ESS Dual Battery Management

[Rhinebeck01]

After having the TSB 18-092-19 pcm update applied a few weeks ago and then after subsequent trial and error testing on my part.....

I strongly urge those with 2018, 3.6 JL/JLU's to go out of your way to get this TSB applied to your vehicle, ASAP

IF, you do not have the update applied, I predict, you will in the near future, really regret not doing so. (Unless you are using a bypass jumper)

Note: If your JL, has over 36,000 miles on it and your basic warranty has expired, do know that this update is still covered under your longer, Power Train Warranty.

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[Jebiruph]

After having the TSB 18-092-19 pcm update applied a few weeks ago and then after subsequent trial and error testing on my part.....

I strongly urge those with 2018, 3.6 JL/JLU's to go out of your way to get this TSB applied to your vehicle, ASAP

IF, you do not have the update applied, I predict, you will in the near future, really regret not doing so. (Unless you are using a bypass jumper)

Note: If your JL, has over 36,000 miles on it and your basic warranty has expired, do know that this update is still covered under your longer, Power Train Warranty.

This update fixes more than the bad aux - no start issue on the 2018s, so if you haven't yet, get it done already.

It will not affect the amount of boost needed to jump start dead batteries, you're still jump starting 2 batteries.

 

[Rhinebeck01]

Attached is a copy of TSB 18-092-19 . It is urgent that you get this TSB applied to your 2018 JL/JLU. Bring a copy of this TSB with you to the Service Department.

DO, be sure to unmarry and remove your Tazer JL, if you have one on your vehicle, before you go to the Service Dept.

When you go to the Service Department, you MUST complain about the issues listed on the TSB.

Important: IF you mention you want the TSB applied, to change the way your 2018 JL/JLU deals with starting, the dealer will undoubtedly not want to do the update...

Service Writer needs to actually hear you lets say, say the magic words, listed on the TSB, so he can type it into his computer and have FCA give TSB recommendation/ok to apply.
With that said just lie to dealer with a straight face.... but reality is you undoubtedly have a 2018 JL that exhibits the first two things on the list, because most if not all 2018's do.

The 2018 JL/JLU, owner's I know just mentioned the excessive blower fan noise and the intermittent rough idle and that was all that was needed to be complained about, to get the TSB applied to their 2018 vehicle.

IMPORTANT: For any reason, iF, the dealer will not apply the TSB update to your JL, (Talk to Service Manager) do not argue, but just walk outside and call the Dedicated Jeep Customer Care: Ph. 1-866-362-2146 and ask that they intervene. They will call the dealer and work things out so your JL, gets the update.

Customers may experience one or more of the following:
• Excessive blower fan noise when the A/C is on MAX output.
• Intermittent rough idle or idle surging, when coming to a stop (Automatic transmission
equipped vehicles only).
• Random Electronic Stability Control (ESC) lamp illuminates in the Instrument Panel Cluster
(IPC).
• Driving at vehicle speeds while in first gear and shifting into neutral, a message 9Shift to 1st
gear not allowed9 message appears in the Electronic Vehicle Information Center (EVIC) when
conditions are not met (Manual transmission equipped vehicles only).
• 3 km (2 mph) difference between cruise set speed versus actual display speed.
• During cold vehicle operation and the use of cruise control on vehicles equipped with an
automatic transmission, the engine RPMs may drop below idle speed while cruise control
is engaged, this may occur if the customer presses the accelerator pedal to achieve a vehicle
speed greater than the cruise control speed and then releasing it.

 

[OldGuyNewJeep]

Excessive blower fan noise when the A/C is on MAX output.

I can confirm that these are the magic words.

 

[Htfan]

Attached is a copy of TSB 18-092-19 . It is urgent that you get this TSB applied to your 2018 JL/JLU. Bring a copy of this TSB with you to the Service Department.

DO, be sure to unmarry and remove your Tazer JL, if you have one on your vehicle, before you go to the Service Dept.

When you go to the Service Department, you MUST complain about the issues listed on the TSB.

Important: IF you mention you want the TSB applied, to change the way your 2018 JL/JLU deals with starting, the dealer will undoubtedly not want to do the update...

Service Writer needs to actually hear you lets say, say the magic words, listed on the TSB, so he can type it into his computer and have FCA give TSB recommendation/ok to apply.
With that said just lie to dealer with a straight face.... but reality is you undoubtedly have a 2018 JL that exhibits the first two things on the list, because most if not all 2018's do.

The 2018 JL/JLU, owner's I know just mentioned the excessive blower fan noise and the intermittent rough idle and that was all that was needed to be complained about, to get the TSB applied to their 2018 vehicle.

IMPORTANT: For any reason, iF, the dealer will not apply the TSB update to your JL, (Talk to Service Manager) do not argue, but just walk outside and call the Dedicated Jeep Customer Care: Ph. 1-866-362-2146 and ask that they intervene. They will call the dealer and work things out so your JL, gets the update.

Customers may experience one or more of the following:
• Excessive blower fan noise when the A/C is on MAX output.
• Intermittent rough idle or idle surging, when coming to a stop (Automatic transmission
equipped vehicles only).
• Random Electronic Stability Control (ESC) lamp illuminates in the Instrument Panel Cluster
(IPC).
• Driving at vehicle speeds while in first gear and shifting into neutral, a message 9Shift to 1st
gear not allowed9 message appears in the Electronic Vehicle Information Center (EVIC) when
conditions are not met (Manual transmission equipped vehicles only).
• 3 km (2 mph) difference between cruise set speed versus actual display speed.
• During cold vehicle operation and the use of cruise control on vehicles equipped with an
automatic transmission, the engine RPMs may drop below idle speed while cruise control
is engaged, this may occur if the customer presses the accelerator pedal to achieve a vehicle
speed greater than the cruise control speed and then releasing it.

This!

Great wisdom in Rhinebeck01's post. Also, this strategy is true for all TSBs in my experience. The dealership will not apply TSBs without a specific problem reported as listed in the associated TSB bulletin.

In this particular case for TSB 18-092-19, the updated Aux battery logic is not listed for some reason.

 

[FiveBoro]

My 2018 will start on the second attempt with the aux neg cable disconnected. Far as I know the TSB was never performed, at least it's not on any of the paperwork I have from the dealer. Strange

 

[Gee-pah]

My 2018 will start on the second attempt with the aux neg cable disconnected. Far as I know the TSB was never performed, at least it's not on any of the paperwork I have from the dealer. Strange

Same here. Just called the dealer today. They say I never got TSB 18-092-19 and yet my 2018 will start with no aux battery connected after an initial failed attempt to crank, turning on the ESS off light on the dash until the next cold crank when a working ESS/Aux battery (or at least that at the end of the factory cables which normally lead to the ESS/Aux battery is connected to an energized source) is connected.

Maybe FCA switched over the logic on this during part of the 2018 model year production run. Maybe this change was also part of another TSB as well.

 

[Rhinebeck01]

My 2018 will start on the second attempt with the aux neg cable disconnected. Far as I know the TSB was never performed, at least it's not on any of the paperwork I have from the dealer. Strange

@FiveBoro

A 2018 JL/JLU without TSB 18-092-19 applied, will absolutely, not behave this way.. so... guess what.. 8-)

I guess, sure.... there is a possibility that a 2018 at the very very tail end of the production year run, could have had the same power train programing as the 2019 production models.

 

[Kurt0]

I've always thought it would be good to be able to isolate the aux battery and keep it as a reserve battery, especially when overlanding. Here's what I've come up with to implement that, and for managing the batteries in general. It uses a battery switch connected to the aux battery ground cable, a bypass jumper and a voltage gauge for each battery.

It's still somewhat of a prototype, I have figure out some way to mount the volt gauges.

To hook it up, you remove the aux battery ground cable from the main battery ground terminal and connect it to the battery switch stud and connect the battery switch cable back to the main battery ground terminal.
The red cables connect to N1 and the main battery positive terminal. You should remove the fuse when connecting the red cables to avoid accidentally shorting them out. Here's a diagram.

Here's running with the batteries separated, the volt meters show the main battery charging and the aux battery not.

Battery charger charging just the main battery.

Battery charging just the aux battery. EDIT- You should be able to leave the positive cable on the main battery and just move the negative cable to the aux battery.

Here's with the main battery disconnected after a successful test of starting with just the aux battery. EDIT- It's not necessary to unplug the battery sensor.

very similar to the set up ive run overseas in modded out trucks running tons of electric and comm gear and it works very well. I think youre on the right track.

 

[Jebiruph]

This!

Great wisdom in Rhinebeck01's post. Also, this strategy is true for all TSBs in my experience. The dealership will not apply TSBs without a specific problem reported as listed in the associated TSB bulletin.

In this particular case for TSB 18-092-19, the updated Aux battery logic is not listed for some reason.

It's not listed, but I checked mine after it was updated and found the Aux battery logic changed. That's how we know.

 

[Htfan]

It's not listed, but I checked mine after it was updated and found the Aux battery logic changed. That's how we know.

You are correct. However, it's important to let people know that the dealership only cares about what's documented in the TSB when they are servicing the vehicle.

 

[Jebiruph]

You are correct. However, it's important to let people know that the dealership only cares about what's documented in the TSB when they are servicing the vehicle.

Got it. For me, my base 5" radio always reset, loosing it's place and playing the same song almost every time I got in. There was an update for the radio that required the PCM update that required the ABS update. Some one posted that there's an update to fix the slow clock on the radio. When that's available, the should also trigger the PCM update for those that don't have it yet.

 

[MacJack]

This was a great post... you always impress me. So my question I do not have any of the symptoms as listed below... I got my JLR 3.6 on Oct 2018 and on Nov 6, 2018 had to replace Pvc Switch.

So how do I know if I have this flash or not. Can I find it or can my dealer look? For the record my Jeep running good, only issue is finding the speakers with negative polarity so I'm replacing with new speakers and correct in the polarity.

Thanks again.

Customers may experience one or more of the following:
• Excessive blower fan noise when the A/C is on MAX output.
• Intermittent rough idle or idle surging, when coming to a stop (Automatic transmission
equipped vehicles only).
• Random Electronic Stability Control (ESC) lamp illuminates in the Instrument Panel Cluster
(IPC).
• Driving at vehicle speeds while in first gear and shifting into neutral, a message 9Shift to 1st
gear not allowed9 message appears in the Electronic Vehicle Information Center (EVIC) when
conditions are not met (Manual transmission equipped vehicles only).
• 3 km (2 mph) difference between cruise set speed versus actual display speed.
• During cold vehicle operation and the use of cruise control on vehicles equipped with an
automatic transmission, the engine RPMs may drop below idle speed while cruise control
is engaged, this may occur if the customer presses the accelerator pedal to achieve a vehicle
speed greater than the cruise control speed and then releasing it.

Edit: read more of the post so if I remove the neg AUX battery cable will tell me if I have the flash?

 

[Gee-pah]

So how do I know if I have this flash or not.

I'd think a dealer could tell you that if you provide them with your VIN.

Edit: read more of the post so if I remove the neg AUX battery cable will tell me if I have the flash?

I'm not sure. More important is why.

I did test my 2018 just as you describe. The first crank attempt, no surprise, failed because the check of the ESS/Aux battery for current prior to engine crank found no voltage given the temporary cable removal you describe--which by the way is the cable on the main battery's negative terminal CLOSER to the front passenger's quarter panel.

A second attempt at the crank switched the rig over to the main battery and started it up, disabling ESS with a diagnostic light.

This new behavior remaining until after turning the vehicle off after a couple of cranks, and reattaching the cable, the default cranking behavior returned and the ESS diagnostic warning light turned off.

My call to the dealer yesterday asking if I had PCM update TSB 18-092-19, which I thought I did, was responded to with a "no."

@FiveBoro recently reported the same thing.

Perhaps some 2018's got the behavior of switching to the main battery that 2019's and beyond got. Maybe this fix is part of other TSBs. Maybe I did get the TSB and the dealer told me no incorrectly.

 

[MacJack]

So I did the remove the AUX Battery negative cable test and dash flashed and started right up. So thanks to you all for the peace of mind in this Post.

Food for thought for those JL 2018 production Jeeps:
So if I got my Jeep in Oct 2018, I think it took 2 weeks to ship, so Jeep sat in the lot awaiting for a truck to come down, leaves my Jeep may have been in production at QC in Sept 2018. So who knows if they fixed it then. I did run my vin for TSB 18-092-19 and did not show I needed it.

Who knows and thank again for you all sharing.

Jack

I'd think a dealer could tell you that if you provide them with your VIN.

I'm not sure. More important is why.

I did test my 2018 just as you describe. The first crank attempt, no surprise, failed because the check of the ESS/Aux battery for current prior to engine crank found no voltage given the temporary cable removal you describe--which by the way is the cable on the main battery's negative terminal CLOSER to the front passenger's quarter panel.

A second attempt at the crank switched the rig over to the main battery and started it up, disabling ESS with a diagnostic light.

This new behavior remaining until after turning the vehicle off after a couple of cranks, and reattaching the cable, the default cranking behavior returned and the ESS diagnostic warning light turned off.

My call to the dealer yesterday asking if I had PCM update TSB 18-092-19, which I thought I did, was responded to with a "no."

@FiveBoro recently reported the same thing.

Perhaps some 2018's got the behavior of switching to the main battery that 2019's and beyond got. Maybe this fix is part of other TSBs. Maybe I did get the TSB and the dealer told me no incorrectly.

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