Theories on ESS

[Rahneld]

Here's what I think I know. If wrong set me straight. : - )

When cold cranking the 3.6L JL the starter relay is, if only for an instant, solely dependent upon the ESS battery to communicate to the starter.

Otherwise, at all other times, the ESS and main batteries are connected in parallel, free, along with the alternator when the JL is on, to charge each other/get charged (assuming the ESS battery can accept a charge and isn't broken.)

Why do you think FCA designed the small battery of a non-essential system (ESS) the critical task of powering the starter relay?

Even if the ESS battery fails while the vehicle is running, the ESS system won't engage, to need the vehicle's starter relay to signal the starter to restart the stopped JL in the first place--right?

I'm very confused. I don't even know if my prior paragraph is factual. To this point, are separate starters or mechanisms involved in cold cranking, versus ESS cranking the vehicle?

Thank you.

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[Rahneld]

@JeepCares

 

[Uhdinator]

I think the E torque motor does the ESS restart, and cold start is a conventional starter for the 2.0L. Which seems likely as the 2.0L is much smoother, seamless, and very quiet when restarting compared to the 3.6L ESS system.

 

[mwilk012]

I think the E torque motor does the ESS restart, and cold start is a conventional starter for the 2.0L. Which seems likely as the 2.0L is much smoother, seamless, and very quiet when restarting compared to the 3.6L ESS system.

ESS and "E-torque" do not exist on the same vehicles.

 

[Jebiruph]

Here's what I think I know. If wrong set me straight. : - )

When cold cranking the 3.6L JL the starter relay is, if only for an instant, solely dependent upon the ESS battery to communicate to the starter.

Otherwise, at all other times, the ESS and main batteries are connected in parallel, free, along with the alternator when the JL is on, to charge each other/get charged (assuming the ESS battery can accept a charge and isn't broken.)

Why do you think FCA designed the small battery of a non-essential system (ESS) the critical task of powering the starter relay?

Even if the ESS battery fails while the vehicle is running, the ESS system won't engage, to need the vehicle's starter relay to signal the starter to restart the stopped JL in the first place--right?

I'm very confused. I don't even know if my prior paragraph is factual. To this point, are separate starters or mechanisms involved in cold cranking, versus ESS cranking the vehicle?

Thank you.

When the PCR has the batteries connected in parallel, the Main battery voltage and the ESS battery voltage both connect to everything, including the starter relay. Are you thinking that all cold starts are the same as ESS starts?

 

[Rahneld]

When the PCR has the batteries connected in parallel, the Main battery voltage and the ESS battery voltage both connect to everything, including the starter relay. Are you thinking that all cold starts are the same as ESS starts?

Let me put my questions this way.

The PCR (I think that's your PCM: Power Control Module) doesn't have the batteries connected in parallel at the moment of cold crank, true--they're isolated?

I think I know that this is a brief instant and at all other times the batteries are connected in parallel, vehicle on or off--is this true and what you're saying above? And if so, a ESS battery that won't accept a charge, even if hooked up to the main battery and/or the alternator is part of a vehicle that if on, once turned off won't cold crank again.

(I define cold crank here as pushing the start button with the brake pedal pressed.)

This is why I thought the 3.6 won't start if the ESS battery is disconnected/dead, because in this brief moment in time the starter relay relies solely on the ESS battery.

Now the batteries are also disconnected in a stop start event--I know.

I think in a cold crank, it would have been nice if the vehicle, upon detecting an ESS battery problem, sourced the start relay's power needs to the main battery, just like your N1<->N2 jumper does.

I think this is a non-issue for ESS events because the event doesn't occur in the first place, to leave the driver stuck with a starter relay that won't work because the ESS battery is dead, because the ESS battery is tested, and if not powered, ESS won't engage in the first place.

Thank you for your time and knowledge. : - )

It's to me almost as if the engineers said, "we don't have to worry that the starter relay depends on the ESS battery because an ESS event won't occur in the first place if the ESS battery is dead....."

completely forgetting about the exception that occurs in cold cranks.

I bet I have this all wrong!!

~~~~~~~~

 

[Jebiruph]

Let me put my questions this way.

The PCR (I think that's your PCM: Power Control Module) doesn't have the batteries connected in parallel at the moment of cold crank, true--they're isolated?

I think I know that this is a brief instant and at all other times the batteries are connected in parallel, vehicle on or off--is this true and what you're saying above? And if so, a ESS battery that won't accept a charge, even if hooked up to the main battery and/or the alternator is part of a vehicle that if on, once turned off won't cold crank again.

(I define cold crank here as pushing the start button with the brake pedal pressed.)

This is why I thought the 3.6 won't start if the ESS battery is disconnected/dead, because in this brief moment in time the starter relay relies solely on the ESS battery.

Now the batteries are also disconnected in a stop start event--I know.

I think in a cold crank, it would have been nice if the vehicle, upon detecting an ESS battery problem, sourced the start relay's power needs to the main battery, just like your N1<->N2 jumper does.

I think this is a non-issue for ESS events because the event doesn't occur in the first place, to leave the driver stuck with a starter relay that won't work because the ESS battery is dead, because the ESS battery is tested, and if not powered, ESS won't engage in the first place.

Thank you for your time and knowledge. : - )

It's to me almost as if the engineers said, "we don't have to worry that the starter relay depends on the ESS battery because an ESS event won't occur in the first place if the ESS battery is dead....."

completely forgetting about the exception that occurs in cold cranks.

I bet I have this all wrong!!

~~~~~~~~

If the ESS system is disabled until the engine warms up, do you think they would use it to start a cold engine?

 

[allieboy]

If the ESS system is disabled until the engine warms up, do you think they would use it to start a cold engine?

ESS system vs ESS battery? Even if ESS system wont be activated til engine warm...wont ESS BATTERY still be called to assist at startup?

 

[allieboy]

Im soooooo confused! Lol

 

[Rahneld]

If the ESS system is disabled until the engine warms up, do you think they would use it to start a cold engine?

Here is my answer that you sir, as you helped me understand much of--and I thank you.

Yes, I most respectfully not only think the ESS battery will still be called, not merely to assist, but exclusively, need be, effect startup--even if the ESS system won't be activate until, among other conditions, the engine is warm.

I absolutely could be wrong. But right or wrong, here's where I draw my findings. I do NOT wish to come off as disrespectful, especially to someone who has likely forgotten more on this subject than I know.

Point 1) The ESS battery can, to my understanding, cold start the vehicle even when the main battery is disconnected.

Point 2) As both the main and ESS batteries appear to be 99.99% of the time connected in parallel (i.e. except for the start event)--100% of the time for you given your ingenious N1<->N2 jumper ideas, either battery effectively charges the other and by that fact, plays a role in assisting the startup sequence, even if those batteries are briefly isolated during it.

Please....sir...I urge you, so I understand, so we all understand, educate me where I have misspoken--and it's entirely possible I have.

Peace.

 

[Rahneld]

ESS system vs ESS battery? Even if ESS system wont be activated til engine warm...wont ESS BATTERY still be called to assist at startup?

Here's what I think I know--and it isn't much or even possibly wrong.

If I am wrong, please, somebody say so.

First, let's define "assist."

It's my understanding that the ESS battery is isolated from the main battery upon 3.6L startup, be it a cold or ESS system startup, and solely provides power to the starter relay, to tell the starter to do its task of cranking the engine, even this is only for an instant in time.

Once the relay sends its message to the starter, but before the starter begins its task, both batteries are reconnected in parallel. I believe this because I believe a 3.6L can be started on a working ESS battery alone.

I believe that the starter relay gets its power only from the ESS battery upon the instant of startup when the batteries are seperated because no ESS battery or a dead one, barring Mr. @Jebiruph's N1<->N2 jumper, will prevent the engine from cold cranking.

I believe this a non-issue for ESS (as opposed to cold cranking a.k.a. pressing the start button with your foot on the brake) cranking because you'll never enter an ESS event if the vehicle first detects problems with the ESS battery. No opportunity for an ESS event to disable recranking the rig is apt to occur in the first place because of this check of the ESS battery before, in addition to other conditions (e.g. ESS off, engine cold), an ESS event occurs.

~~~~

Now for another definition of "assist." 99.999% of the time, (100% if you have Mr @Jebiruph's jumper connected full time,) the batteries are connected in parallel and charge each other, in addition to the alternator charging them both when the vehicle is on.

In this regard each battery essentially assists the either to handle the very start event that for an instant isolates them.

 

[Jebiruph]

ESS system vs ESS battery? Even if ESS system wont be activated til engine warm...wont ESS BATTERY still be called to assist at startup?

Since the ESS battery is connected in parallel at the time, it will provide power during regular starts. The ESS system is what isolates the batteries during an auto stop.

 

[allieboy]

Since the ESS battery is connected in parallel at the time, it will provide power during regular starts. The ESS system is what isolates the batteries during an auto stop.

I guess I was thinking of ESS battery being dead. Without jumper and aux battery ground removed...it wont be fun.

 

[allieboy]

I guess I was thinking of ESS battery being dead. Without jumper and aux battery ground removed...it wont be fun.

Pardon me for a moment while i stick my knife in an outlet!

 

[Rahneld]

Pardon me for a moment while i stick my knife in an outlet!

I think if you just keep Mr @Jebiruph 's neat hack at your disposal, and know to try it (and remember how to do it) if your ESS battery is dead and your JL won't crank, that you don't need to worry about the mechanics of why this is so.

: - )

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