EV mode not switching on or off

Could be that SOC simply is too low. At the lower end of 4-bar range, it can be as low as 49%. SOC <50% is "EV deny" range.

 

Could be. In another recent thread, at least a couple of us (Diamondlarry and I, in particular) reported "EV deny" events in some of our colder days this winter (sub-20F), with a cold battery as one possible cause. In that thread, Ken@Japan reports that 32F is the low limit of battery temp for EV operation.

One somewhat common -- and curious -- theme is that EV has been denied only when we haven't been able to run the block heater, whereas those who always use the EBH haven't reported a problem. I can't see how the block heater would have any effect on battery temperature, given their physical separation. But the symptoms are undeniable.

Larry and I had some dialog about this in CleanMPG a few weeks ago. At the time I told him I would start watching all my temperatures via CAN-View (battery, engine block, coolant, MG1 & MG2, and both inverters) as it was happening. Unfortunately for this purpose (though fortunately for the sake of fuel economy), it hasn't been cold enough to trigger a recurrence since then.

For the sake of this thread, I should mention that this "EV deny" is not the same as the "misfires" I previously reported here. There were no EV deny signals during the misfires, whereas the issue reported in the other thread includes outright EV deny indicators: the 3 short beeps and "EV deny" displayed on CAN-View.

 

Once again resurrecting this ....

After a long period of the original behavior recurring only sporadically, it recently has been happening daily, usually multiple times per day. It's finally gotten frustrating enough to replace the switch. Plan A was to replace it with the same switch. But when I got to Radio Shack to pick it up, I got to wondering whether a more rugged switch was available that would fit in the existing hole.

So I ended up with this one and installed it last night. I didn't necessarily want the red button. I figured it might attract a little more undue attention from a technician if the car was in the shop, resulting in a notation in their files that I had the switch and potentially creating warranty issues later if I ever had a battery problem like Naterprius. But it didn't come in black. And I like the "beefier" feel to the button. I think it will be easier to feel and push in the winter with thick gloves on.

This morning, no misfires at all, so preliminarily, at least, it appears the problem has been resolved. Thanks to all here, especially Daniel for first casting suspicion on the switch and a key bounce.

 

Yes, I've seen the same thing, and it's frustrating. The problem with goosing the pedal is that if you goose it too much you stand a chance of forcing it into "WOT" (wide-open throttle) mode where, quite curiously, it often remains even after partially backing off the go-pedal. Hobbit has described it (with his own terminology variant ):

[SIZE=+1]"If we push RPM well up over 3000, something completely different happens that
I've referred to as "WFO mode", a common play on "WOT" or wide open throttle.
Under serious high-power demand, it's pretty clear that the engine goes into
either an open-loop or enrichment-driven mode to deliver that. Evidence of
this is LOUD intake noise, larger throttle openings, vacuum at *zero*, and
scooting briskly down the road with MPG completely in the toilet. What's more
interesting is that if demand is brought down very slowly, it can *stay* in
that mode while returning down to 2000 RPM or below, with vacuum still at
zero and injector timing hunting all over the place but remaining fairly
long. This is a completely useless state for high mileage, but one should
be aware of its existence simply because if the WFO mode is entered, the
way out of it is to back completely off the accelerator and gently reapply."[/SIZE]
​

I have the benefit of CAN-View telling me when I'm in WOT mode. There seems to be a small range of pedal position where "EV deny" can be forced without also forcing WOT, one that's hard to hit with a relatively imprecise "pedal-goose."

 

Calibrate our gooses, huh? I don't know you well enough.

(Imagine what a newbie would think jumping right to these posts without knowing the background.)

It may be that the pedal position window I mention actually is wider than I thought. In the few times I've tried jabbing () the pedal to force EV deny, it seemed I often hit WOT despite my best efforts. I'll admit I'm not well practiced at it and it probably hasn't been well-controlled. After I got "WOT" on CAN-View two or three times, I quit trying. And I too could display throttle position on CV but exploring the window width is not of particular interest to me, assuming the new switch continues working.

Meanwhile, here's a pic of the new switch installed:



I think I can get used to the red button. I could have some fun when friends ask, "What's that?"