I know its been asked and it might be a "duh" obvious question but...how do you know when EV mode kicks in?

Living in a hilly region I figured we simply don't have any flat even roads where I could go solo electric at slow speeds.

However sometimes while gliding down backroads I notice the mpg indicator suddenly drops and goes to one blip. This all while im still gliding and just gently depresing the gas. Any change in foot pressure makes the mpg bar jumps back up. This also happens at higher speeds while cruising at times on the highway, say 50-55 mph. I don't hear any obvious difference in noise, not that I hear the engine noise unless climbing.

Is the odd drop in the mpg display the EV mode? or is there a more obvious signal it is active? I guess we all can learn things even if we thought we knew all there was to know about our car

 

You can tell when the valves are closed on the engine, when the mpg indicator goes to 100 and the IMA battery starts to charge. If you tap down lightly, you can make it charge less, then no charge (just coasting), then it will start assisting. When this is happening (the mpg is at 100 and the asst indicator is showing 1 or more bars), you know that you are using only the electric motor.

I don't know what the drop in the mpg display would be, unless you are putting extreme pressure on the pedal. It sounds like when doing what your doing the mpg indicator shouldn't drop, but raise to 100. Have you experienced what I'm describing? If so, that is EV mode.

Also, have you gotten the PCM update?

 

I've had this happen quite a few times at different speeds and it's kinda weird when it does happen because you think you've pressed on the gas pedal. I haven't figured out exactly how or when it happens, but I do know it is functioning in EV mode when it does happen because my mpg will continue to increase. It does happen when I have a light, steady pressure on the pedal while in EV-Glide and/or having 1 or 2 assist bars. However I do remember reading about this briefly and found the paragraph I was looking for:

From Tarabell's "Adapting Basic Hypermiling Techniques to the HCH-II" on cleanmpg.com


Green&Blue first reported this unique mode/feature in the thread entitled HCH-II on electric only and I hoped to try and fit it into this article if I could reproduce it. Luckily I have, so if Mark does not mind, I will summarize his description here. Basically what happens is that while in a “Glide”, between 30 - 42 mph and the iFCD maxed, the iFCD will unexpectedly drop to nearly zero and then does a jerky crawl back up towards 100 mpg again and stays there. I have only seen this happen when my engine is starting from cold, and I'm heading down a slight hill. When this happens I do not see the aFCD increase as I would expect from going downhill, but can't be sure if that's due to the cold startup or some effect of the recal. Mark however reports he can maintain this longer than “EV-Assist” mode and at higher speeds too! I can attest that it’s unusual to see the instantaneous suddenly drop for no apparent reason. The typical driver reaction is to wonder WTH happened and immediately lighten your right foot to make it go back to the right. If you’re patient and maintain the exact same foot pressure, the iFCD will climb back up all by itself (with a samba rhythm) and remain pretty steady up there. It appears to be some sort of recalibration although iFCD’s should not be affected by this phenomena knowing what we know today?


Hope this helps "somewhat". If anyone has any more information on this "unusual phenomenon" please post it here.

 

Oops... also guess it would be good to answer the original question as well...

You know you're truly in EV mode when your iFE meter is pegged at 100mpg and if you press lightly on the accelrator, the iFE stays pegged at 100mpg and you will see white assist lights (up to 4). If you see the iFE drop at all, then you're not in EV mode.

 

The recalibration debate has gone on in other posts. If my car is recalibrating when it does that, I've got the most "calibrated" car on the planet! I think it's more likely a software bug (someone suggested a divide by zero error), but since it really doesn't do any damage, they haven't done anything to fix it.

I hardly even notice it anymore, but I have seen it samba at all speeds with warm and cold engines. It does seem to be more prevalent in the cold though. The hardest thing is to resist the urge to let your foot off the gas when it happens!

 

As an update to my own thread, while having the dealership fix a minor issue with interior parts coming loose, I requested if they knew about a PCM update. They told me there was an update relating to errors in mpg dispay resulting from a potential faultly tachometer.

This might be what I noticed, not sure as the car is there overnight now awaiting a parts order.

 

Folks,

I am not sure if the "EV mode" exists on the HCH II or if it matters. The HCH has a ICE with a motor/gen as a flywheel along the crankshaft. The ICE still has to turn at all times (friction) and the electric motor assist is not all that strong. This is very different than the Toyota system or next generation systems from GM/Chrysler.

The best it is designed to do is shut down valves and fuel when coasting and let the IMA motor generate electricity.

What's fun about the HCH design is that it gets close to the Prius mileage with a fairly simple system that costs less to make.

Doberwiler

 

So any update on this? Does your car still do the Samba?

 

No samba anymore. mpg display doesn't have odd drops at least from what I've seen this week. Looks like it was all just an internal glitch.

I'm kinda dissapointed thou...I thought I was getting into EVmode during these little mpg drops, I wonder if I'll ever see that mystical driving mode short of visiting Lynch Toyota.