gas engine coming on at low speeds with full charge

Discussion in 'Honda' started by Cay, May 6, 2018.

To remove this ad click here.

  1. Cay

    Cay New Member

    I've had two episodes recently where my Clarity was in Eco mode, with a full or mostly full battery and the gas engine came on inexplicably. The first time was several weeks ago. I was stopped at a light and all of a sudden the engine came on and stayed on for a mile or two after I pulled away from the light, before switching off and back into EV mode. As it should have never come out of EV mode while stopped, much less on a full charge, I had the dealer look at it and they ran a diagnostic and checked Honda's internal forums and found nothing.

    This afternoon, I floored it up a small hill in Eco mode kind of just playing around and the engine kicked in, as expected. But then it wouldn't go off. For the next 15 minutes, the car would not flip back into EV mode, even though I was driving 35 mph in Eco mode with 75% battery charge and using the regen paddles. Finally, when I thought I was going to have to pull over and turn the car off and then on again, it suddenly switched back to EV mode and then worked fine for the rest of the drive home (15 miles).

    Thoughts? Similar experiences?
  2. To remove this ad click here.

  3. Kendalf likes this.
  4. Viking79

    Viking79 Well-Known Member

    Yes, both well covered.
    1. Appears to only happen at full charge and braking or coasting (in regeneration mode)
    2. Appears to run the engine until fully warm, it will return to EV after 10 or 15 minutes.

    We don't know if these are bugs or normal operation, so taking it to Honda is good, but you might need to push dealer to report issue to Honda. Don't expect an immediate fix or anything.
    Johnhaydev likes this.
  5. bfd

    bfd Active Member

    The fix is an EV only button, but that is not going to happen in Clarity 1.0. Even then, when the electrons have nowhere to go because the battery is at capacity, something must be done to accommodate them.

    I think expectations that the car is an EV only vehicle until EV range is used up is what's bothering some owners… those who've had prior experience with PHEVs know this already.
    MZ5 and Johnhaydev like this.
  6. lisaandadam

    lisaandadam New Member

    I disagree bfd, with both of my Chevy Volts (MY 12 and 13) they indeed remain in all electric and the engine only comes on when the battery has been fully depleted, you tell the engine to come on, it's extremely cold, or the gas is over a year old (and even then you can delay if for a little while). Based on that experience I believe it's completely acceptable to expect the engine to not run while there is sufficient battery charge available.
  7. To remove this ad click here.

  8. Viking79

    Viking79 Well-Known Member

    Volt does run on gas more than my Clarity in winter, especially early Gen 1s that start the engine at 25 degrees. However, in practice the Volt and Clarity fill the same need. People that don't want to burn any gas should buy a BEV.
    bfd likes this.
  9. marshall

    marshall Well-Known Member

    My Hyundai Sonata will stay in EV mode until the EV range is used up. It has a HEV button, but EV mode is the default. When calling for cabin heat, the gas engine comes on since the car has no PTC electric heater, however the car is still being powered by the traction battery until used up. The car will temporally fire up the gas engine under maximum acceleration.

    Clearly, Honda is doing something different and is doing a poor job of explaining of what is normal operation.
  10. Roy2001

    Roy2001 Member

    Is is down hill when engine was on?
  11. bfd

    bfd Active Member

    The to mfgr's PHEV systems are different and have different operational parameters. I might add that Toyota's PHEV system added an EV only parameter after much complaining by early adopters of their PHEV 6 years ago. Didn't help the early adopters, but it did help later adopters.
    MZ5 likes this.
  12. To remove this ad click here.

  13. Ray Fragola

    Ray Fragola New Member

    According to the online "" the Clarity gas engine will automatically come on after not being used for awhile to lubricate the engine. This tutor can help answer some questions.
  14. Ben Washburn

    Ben Washburn Member

    I'm not sure why you'd want a true EV only mode anyhow. It may happen only once a year, and maybe even entirely through personal misjudgment, but there will come times when you want the car to deliver as much power as it can possibly produce. As long as that transition point is truly near emergency level high I don't see a problem with at least theoretically having it there.
  15. rickyrsx

    rickyrsx Active Member

    Mine has been doing that more lately too. I've had the car for almost a year now and I don't recall it doing it as frequently during the winter. I drive mostly EV though so I've been thinking that the engine needs to run a little bit more now since it got used so infrequently the past 11 months. This is not backed by facts though, just a gut feeling.

Share This Page