Are the batteries really isolated during ESS stops?

[J Sierra]

Top trace N1 and N2 lower trace is terminal near F42. Not sure what it is.

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[ShadowsPapa]

Top trace N1 and N2 lower trace is terminal near F42. Not sure what it is.

F42 is the fuse for the relay that controls the PCR, or the big power control relay near the aux battery.

 

[J Sierra]

I know what the fuse is, not sure what the terminal near it is. The lower trace is the terminal in question.

 

[J Sierra]

I was going to probe F42 then I found the terminal next to F42

 

[jebiruph]

I was going to probe F42 then I found the terminal next to F42

It looks like the terminal you found follows the expected behavior of the PCR, so good find. Is this the terminal?

And thanks for the oscilloscope image, the third channel further verifies the cold start behavior. Did you happen to get a 3 channel image of the ESS restart?

 

[J Sierra]

That is the terminal. The relay that runs the PCR is on the PCB. I think that is what it is. I was going to get channel 4 on starter relay. Will get the ESS restart today.

 

[Andy29847]

This is how I am reading the test that J Serria made. This is a cold start.

 

[ShadowsPapa]

This is how I am reading the test that J Serria made. This is a cold start.

Yes, my thought exactly.
And that terminal is a test terminal according to what I see.

The PCR opening is before the crank event, which is how the documents describe the PCM test of batteries it uses to determine if the batteries will support an ESS stop.

Since the PCM is connected to N1, the voltage it sees directly will be what the aux battery state of charge is and the IBS will report the voltage of the crank battery, so it can tell if it's able to support ESS starts.

 

[jebiruph]

Yes, my thought exactly.
And that terminal is a test terminal according to what I see.

The PCR opening is before the crank event, which is how the documents describe the PCM test of batteries it uses to determine if the batteries will support an ESS stop.

Since the PCM is connected to N1, the voltage it sees directly will be what the aux battery state of charge is and the IBS will report the voltage of the crank battery, so it can tell if it's able to support ESS starts.

From my reading of information you provided in an earlier post, it's not reading any voltages during the cold start testing, it's just determining if the aux battery has enough power so the PCM doesn't reset when the PCR opens.

And these "Set Conditions:" are probably one of the more consequential bits of information in this thread as they indicate that the PCM is assessing the Aux battery's performance under load during an ESS event and will set the P00FD if a faulty Aux battery is detected.

So maybe when some one thinks they have a bad Aux battery, running a few ESS events would be a way of load testing it.

 

[ShadowsPapa]

From my reading of information you provided in an earlier post, it's not reading any voltages during the cold start testing, it's just determining if the aux battery has enough power so the PCM doesn't reset when the PCR opens.

Well, it sort of is - a threshold voltage - during the disconnect the voltage is only that of the aux battery.

It has to read the voltage to make this determination -

It also has to know about the main/crank battery voltage as that's used in multiple determinations, including "can it crank again" and the IBS when all things are connected, is reporting a voltage that's not of the main alone.

The system is told what size batteries are installed, you'll find info about the battery capacity in JSCAN logs.

 

[jebiruph]

Well, it sort of is - a threshold voltage - during the disconnect the voltage is only that of the aux battery.

It has to read the voltage to make this determination -

It also has to know about the main/crank battery voltage as that's used in multiple determinations, including "can it crank again" and the IBS when all things are connected, is reporting a voltage that's not of the main alone.

The system is told what size batteries are installed, you'll find info about the battery capacity in JSCAN logs.

I was specifically referring to the cold "initial key" start as specified in these details, when the batteries are separated prior to starter engagement. It gives an approximate voltage, but it states it's testing for a PCM reset. If the PCM resets, the Aux battery fails the test.

This information seems to apply to the ESS restart when the batteries are separated during initial starter engagement. That's when the voltage of the Aux battery is evaluated.

 

[J Sierra]

The terminal near F42 measures 36 ohms to GND. I found two terminals near starter relay. You can see one in the picture that Jerry posted. Top center of picture.

 

[J Sierra]

Same as before with bottom trace, looks like starter relay GND.

 

[jebiruph]

Same as before with bottom trace, looks like starter relay GND.

Looks good, another cold start image?. Tektronix TDS2014B 100MHz 1GS/s Four Channel Digital Storage Oscilloscope? Looks like it runs on AC, are you going to be able to drive with it hooked up to get an ESS event restart?

 

[ShadowsPapa]

Looks good, another cold start image?. Tektronix TDS2014B 100MHz 1GS/s Four Channel Digital Storage Oscilloscope? Looks like it runs on AC, are you going to be able to drive with it hooked up to get an ESS event restart?

Maybe if the inverter keeps going during a restart...........depending on the version of JT he has.

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