Blue EV bar missing when car is in EV mode

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dpuhrmann

dpuhrmann

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Have seen some strange behavior 2 different times after having my software upgraded by the dealer in mid-December. Here is what I see:
  1. Car starts with or unexpectedly starts ICE even though there is a full battery and I am not in HV mode nor pushing the pedal hard.
  2. Eventually I see the "EV" text popup under "READY" but the blue bar doesn't show up on the power circle (not sure what the technical term is for this), it is still the dashed white circle as if I was driving in HV mode. See attached picture.
  3. While driving, I can see the "EV" text come and go randomly (doesn't seem related to how hard I am pushing the pedal/what the car is doing) and when it is on, it sounds like the car is in EV mode and it is draining the battery.
  4. I haven't had this problem resolve itself, I need to stop, turn the car off and then back on to get it back to "normal".
Anyone else seen this/know what the issue is?

Thanks,
Dave
 

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Based on the picture, it looks like you are in "Normal" mode which means that ECON and SPORT are both off. If you want the car to behave like EV most of the time then you will need to select ECON mode, which will heavily favor using the battery over the engine. It doesn't mean that the engine will never come on. There are four cases where it will trigger the engine to start in ECON mode:
  • Pressing the accelerator pedal past the 75% level (where you will feel the click)
  • When unused for long periods of time, some people have witnessed the engine coming on unexpectedly for 5 minutes or so and then turning off for another long hibernation. It is believed this is normal behavior to keep the engine running smoothly by circulating oil, etc.
  • Running regenerative braking when the EV battery is full or close to full - since the battery cannot accept any more charge when it is full it appears to start the engine to make use of engine braking to use up the kinetic energy. I suspect this was the cause in your case #1. People who encounter this most often are those who live on high terrain, and charge up the battery full overnight and then proceed to go downhill with the battery full or close to full.
  • Obviously, if the battery is used up, the car will revert to using the engine and what is left of the EV battery as in HV mode.
I believe the EV will come and go more regularly when in Normal mode. Also the engine trigger from the accelerator pedal drops down to ~50% (from 75% in ECON mode), but I think this is variable depending on whether the engine is warm, and the state of charge of the battery. I don't have much experience with Normal mode, so it is hard to prescribe exactly the conditions where the EV will overrule the engine. Suffice it to say the the engine will tend to spark to life more often in Normal mode.
 
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Agreed and understood all your points above and this is how the car normally functions. But in every case (other than these 2) when it switched into EV mode, there is a blue bar on the power circle that indicates you are using battery and the right end of the bar indicates where the ICE needs to be engaged if you push the pedal past that point.

In this case, even though the car is in EV and using EV, the power bar doesn't show blue anywhere, it appears as if it is only using ICE. I included the part about the ICE being on as I have only ever seen the missing blue bar issue when the car started running with the ICE. Understood that could happen for many different reasons, but assuming when the car switches to EV, it should show blue on at least some portion the power circle.
 
I've had the same thing happen to me a few times when I push hard on the accelerator pedal. I have found that if I keep driving, it eventually resolves itself. I decided not to worry about it since it seems to only be some grey on the dash vs. blue.
 
That's exactly happened to mine today too (#1 & #3) after owned this car for ~3 months. Honda must did something via HondaLink but won't tell us.
-capt3450
 
This sometimes happens to my Clarity, too, even when in ECON mode. The white line is dashed in my case. The car is in EV mode as the ICE is not running (The ECON and EV icons are on). I fix it my switching to sport mode and back to EV or HV mode and back to EV mode. I do not need to shut the system down and restart.

This started to happened after the October software update. I think there is just a problem in the new software with respect to the driver display. I also think that this is related to the fact the the gear icon in direct drive mode does not always come on when the ICE seemed to be in direct drive mode. The dash display software may misread various sensors.

LeoP
 
Based on some discussion here, it is my understanding that the ICE will run through an ~10 minute cycle each time it is started, no matter how long it is actually used for HV mode. Apparently, this allows the engine to heat up, oil to run through everything, and burn off any moisture in the system. You can circumvent this by turning the car off and back on again, but for long-term ICE health, it sounds like it is preferable to let it complete the cycle if you're going to be in the car long enough for it to do so. Intentionally turning off the car to save a tiny bit of gas sounds like a penny-wise, pound-foolish plan to me.
 
Let me be very clear. When our Clarity gets into this odd display mode of having a totally white curved line (dashed in our case), the powertrain is in EV mode and the ICE is not running. If the ICE is running, switching back and forth between modes will not turn the ICE off. Only the ICE reaching and staying at the operating temperature for a while or shutting the car off will have the effect of stopping the ICE. I am not advocating that the ICE be shut off prematurely at any time but rather just a way to reset the driver's display to the correct output. As I said before, I think the problem is just the driver's display not displaying the correct information from the sensors, perhaps losing a data packet or something similar that says that the mode has changed (rather than having a sensor signal that gives the state of the system).

BTW, I usual drive our Clarity with an OBDII dongle attached and the data for various sensors logged on a tablet. So, I know when the ICE is running and the engine coolant temperature (ECT).

LeoP
 
leop said:
Let me be very clear. When our Clarity gets into this odd display mode of having a totally white curved line (dashed in our case), the powertrain is in EV mode and the ICE is not running. If the ICE is running, switching back and forth between modes will not turn the ICE off. Only the ICE reaching and staying at the operating temperature for a while or shutting the car off will have the effect of stopping the ICE. I am not advocating that the ICE be shut off prematurely at any time but rather just a way to reset the driver's display to the correct output. As I said before, I think the problem is just the driver's display not displaying the correct information from the sensors, perhaps losing a data packet or something similar that says that the mode has changed (rather than having a sensor signal that gives the state of the system).

BTW, I usual drive our Clarity with an OBDII dongle attached and the data for various sensors logged on a tablet. So, I know when the ICE is running and the engine coolant temperature (ECT).

LeoP
Click to expand...
Sounds like a warranty repair is needed for this. Doesn’t sound like operator error.
Have you tried rebooting the head unit (even though it’s erroring on the DII) and forcing a whole system reboot by disconnecting the 12v battery for a few minutes? It’s a shot in the dark, but who knows.
Hope you can get this frustrating problem fixed. Keep us posted.
 
Sounds like you're braking on a slightly hilly area once you fully charge the battery. To prevent overcharging of the battery the engineers have decided to program the ICE to sometimes turn on to engine brake.
 
kevosuki said:
Sounds like you're braking on a slightly hilly area once you fully charge the battery. To prevent overcharging of the battery the engineers have decided to program the ICE to sometimes turn on to engine brake.
Click to expand...

Because the engine can be connected mechanically to the wheels only at 40+ mph, traditional engine-braking--where the compression of the engine is resisting the rotation of the wheels--is not a viable option.

My theory is that when the battery is fully charged and traction motor is acting as a generator to provide regen braking, the Clarity starts the engine and uses the starter motor/generator to dissipate the excess electricity by opposing the engine's torque. Evidently (to me), this is the only way to explain how starting the engine can use up excess electricity.

In contrast, Honda's non-plug-in i-MMD hybrid cars use up power that cannot go to the fully charged battery by shutting off the engine's fuel injectors, closing its valves, and forcing the starter motor/generator to turn the resisting engine. So why doesn't the Clarity do this, too, instead of burning fuel to waste excess electricity? The only reason I can come up with is that the Clarity's greater weight requires the car to waste more regen electricity during pseudo engine-braking than the current Accord Hybrid or Insight.
 
@leop -

I’ve noticed this behavior as well, and I have NOT gotten the software updates yet.

I’m not sure what’s going on either, though I have noticed (based on the power flow diagram) that the engine is sometimes running and sometimes in EV mode, based on the IC display.

However the “dashed” lines remain on, for whatever reason the engineers decided....

Being that you have a scanner hooked up to the OBDII port, does it have anything to do with a coolant temp that rises, cools again (due to t stat opening) before rising?

-Skip


Sent from my iPhone using Tapatalk
 
I have noticed that as well. For me it happens during the “no regen allowed with a full battery” scenario. On two occasions when I have had to brake hard immediately after a full charge charge, the ICE has come on and the power meter turns to all dashed white. The ICE runs for less than 5 min and turns off by itself. However, the dashed white does NOT turn back to blue even though it goes back to EV and the engine icon is off. I think this is a software miscoding or bug. Upon restart it’s back to blue. I notice a 2 mile loss of HV range estimate and a gain of 0.1 max on my hour meter when this happens.
I don’t worry about this any more since I feel like it’s just an incorrect display and the car is acting normally.
 
insightman said:
Because the engine can be connected mechanically to the wheels only at 40+ mph, traditional engine-braking--where the compression of the engine is resisting the rotation of the wheels--is not a viable option.

My theory is that when the battery is fully charged and traction motor is acting as a generator to provide regen braking, the Clarity starts the engine and uses the starter motor/generator to dissipate the excess electricity by opposing the engine's torque. Evidently (to me), this is the only way to explain how starting the engine can use up excess electricity.

In contrast, Honda's non-plug-in i-MMD hybrid cars use up power that cannot go to the fully charged battery by shutting off the engine's fuel injectors, closing its valves, and forcing the starter motor/generator to turn the resisting engine. So why doesn't the Clarity do this, too, instead of burning fuel to waste excess electricity? The only reason I can come up with is that the Clarity's greater weight requires the car to waste more regen electricity during pseudo engine-braking than the current Accord Hybrid or Insight.
Click to expand...

And what then does a BEV hybrid do to dissipate excess energy? As it doesn’t have an engine? And in my mind why would they wastefully start the engine and burn gasoline, instead of just eliminating Regen and using the friction brake system for the first few stops?

I guess I don’t buy into this theory as I see no point in it....

Also when decending long mountain grades I notice at times Regen stops working, presumably cuz it’s charging the battery too fast...and in these circumstances the engine does not start itself to dissipate this excess energy being consumed....it just stops the Regen power and in my estimation relies heavier on friction brakes.

I don’t know the answers...but also not buying that Honda is choosing the start the engine for no other reason than to eliminate “too much” electricity. It just seems senseless to me. The computer can more easily and economically just flip a switch to disconnect battery during such times, to protect it from an overcharge.
 
craze1cars said:
And what then does a BEV hybrid do to dissipate excess energy? As it doesn’t have an engine? And in my mind why would they wastefully start the engine and burn gasoline, instead of just eliminating Regen and using the friction brake system for the first few stops?

I guess I don’t buy into this theory as I see no point in it....

Also when decending long mountain grades I notice at times Regen stops working, presumably cuz it’s charging the battery too fast...and in these circumstances the engine does not start itself to dissipate this excess energy being consumed....it just stops the Regen power and in my estimation relies heavier on friction brakes.

I don’t know the answers...but also not buying that Honda is choosing the start the engine for no other reason than to eliminate “too much” electricity. It just seems senseless to me. The computer can more easily and economically just flip a switch to disconnect battery during such times, to protect it from an overcharge.
Click to expand...

They have a patent for this, so it is something they can use. It was posted in another thread. You have to have a means of dealing with descending a mountain otherwise your brakes will be gone. An ICE vehicle just uses engine braking to save the brakes. It is recommended to charge an EV only partially for general use, so people who live in the mountains don't fully charge their battery, otherwise they will eat up the brakes.

Here is general discussion among some owners, they see regeneration turn off and don't fully charge their battery for general practice.

https://www.quora.com/What-happens-when-Tesla-Model-Ss-battery-is-full-and-it-is-going-down-hill
 
One simple thing would help this out, as I think it is intentional, is that for the whole time the car is in this weird mode show it on the i-MID and the reason why. The Pacifica shows the fuel and oil refresh mode in progress.


If the full battery regen DOES start the gas engine tell us that (Gas engine running to dissipate excess charge).

For car starting with REGEN with full, it MIGHT be that the car is programmed to do this to maintain the same total power of braking due to how the brake system was sized.

No regen available engine braking is the most perplexing mode. They also may start the engine due to some sort of oiling requirements. If the oil pump was electric it could be brought online to build pressure and then the engine could open all valves and power from the traction motor could be shunted to the starter generator to spin the engine over with a fully close throttle butterfly (if there is one) without ever firing the injectors. As there is no combustion occurring they should not need to warm up the engine to burn off condensation, and there shouldn't be any oil dilution from fuel.
 
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ab13 said:
They have a patent for this, so it is something they can use. It was posted in another thread. You have to have a means of dealing with descending a mountain otherwise your brakes will be gone. An ICE vehicle just uses engine braking to save the brakes. It is recommended to charge an EV only partially for general use, so people who live in the mountains don't fully charge their battery, otherwise they will eat up the brakes.

Here is general discussion among some owners, they see regeneration turn off and don't fully charge their battery for general practice.

https://www.quora.com/What-happens-when-Tesla-Model-Ss-battery-is-full-and-it-is-going-down-hill
Click to expand...

This I agree would make some sense if it is starting the engine as a safety feature to allow engine braking on long descents to prevent a brake failure...but not for the purpose of just dissipating excess electricity and protecting the battery as I’ve seen mentioned here quite often. Then of course it continues running for a while if the engine fires, just for warmup and lubrication purposes. What doesn’t make much sense to me is that with a single fixed high gear like the Clarity has...no transmission, and such a small engine...any engine braking offered would be extremely minimal in such a circumstance...and as soon as the engine gets down to idle speed it is possibly pushing the car instead of assisting with stopping. My truck has grade assist engine braking built in when towing large trailers down hills...the trans aggressively and automatically downshifts as you descend and the engine gets pushed near redline the whole way. This offers engine braking and prevents boiling of brake fluid from heat buildup of friction brakes. But Clarity can’t do anything like that, without a transmission.
 
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craze1cars said:
This I agree would make some sense if it is starting the engine as a safety feature to allow engine braking on long descents to prevent a brake failure...but not for the purpose of just dissipating excess electricity and protecting the battery as I’ve seen mentioned here quite often. Then of course it continues running for a while if the engine fires, just for warmup and lubrication purposes. What doesn’t make much sense to me is that with a single fixed high gear like the Clarity has...no transmission, and such a small engine...any engine braking offered would be extremely minimal in such a circumstance...and as soon as the engine gets down to idle speed it is possibly pushing the car instead of assisting with stopping. My truck has grade assist engine braking built in when towing large trailers down hills...the trans aggressively and automatically downshifts as you descend and the engine gets pushed near redline the whole way. This offers engine braking and prevents boiling of brake fluid from heat buildup of friction brakes. But Clarity can’t do anything like that, without a transmission.
Click to expand...

It's not mechanical, it burns off the excess battery charge by turning the ICE so the regeneration braking is still available. That's not even an option on a BEV, unless they burn the power into a heater or cooling fluid, which I don't think is common at all.

This issue is the vehicle doesn't know what the situation is so it may always assume a long decent, even if it's only a very short downhill. It should offer a means of cancelling before it starts this mode.
 
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I guess I simply don’t understand this at all. maybe we’re talking about 2 things at once.

But what is making no sense to me appears to be making sense to a couple others so there is some sort of disconnect here, for me anyway, cuz I’m not making any sense out of much of what’s being said in favor of the theory of starting and running the engine in order to burn off excess electricity.

And in my experience going down a long and steep 12,000 ft mountain grade, Regen chevrons eventually wouldn’t hold, and the engine did not turn on. Why not? Was it supposed to?

Even if it did, how would “turning the ICE” burn excess battery? And if looking at the gauges, this is the time during which regenerative braking is being restricted/limited, because the battery is either full or being charged too quickly.
 
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