Behavior change in HV mode

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MNSteve

MNSteve

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I have had my 2018 Clarity for 13 months and 12,000 miles. My standard trip behavior is to run in EV mode for the three miles until I get established on the highway, shift to HV, and run in HV while I am driving on the highway. I often make the same trip on gently rolling Interstates at about 70 mph with cruise control engaged. Until a few weeks ago the car's behavior was consistent - after the switch to HV, it ran in "gear mode" (direct connect engine-to-wheels) much of the time, dropping out on some of the less-gentle hills and dropping briefly into EV on the downhill portion.

I first noticed a marked change in behavior a few weeks ago. Now, when I engage HV after getting established on the Interstate, the engine revs to a noticeable level. I don't have instrumentation that will give me RPMs, but I can hear the engine at a level of, pardon the technical term, "mildly annoyed bees". I was never able to hear the engine before. The info display shows the engine running and power flow back into the battery, and the gear icon never appears. If I drop out of HV mode for a minute, then press the button again to re-enter HV, the behavior reverts to what I would expect and what I have become accustomed to.

Additional information:
  • The period of time in EV to trigger the return to "normal" behavior needs to be about a minute; if I drop out of HV and then re-enter it in, say, 10 seconds, the engine revving behavior continues.
  • There is no observable effect on operation of the car, other than the whine of the ICE. It drives fine. There is plenty of power.
  • No software updates. I've had the oil changed, but I don't think my dealer even understands the concept of software updates, so I don't think that's an issue.
  • I don't think this is related to weather or any other factor like different roads or different driving parameters. It did not happen last Winter when the temperature changed; the route I am driving is the same and the speed set into the cruise control is the same. It happens regardless of wind, rain, or any other factor I can observe.
  • This operation is consistent. It has happened on every trip I have taken in the last few weeks after never happening during the first year of ownership. The operation is quite easy to observe; the engine revs to a noticeable speed, I switch to EV for a minute, then when I go back to HV the difference is obvious.
I would visit my dealer, but I know that their eyes will glaze over two sentences into my description, and they will refuse to even acknowledge the issue. And even if they did, the risk of them making things worse is higher than the chance of them actually fixing anything. I am considering the ever-popular re-boot technique of disconnecting the battery to see if that changes anything.
 
MNSteve said:
I have had my 2018 Clarity for 13 months and 12,000 miles. My standard trip behavior is to run in EV mode for the three miles until I get established on the highway, shift to HV, and run in HV while I am driving on the highway. I often make the same trip on gently rolling Interstates at about 70 mph with cruise control engaged. Until a few weeks ago the car's behavior was consistent - after the switch to HV, it ran in "gear mode" (direct connect engine-to-wheels) much of the time, dropping out on some of the less-gentle hills and dropping briefly into EV on the downhill portion.

I first noticed a marked change in behavior a few weeks ago. Now, when I engage HV after getting established on the Interstate, the engine revs to a noticeable level. I don't have instrumentation that will give me RPMs, but I can hear the engine at a level of, pardon the technical term, "mildly annoyed bees". I was never able to hear the engine before. The info display shows the engine running and power flow back into the battery, and the gear icon never appears. If I drop out of HV mode for a minute, then press the button again to re-enter HV, the behavior reverts to what I would expect and what I have become accustomed to.

Additional information:
  • The period of time in EV to trigger the return to "normal" behavior needs to be about a minute; if I drop out of HV and then re-enter it in, say, 10 seconds, the engine revving behavior continues.
  • There is no observable effect on operation of the car, other than the whine of the ICE. It drives fine. There is plenty of power.
  • No software updates. I've had the oil changed, but I don't think my dealer even understands the concept of software updates, so I don't think that's an issue.
  • I don't think this is related to weather or any other factor like different roads or different driving parameters. It did not happen last Winter when the temperature changed; the route I am driving is the same and the speed set into the cruise control is the same. It happens regardless of wind, rain, or any other factor I can observe.
  • This operation is consistent. It has happened on every trip I have taken in the last few weeks after never happening during the first year of ownership. The operation is quite easy to observe; the engine revs to a noticeable speed, I switch to EV for a minute, then when I go back to HV the difference is obvious.
I would visit my dealer, but I know that their eyes will glaze over two sentences into my description, and they will refuse to even acknowledge the issue. And even if they did, the risk of them making things worse is higher than the chance of them actually fixing anything. I am considering the ever-popular re-boot technique of disconnecting the battery to see if that changes anything.
Click to expand...

We must have the same dealer.
 
Could colder temperatures be the cause. My car (2018 with 20,000) behaves differently in colder weather than in the summer. The gear icon does not come on until the engine is fully warmed up.
 
Groves Cooke said:
Could colder temperatures be the cause. My car (2018 with 20,000) behaves differently in colder weather than in the summer. The gear icon does not come on until the engine is fully warmed up.
Click to expand...
As I said, I did not observe this behavior last Winter when the weather changed. I enduring the whining for 15 minutes to see if it would self-correct, and it did not. But putting the car in EV for a minute and then pressing the HV button brought it back to the expected behavior.
 
TomL said:
We must have the same dealer.
Click to expand...
I don't think I passed along this ringing endorsement of my dealer.

A few days before I took the car in for maintenance based on the maintenance minder bugging me, it started making a noise. It sounded like a stuck brake rotor - metal-on-metal, a clicking noise that was variable with speed, disappearing at about 30 mph. It didn't sound catastrophic, so I decided to point it out when I took it in since the appointment had already been set.

The dealer's answer: "Your car is supposed to make that noise." I am sure that they were referring to the low-speed pedestrian-warning sound, which is certainly not anything like a metal-on-metal sound. I decided that I was simply not up to fighting this level of cluelessness and that either the situation would get worse or it would go away. It took a couple of weeks, but whatever it was that was rubbing finally got worn down to the point that the noise stopped.

If they can't handle the concept of a grinding noise being different from "angels singing" I am not even going to try to explain EV, HV, direct couple, engine revving, and a difference from how it has operated for 12,000 miles.
 
I had the same thing happen to my Clarity (2018, purchased 2/2018) after the software update done in October, 2018. The Clarity would no longer go reliably into gear mode (direct drive mode according to the Owners Manual) when initially switched to HV mode for freeway driving. Switching to EV mode and back to HV mode after the engine warmed up allowed the gear mode to function. However, I used an OBD dongle to observe the rpm. It is interesting that even when the gear mode was not shown, the engine rpm was still near that which would occur if gear mode was in operation. I say near because the rpm still fluctuated a bit more than if the gear mode was shown on the display. The energy flow diagram looked similar, too, for both when the gear mode was shown and not shown.

In our case, after a while (10-15 minutes), the gear mode mode would come back even without the in and out of EV trick.
 
I haven't had this exact scenario, but have in the past noticed unexpected behaviour. Investigation showed that my wife had taken it out of 'eco' mode on her trip. Is that the culprit perhaps? The missing icon is not that conspicuous.
 
leehoewonek said:
I haven't had this exact scenario, but have in the past noticed unexpected behaviour. Investigation showed that my wife had taken it out of 'eco' mode on her trip. Is that the culprit perhaps? The missing icon is not that conspicuous.
Click to expand...
I will play with ECON and see if that helps. Thanks for the suggestion.
 
leop said:
In our case, after a while (10-15 minutes), the gear mode mode would come back even without the in and out of EV trick.
Click to expand...
I suppose I should try waiting longer, but my patience has been limited based on my annoyance.
 
Kerbe said:
At 3 months and just over 6000 miles - including a 3200 mile trip on mostly interstate highways - I've never seen a "gear icon". Where does it appear? Can anyone post an image?
Click to expand...

upload_2019-11-20_20-22-50.webp
 
Kerbe said:
At 3 months and just over 6000 miles - including a 3200 mile trip on mostly interstate highways - I've never seen a "gear icon". Where does it appear? Can anyone post an image?
Click to expand...
It also appears similarly on the info screen on the tablet display.
 
Phil_Meyers said:
What's so important about gear mode?
Click to expand...
Nothing really, unless you’re embracing your inner geek mode like many of us on the forum. However, as it does mechanically link the ICE to the wheels, it provides a one to one engine rpm correspondence to speed so it sounds more like what people are used to in a gas-mobile.
We all assume that it’s the most efficient HV method since why would Honda add that much cost, weight, and complexity if it didn’t have some benefit.
 
MNSteve - I had about a six month period of time where the gear mode never appeared. I mean not rare occurrence, just never. It happened after I had encountered the system power problem using a charger away from home and without SB18-079 (or SB18-097).

In my case, this situation caused EV range to go down slowly even in HV mode. I realize that's not normal, but that's what happened. i.e. On my standard 109mi trip from Eugene to PDX (OR), my car's EV range would bottom out even with HV selected. I'd then long press HV and get charge mode, which did recover the EV range to 55% or whatever that one is.

Anyway, during this time KentuckyKen suggested the 12v battery disconnect "reboot"-- I tried it, and my gear mode appeared. I had literally never seen it before because the system-power issue happened on my first trip in the new car. Anyway, post reboot, my car now will engage gear mode when it can.

So not sure if any of this matches-- it sounds like you get it less often rather than never, but you might try it. You do see a bunch of scary messages post-reboot but they automatically clear if you drive the car like 10 miles or whatever.

-Dan
 
MNSteve said:
I've had the oil changed, but I don't think my dealer even understands the concept of software updates, so I don't think that's an issue.
Click to expand...

Ever since I read this thread (https://insideevsforum.com/community/index.php?threads/1st-oil-change-engine-louder.7491/#post-85118) I have been wondering if having an oil change cause the ICE to come on more than expected for a while.

After I got my first oil change last month, it seemed to me that the ICE came on "inappropriately" and stayed on longer than expected. That behavior seems to have dissipated and on my last trip it seemed to be back to "normal".

It occurred to me that maybe after an oil change the engine runs in a quasi maintenence mode to make sure the new oil is fully circulated through the system.

Thoughts?
 
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