it, I believe it will not come back.

Tim

 

[ken31756]

Thanks Tim, I have a FlashCal which is similar to Tazor and allows me to read and clear diagnostic codes. I'm going to give the jeep a few trips curious to see if it self corrects and if not I use the Flashcal.

 

[ken31756]

UPDATE:
Checking with my FlashCal the diagnostic code reader shows an error code U0010 CAN Interior BUS.
Has anyone had this code come up after changing the main battery, pulling the 42 fuse and disconnecting the aux battery ground?
I'm not sure exactly what the error code is suggesting? A short in the wiring, or is it just because the aux battery is not "visable"?

 

[Jimac]

UPDATE:
Checking with my FlashCal the diagnostic code reader shows an error code U0010 CAN Interior BUS.
Has anyone had this code come up after changing the main battery, pulling the 42 fuse and disconnecting the aux battery ground?
I'm not sure exactly what the error code is suggesting? A short in the wiring, or is it just because the aux battery is not "visable"?

This happened to mine this fall. Had both batteries changed out (4 1/2 years old). Turned out to be bus N-3 blown. Moved wires to N-4 (spare bus bar) and everything was ok. Don’t know if this is your situation but this fixed mine.

 

[ken31756]

I can give that a try. My N-4 is available.

Is there a way to test the N-3 (i mean without ripping everything out) or is it easier to just move the cable over one and see what happens?

 

[Jebiruph]

UPDATE:
Checking with my FlashCal the diagnostic code reader shows an error code U0010 CAN Interior BUS.
Has anyone had this code come up after changing the main battery, pulling the 42 fuse and disconnecting the aux battery ground?
I'm not sure exactly what the error code is suggesting? A short in the wiring, or is it just because the aux battery is not "visable"?

For some the a! error light turns off automatically. I have always disconnected both batteries for a few minutes to clear it. Regarding the U0010 error code, this is the first time I've seen someone post a code associated to a! error light. I suspect it's the result of the aux battery failing it's test. As for a blown N3 fuse, there is no error code, just an eventual failed start.

 

[Down South]

I’ve been following the threads concerning bypassing the Aux battery and taking the Aux battery out of the loop “Delete”.

I’m interested in deleting the Aux battery and I’ve read the numerous results. Most of the results are positive.

I understand disconnecting the Aux battery cable from the main battery then insulating and securing the loose cable end.

I understand the need to pull fuse F42.

I can understand replacing the main battery with a size H7 for the extra CCA.

What I have yet to understand is why does the ESS need to be bypassed every time the Jeep is started?
I don’t see amp draw as a problem with an activated ESS using only a main battery as some have stated. That doesn’t make sense. Did I miss something in the hours of reading I've done?

 

[Rhinebeck01]

I’ve been following the threads concerning bypassing the Aux battery and taking the Aux battery out of the loop “Delete”.

I’m interested in deleting the Aux battery and I’ve read the numerous results. Most of the results are positive.

I understand disconnecting the Aux battery cable from the main battery then insulating and securing the loose cable end.

I understand the need to pull fuse F42.

I can understand replacing the main battery with a size H7 for the extra CCA.

What I have yet to understand is why does the ESS need to be bypassed every time the Jeep is started?
I don’t see amp draw as a problem with an activated ESS using only a main battery as some have stated. That doesn’t make sense. Did I miss something in the hours of reading I've done?

@Down South

I have been running with the Aux bypassed on my 2018 JL with 3.6, since 2019.

I have accumulated approx. 65,000 miles, running with just the Main.

YES, on occasion, over all those years/miles, I have used ESS. No problems doing so at all. Yes, I do purposely limit use of ESS... but again, I do use it occasionally.

Suggest you disregard the one forum member's recent, repeated posts that make it sound like your JL will have major issues if you dare to occasionally use ESS if your Aux battery is bypassed.

 

[Down South]

@Down South

I have been running with the Aux bypassed on my 2018 JL with 3.6, since 2019.

I have accumulated approx. 65,000 miles, running with just the Main.

YES, on occasion, over all those years/miles, I have used ESS. No problems doing so at all. Yes, I do purposely limit use of ESS... but again, I do use it occasionally.

Suggest you disregard the one forum member's recent, repeated posts that make it sound like your JL will have major issues if you dare to occasionally use ESS if your Aux battery is bypassed.

Thank you for confirming my thinking.

Sponsored