Unnatural EV Mode Access

[Rokeby]

I've been playing around with my EV mode switch from Coastaletech
since last Thanksgiving. I have to agree with the many who say that
the best use for it is to suppress ICE-On before the engine, catalytic
converter, and maybe the HV battery get warmed up. I also have a
ScanGauge so I can see where the various bits are in their warm-up.

Anyone who has played around with an EV mode at lower ambient air
temps is familiar with the three beeps and MFD screen message that
announce a denial of access to the EV mode. When this happens, in
my experience there is no recourse but to continue on your way,
cursing under your breath until the necessary EV mode preconditions
are met, particularly getting the ICE up to 110 degF so it will shut
down when the vehicle stopped.

Well, maybe not!

On four separate occasions I have been able to take advantage of
some quirk in the HSD that has allowed me to access EV mode to
supress ICE ops with the ICE coolant temp as low as 75 degF. Here's
how it went:
* Outside temps were about 40 deg. This is significant because
around 32 deg, after an overnight cold-soak, there is an HV battery
low temp EV mode prohibition.
* For whatever reason EV mode had been denied.
* Coolant temps variously between 75 and 84 degF
* While at a stop with the ICE running, I felt a slight shudder or
stutter from the ICE.
* Figuring this might mean some kind of phase change or algorithm
shift, I tried to engage EV mode...
* And it worked! ICE shut down was really rough, but shut down it
did, and I could move off in EV mode.
* Also, before coolant temps reached 110 deg, I could slip in and out
of EV mode at will.

Has anybody else seen this HSD behavior before?

Could it be harmful to the ICE, HV battery, control CPU(s), etc?

[JimboK]

It just sounds like you've reached S2, which arrives pretty consistently within 60-70 seconds after a cold startup regardless of ICE temp. I've often seen onset of S2 with ICE temps below 80F in winter.

[TonyPSchaefer]

I believe that some time ago Ken (Yoshi) indicated that you can force an EV mode exactly 55 seconds after start-up.

[Rokeby]

Tony,

thanks for that bit of information, I was not aware of that.

I can't say what the time was after start-up. It very well could have been
at 55 seconds. The key event was the small ICE shudder while stopped.
I guess the shudder/shiver is attentuated or masked when you're moving

I'll have to carry a stopwatch and see if I can confirm coincidence of the
55 sec thing and the ICE shudder.

[Boo]

Maybe your cell phone has a stop watch among its tools?

[Rokeby]

Boo,

Good idea. The problem is, I'm an anachronism.
I don't have a cell phone...

However, my analog wrist watch does have a sweep second hand. If I
wear my reading glasses, I can even see it if I turn the cabin overhead
light on.

I'll give it the old college try.