Start stop battery dead again??

[kapk22]

NO...
https://www.jlwranglerforums.com/forum/threads/deleting-removing-the-aux-battery.166850/

much better. thank you

Sponsored

 

[Jebiruph]

This is really confusing. Is he saying the negative terminal going to the auxiliary is “cable B”?

If this is correct, pulling that off the main and wrapping electrical tape around it should do the trick, correct?

Then I will just replace the main battery and eventually pull that old auxiliary battery out of there. I assume leaving the positive terminal on that auxiliary battery won’t hurt anything, since it doesn’t have a ground to close the circuit. I will snap a picture of my terminals!for reference as well.

Your cable B is thicker than your cable A, so you have the newer cables and your cable A connects to the aux battery.

 

[AndySpill]

Dang... I didn't want to tackle removing that stupid battery until the weekend.

Once you disconnect the Aux battery from the vehicle's electrical system you never ever have to removed the Aux battery, for the life of the vehicle, let alone should you feel a sense of time urgency to do so if in fact you want to.

If I have the Tazer mini, do I still need to pull the fuse?

Thaw addressed that in the affirmative even if with his somewhat critic tendency to assume everyone here's a mechanic.

To point, the Tazer mini can be configured to turn engine start stop off and I recommend you do so.

What it won't do is prevent the vehicle from trying to access, in isolation, the Aux battery at engine cold crank times as is part of the the vehicle's normal cold crank procedure.

(The other time that the vehicle seeks to isolate the Aux battery is during start stop events, (which you'll prevent with your tazer) from happening.)

This Aux battery isolation as the only connected battery is effected by energizing the Power Control Relay (PCR): which when it receives power disconnects the main battery. Pulling Fuse 42 prevents the PCR from ever receiving power.

 

[kapk22]

Once you disconnect the Aux battery from the vehicle's electrical system you never ever have to removed the Aux battery, for the life of the vehicle, let alone should you feel a sense of time urgency to do so if in fact you want to.



Thaw addressed that in the affirmative even if with his somewhat critic tendency to assume everyone here's a mechanic.

To point, the Tazer mini can be configured to turn engine start stop off and I recommend you do so.

What it won't do is prevent the vehicle from trying to access, in isolation, the Aux battery at engine cold crank times as is part of the the vehicle's normal cold crank procedure.

(The other time that the vehicle seeks to isolate the Aux battery is during start stop events, (which you'll prevent with your tazer) from happening.)

This Aux battery isolation as the only connected battery is effected by energizing the Power Control Relay (PCR): which when it receives power disconnects the main battery. Pulling Fuse 42 prevents the PCR from ever receiving power.

I watched a couple of videos on YouTube where the guys removed the auxiliary battery, taped up the ground (that was connected to the aux) and left it inside the empty aux battery housing. Then they pulled the positive up and connected it to the main battery. Both guys showed their dash and no error messages/lights were on. One of the guys said he had tried pulling fuse 42 and still had problems. He did however, say it may have to do with different models.

I am just about to head outside now and tackle this. Unfortunately I don’t have a garage or shade and it’s pretty damn hot out there on the concrete driveway. Wife suggested setting up our little patio pop up awning.

Thanks for the help. Hopefully I can get this done fairly quickly.

 

[THAW]

To point, the Tazer mini can be configured to turn engine start stop off and I recommend you do so.

Tazer configuration is not required; the sole requirement for preserving ESS button state is simply that the Tazer be installed (so it can execute the "Non-Menu" Live Function).

 

[THAW]

I watched a couple of videos on YouTube where the guys removed the auxiliary battery, taped up the ground (that was connected to the aux) and left it inside the empty aux battery housing. Then they pulled the positive up and connected it to the main battery. Both guys showed their dash and no error messages/lights were on. One of the guys said he had tried pulling fuse 42 and still had problems. He did however, say it may have to do with different models.

Connecting the AUX (ESS) battery positive cable terminal connector to the CR[an]K (main) battery positive post obviates fuse F42 removal. That is, one step or the other is necessary to avoid a dash light, but both together also work.

 

[kapk22]

Connecting the AUX (ESS) battery positive cable terminal connector to the CR[an]K (main) battery positive post obviates fuse F42 removal. That is, one step or the other is necessary to avoid a dash light, but both together also work.

they said they "just fished the positive back up"

Uhhhh, that was a nightmare. I finally got it through and getting it back together. Had to stop for some AC and water a couple times. Gotta get it together for work tomorrow.

 

[AndySpill]

Tazer configuration is not required; the sole requirement for preserving ESS button state is simply that the Tazer be installed (so it can execute the "Live Function").

This is correct, it not also Thaw's propensity towards anality.

Perhaps the Tazer being "married," as opposed to configured is a more accurate description; "configuration" being something more apropos for attributes like gear ratios where values are set.

The mere installation/marriage of the Tazer JL or Tazer JL mini will find it memorializing the state of the ESS button on the dash and reintroducing that state between cold cranks.

This behavior is different than that where no Tazer has been introduced, where ESS is always on upon old crank, as required by the EPA (e.g. a non-latching ESS button, defaulting to ESS on, that DOESN'T remember its state between cold cranks) requirement for manufacturers to able to report more favorable MPG numbers on their vehicle's Malroney stickers.

 

[AndySpill]

I watched a couple of videos on YouTube where the guys removed the auxiliary battery, taped up the ground (that was connected to the aux) and left it inside the empty aux battery housing. Then they pulled the positive up and connected it to the main battery

Provided Fuse 42 is removed, this action kindly stated is superfluous and more like silly/unnecessary work.

Kasey, imagine a kid's toy running on two AA batteries when one is battery is bad. Imagine those batteries connected in parallel, positive to positive, negative to negative.

I ask you to disconnect that bad battery and you in response pull the wire/cable connecting the negative posts. Do you need to do more? No.

Both guys showed their dash and no error messages/lights were on. One of the guys said he had tried pulling fuse 42 and still had problems.

Let me take this in reverse order. The guy who continued to have issues after pulling Fuse 42 (in concert with disconnected the Aux battery) had issues unrelated, IMHO, to the Aux battery being taken out of the vehicle's electronics. His problems could have not been battery related, or, facing a dying main battery, indeed battery related; but not because of the Aux battery and Fuse 42 pull. In fact a dead Aux battery may very well cannibalize the main battery while its connected to it.

Kasey, lets do a slightly deeper dive here. With some understanding of what's going on I think you'll completely appreciate what needs removal, what doesn't, and why.

In dual AGM battery JLs, upon cold crank, forum member testing has shown that the Aux battery is examined in isolation for an instant to determine its state of charge. This is accomplished by the vehicle energizing the Power Control Relay for an instant, which takes the main battery out of the vehicle's electronics during this time so that the Aux battery can be tested in isolation. Stated differently, placing a tester on the terminals of either the main or Aux battery, as long as the batteries are connected (in parallel), can lead to incorrect conclusions about that battery's charge, as it can be supplemented or partially depleted by the other battery (connected to it) being strong or weaker respectfully.

Pulling Fuse 42 prevents the PCR from being energized, that fuse pull itself generating no error messages within the vehicle; the vehicle being unaware. So when calls to isolate the Aux battery are made by the vehicle, the main battery remains connected and it is alone, provided the Aux battery has been disconnected, that which is tested, and the vehicle thinks it has tested the Aux battery.

There are other methods for preventing the main battery from ever being temporarily disconnected during this test. One such method involves taking the cables that use to connect to the Aux battery and placing them on connection points back to the main battery. Another involves jumpering places https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/ in the fuse box (a.k.a. PDC); the de facto method before @Jebiruph discovered the Fuse 42 method.

None of these approaches are mutually exclusive; you could do more than one, much as you'd be wasting your time if you did, the Fuse pull being the cleanest.

So what, (the final point here,) might happen if you disconnected the Aux battery and did nothing else? Well, in early model 2018s you wouldn't be able to start. But for those that were flashed with TSB 18-092-19 and all newer dual AGM JL models, normally, your first attempt at cranking will fail in these cases, but subsequent ones will succeed and the vehicle will illuminate the ESS off light in the dash, and from that point forward the vehicle will crank on the first attempt.

On the surface this sounds cool: a positive side effect of the vehicle turning ESS off when you don't want it to engage anyway sans the Aux battery connected.

But people who know more on the board than me believe that this light turning on can be an early warning sign for troubles that would be masked if the light were already on.

I hope that clears up what's necessary, what isn't, what's superflous, and why.

 

[Red Rubi 22]

Bypass it. The thinner cable goes to the aux battery.

 

[kapk22]

Bypass it. The thinner cable goes to the aux battery.

All done. No error messages or lights.

 

[THAW]

Perhaps the Tazer being "married," as opposed to configured is a more accurate description; "configuration" being something more apropos for attributes like gear ratios where values are set.

No, Tazer doesn't have to be married for "Non-Menu" Live Functions, just installed (i.e. plugged in).

 

[WillysMeow]

I did as Bryce919er and wrap both ESS battery cables and put them back in the box. When my warranty is up, I'll unwrap the harness and fish out those two extra wires and run jumper from N1 to N3.

 

[Opus]

I got the Stop/Start disabled notification so I decided to do the Auxiliary Battery bypass. At that point my main battery was showing consistently in the 13 volt range. After the bypass we went on a road trip and since we've been back the voltage has been 14.1 or 14.2. I'm guessing the Aux battery had been draining the main but with the bypass the main has been able to recharge fully and maintain its proper voltage.

In November it will be 4 years on the OEM batteries.

Sponsored