behavior of "EV button" gauge in Hymotion Prius

I think I asked this question before, but it was part of a longer email and might not have been noticed:

I have a Hymotion system installed in my Prius.

I do not have a separate EV-mode switch installed.

I have an "EV-button" gauge programmed into my ScanGauge. Normally, it displays the word, "ON," or the word, "OFF," which tells me whether my Hymotion system has put me into EV mode or not.

The EV-button (evb) gauge actually seems to have FOUR modes:
1) steady ON
2) steady OFF
3) flashing back and forth between ON and OFF, but spending most of its time ON
4) flashing back and forth between ON and OFF, but spending most of its time OFF

Has anyone else experienced this? I haven't been able to figure out what these "flashing back and forth" modes represent or what triggers them. Any ideas?

Thanks.

Arthur

 

No, my "evb" gauge is not always flashing. It only flashes (between ON and OFF) under certain circumstances. If I am in "cold EV mode" (been in EV mode since the car was started), it never flashes. It only flashes if I am in "warm EV mode" (gotten back into EV mode after the ICE has been running) AND a certain sequence of events has occurred. I'm not sure what that sequence of events is, exactly. Often, even after the engine has been running, I get back into the mode where the evb button is NOT flashing. In this case, the car seems to behave the same as if it is in cold EV mode. Maybe it is.

There definitely seems to be a difference between the "mostly ON" mode (with quick flashes of "OFF") and the "mostly OFF" mode (with quick flashes on "ON." I'm not exactly sure what the difference is, yet. I suspect that one of them is some form of EV mode and the other is not EV mode at all.

Do you have trouble changing settings on your climate-control screen? Does it jump back to the energy screen before you can press the buttons on the climate screen? I only have this problem when I am in one of the "flashing back and forth" EV modes. I never get the screen jump when I am in the "steady ON" EV mode.

This EV mode behavior may seem less "normal" to me because I spent a lot of my time driving in "steady ON"/"cold EV mode."

 

Yeah, that makes sense.

The thing that confuses me is that the spoofing is going on whenever the Hymotion system is turned on and has battery power. However, the "EV-button" gauge only flashes (between ON and OFF) SOME of the time.

The thing that makes it worse is this: Sometimes, this happens when the car is warmed up enough that it SHOULD be in "normal" EV mode ...but isn't.

I started this thread because I'm getting really confused between all these different "versions" of EV mode.

It seems that when it is "mostly ON," but flashing briefly to OFF, EV mode is not really active. ...and in many of these cases, it SHOULD be active!

What gives!?

 

I think I've figured out what the problem was. It seems like my ScanGauge is interfering with my ability to get into EV mode.

I've been using an active SOC (state of charge) gauge. When I turn that gauge off, I don't seem to have the problem. I'm trying a passive SOC gauge, but it doesn't seem to give the same information.

I'm planning to get a CAN-view system soon. Hopefully, that will allow me to get all the same info (and more) and avoid this kind of problem.

You're obviously right that it has something to do with the spoofed CAN packets. The switching between "ON" and "OFF" (of the "EV button" gauge) happens at about the same rate as the spoofing flashes of the Prius energy display (between Hymotion SOC and Prius SOC).

Fortunately, there appears to be a way to avoid the whole problem, though (just not use the active SOC gauge, or at least turn it off before the car tries to get into EV mode).

Arthur

 

Yeah, I spoke too soon. It was wishful thinking. I wanted to believe that I had figured it out. Then, it did it again today, even without the SOC gauge.

 

Yes, and the same thing happens when I use the active SOC gauge. That's one of the reasons why I've switched to the passive SOC gauge.

As I said, I spoke too soon about eliminating my problem of my "EV button" (EVB) gauge switching repeatedly between ON and OFF (and not really ever being in EV mode). Although that problem still occurs (even WITHOUT the active SOC gauge), I have noticed that I do eventually get into EV mode. With the active SOC gauge, it seemed that I could never get from the switching mode to the real EV mode, no matter how long I drove.

I'll have to try both with and without the active SOC gauge (over a period of several days) and find out for sure whether the SOC gauge is a contributing factor to the problem in any way.

Arthur

 

Below is a message I wrote to Hymotion. (At this point, they're suggesting that having ANYTHING connected to the OBDII port could potentially cause a problem. So, I'm going to try disconnecting my ScanGauge completely and see if I still get the "EV flashing on and off.")

--------------

I was talking to another Hymotion owner who told me that the spoofing information that is sent to the Prius (to trick the traction battery into accepting more charge and to cause the energy display to alternate between Hymotion SOC and Prius SOC) includes the EV mode status. That would explain why the EV mode status (as seen on my "EV button" gauge) alternates the way it does.

This still doesn't give me an absolute answer about whether the ScanGauge is playing a role in this problem, but it does explain some things.

Below is a reply I wrote. Please read it and see if it sheds some light on any of this. Pay particularly close attention to the part at the end about EV mode kicking on while I'm going up hill. It causes a lot of jerking as the engine shuts off while running at a pretty high RPM. I'm a little concerned about this.

As I said, I'll completely disconnect the ScanGauge and see if that eliminates the problem.

Thanks again for helping me work through this stuff. (Please read the other message I have pasted in below.)

Arthur

-----------------------------------------

Hmmm... That's interesting. The behavior of my "EV button" gauge is starting to make sense now. It flashes ON and then (less than a second later) it flashes briefly to OFF and then back to ON again. That's the same as the energy screen flashing briefly to the Prius SOC and back to the Hymotion SOC. So, the OFF status must correspond to the actual Prius EV mode status. That makes sense, since the car obviously isn't in EV mode when this is happening.
The question is: "What does it mean for the Hymotion system to be in an EV mode ON status when the Prius is really in an EV mode OFF status?" Does it mean that the Hymotion system is "deluded" and thinks that the car is in EV mode? That would explain why it's difficult to get into EV mode after that point. (If the Hymotion system thinks that the car is already in EV mode, it probably stops sending requests for EV mode.)
The question still remains: Why does it sometimes go into EV mode normally and at other times go into this confused mode?
I've noticed some other weird behavior: When I'm in this "mostly ON" mode (flashing briefly to OFF) and I give it a little too much "gas" pedal, it switches to a "mostly OFF" mode (EVB gauge displays "OFF", with brief flashes to "ON"). (Presumably, this means that the Hymotion system thinks that EV mode has gone off, but it seems to also mean that EV mode is actually ON, in a situation where it would normally have just gone OFF.
I'm sure this sounds very confusing, but it may start to explain another weird behavior of the Hymotion system: When I am in this "switching ON and OFF" mode and am going up a steep hill, the engine keeps shutting off. When I give it a lot of gas pedal, it goes into EV mode and the engine switches off. (It doesn't stay in EV mode for more than a couple seconds.) Even if I back off of the gas pedal, instead of staying in EV mode, it exits EV mode and the engine comes back on.

 

OK. I believe you. The ScanGauge is not the problem.

I'm just trying to follow up on what I've been told by someone at Hymotion: "Any time you plug anything into the OBDII port you can potentially alter the messaging on the CAN bus."

If you tell them that your CAN-View sees the same thing (even without a ScanGauge connected), perhaps the people at Hymotion will respond by saying that the CAN-View is also plugged into the OBDII port and could be CAUSING the same problem. How would you respond to that?

It is definitely possible to demonstrate that the problem still exists, even with NOTHING connected to the OBDII port. The car behaves in certain unique ways when it is in this mode (the mode that causes a ScanGauge or a CAN-View to display EV mode flashing between "ON" and "OFF").

Did you see what I wrote in my previous message about driving up a steep hill while EV mode is flashing between ON and OFF? The car keeps going into EV mode for a second or so. Then, EV mode shuts off. Several seconds later, it goes into EV mode again, but it never stays in EV mode, even if you back off of the accelerator.

This behavior is definitely observable WITHOUT a ScanGauge and this behavior is definitely connected with the "EV mode flashing between ON and OFF" problem. There is no way that it would ever happen unless you are in that "flashing" mode.

So, I'm going to disconnect my ScanGauge and leave it disconnected for several days. Hopefully, that will resolve the question of whether this problem has anything to do with CAN bus interference throught the OBDII port.

Arthur

 

It's actually the opposite. Heavy acceleration (including going up a hill) causes it to go INTO EV mode, but only for a couple seconds. When this happens, I've tried to back off of the accelerator, but, despite that, it always goes back OUT of EV mode.

This weird behavior only occurs when the EV-button gauge on my ScanGauge is alternating between ON and OFF. It alternates at about the same frequency as the energy display alternates between Hymotion SOC and Prius SOC.

My hypothesis is that the alternating ON and OFF really means that the Hymotion system thinks that the car is in EV mode and the Prius system knows that it's really not.

When EV mode kicks in on the hill, the EV-button gauge reverses its behavior. It displays "OFF" for a good fraction of a second (presumably meaning that the Hymotion system thinks EV mode is off) and then flashes to "ON" for a tiny fraction of a second (corresponding to the fact that the Prius system really IS in EV mode at that point).

Then, when it kicks back out of EV mode, the EV-button gauge goes back to displaying mostly ON, with quick flashes to OFF.

I don't know what triggers it to go into this weird mode. It seems like the Hymotion system gets out of sync with the Prius's EV mode status. Then, it stays out of sync, causing weird things to happen.

This is not something new. My car has always done this, even before they updated my firmware. It seems like a flaw in the Hymotion software. Until now, I've just sort of shrugged it off as "something I didn't understand."

But, as I've started to understand what the flashing between ON and OFF means, I'm starting to realize that this is definitely abnormal (unintended) behavior.

Arthur

 

I unplugged my ScanGauge before starting my car today. On the way home, I went up my big hill. At first, I was going 9 mph and the engine was off. When I am in EV mode, I can go all the way up the hill this way and the engine never kicks on (as long as I keep a steady foot on the accelerator and don't go above 9 mph).

Today, the engine kicked on after several seconds of going 9 mph. Then (while keeping a relatively light foot on the accelerator and keeping my speed under 30 mph), the engine kept kicking off and then back on again. About every 7 seconds, the engine would kick off for just long enough that my instantaneous mpg display would show 99.9 mph for a fraction of a second. Then, after being in EV mode for only a second or so, the engine would kick back on again (even though I did NOT increase my acceleration -- if anything, I decreased it).

So, the ScanGauge doesn't seem to be the problem, but I'm going to keep the ScanGauge unplugged until I get a better explanation for this. That way, nobody can tell me that it is causing the problem.

Arthur

 

Both.

I thought you said in an earlier message that the "flashing" of EV mode was normal behavior and that you see it all the time.

I usually start my car in EV mode and drive it such a way that it stays in EV mode. If I do that, this problem NEVER occurs. (That's one of the reasons that I've let this go so long without trying to figure it out.) It only happens when the ICE has been running and then shuts off. At that point, if the Hymotion system makes a request for EV mode, it will either go into EV mode or it will go into this "flashing" version of EV mode. When the latter happens, the car is not in EV mode at all.

Have you noticed that your car is not really in EV mode when your EV mode indicator is flashing between ON and OFF (but spending most of its time displaying ON and only briefly flashing to OFF)? When it is doing the opposite (spending most of its time displaying OFF but only briefly flashing to ON), you actually ARE in EV mode.

Is this what you experience? If not, how does yours behave?

Thanks.

Arthur

 

I still have my ScanGauge disconnected.

Today, I did about 10 miles on the highway at 65 mph. So, the car was definitely warmed up. Then, I drove about halfway up my hill in EV mode (~10-15 mph). (I was obviously in EV mode because the engine would have started if I wasn't.) Then, I pressed the accelerator a little harder and the engine kicked on.

As I was driving normally up the second half of the hill, I noticed that the engine kept shutting off (every several seconds).

This behavior seems to occur at really random times. It doesn't seem to matter whether the ScanGauge is attached. It doesn't seem to matter whether the car is warmed up. It doesn't seem to matter whether I'm going uphill or on flat ground.

The only thing I know for sure is this:

After driving for a while in regular mode (not EV mode), a situation occurs where the Hymotion system requests EV mode. At that point, one of two things happens. Either the car will go into EV mode normally, or it will go into this other mode where the Hymotion system seems to think that the car is in EV mode, but it really isn't. If it goes into EV mode normally, it always stays in EV mode until I do something to cause it to exit EV mode.

If it goes into the other (non-EV) mode, that's when this weird behavior (repeatedly switching INTO EV mode for only a second while accelerating or going up a hill) occurs.

I have no idea what causes it to do one thing and not the other. It seems totally random, but there has to be some explanation.

I don't understand why nobody else has experienced this. Other people have ScanGauges (or CAN-views) and pay as close attention to what their car is doing as I do.

Is this just my car? I have a 2008 model. Is this something that only happens with certain model years of Prius? Is that why so few people have seen it?

Hymotion has not been very helpful. They don't seem to have seen this behavior before, either, and don't have any ideas (except to blame it on the ScanGauge, which I've eliminated as a possible cause).

"The Force" seems to have seen the confused EV mode status behavior (EV status flashing between ON and OFF at about the same rate that the energy screen flashes between Hymotion SOC and Prius SOC --- and that's why I think that the Hymotion system has gotten out of sync with the Prius system and thinks that it is in EV mode when the Prius system knows that it actually is not). However, "The Force" doesn't use the Hymotion system to control EV mode. He does it manually with a separate EV mode switch. So, he's never going to see the weird EV mode behavior that I see when this "out of sync" situation occurs.

Is there anyone else out there who has experience anything similar to this? Please speak up, because I need your help.

Thanks.

Arthur