Trouble Codes you never want to see

it is a diode. it's used as an amplifier.

the problem is due to a weak signal in the cell voltage monitoring circuit. it will read 0 volts in all cells no matter what the actual charge. all this does is boost the signal with the actual voltage so the system knows what the actual voltage is.

 

I stopped in a local dealership's parts desk today and asked to see
the widget in question, part number 82163-47180. The guy looked
and said they don't stock it, and he even checked if their particular
dealership had *ever* ordered one. Answer: no. So they've never
done EG023-04 at this dealership, evidently. If I wanted to pay
$34 or whatever I could have ordered one to dissect, but my VIN is
past the threshold so I don't actually need it. Maybe next time
I'm in the battery box I'll look for it, but it wouldn't surprise
me if in later cars it's done as an internal improvement in the
ECU itself.
.
I'm at a loss to understand how a diode is used as an "amplifier",
by the way... remember, whatever the device is gets connected
ACROSS the 12V power and ground leads to the ECU. That's usually
the job of a decoupling cap, although I could believe a reverse
diode to prevent the power rail from going negative during power-off
conditions, pushed there by random HV battery voltages from the
sense leads and the fact that the HV battery floats independent of
the car's ground. A transient coming out of that state at the next
power-up could conceivably confuse the ECU for a while, unless the
+12 is held close to ground level in the meantime.
.
There's gotta be a real engineered answer to this.
.
_H*