Sudden hard acceleration starts ICE, but it won't turn off - why?

Discussion in 'Clarity' started by bbct, Apr 16, 2019.

  1. Mark W

    Mark W Active Member

    Interesting. When the engine ran for an hour, did the EV light stay on the whole time? Did your EV range and battery level stay the same? It sounds like the car is switching itself to HV mode.
  2. Tim66

    Tim66 Active Member Subscriber

    EV light stayed on but half circle on the Power/Charge gauge turned black. Switched the info display to the battery and saw the engine was supplying energy to the battery and, I assume, the wheels. I'll have to check next time to see if the ICE is only supplying power to the battery and not the wheels.
  3. KClark

    KClark Active Member

    No, the sign is that I have done this same commute, same route, same hills, same times, same temperatures, at 65mph with ACC engaged for 4 months in pure EV. (Yes, I know that there is no EV button you can push in a Clarity to force electric drive only but there certainly is a pure EV mode of operation, in other words, driving with propulsion only from the battery with no ICE assist.) And now suddenly my ICE is engaging for 5 days straight with no discernible reason why. The first day I thought it had something to do with not having the ICE run for 2 months, but that doesn't explain the subsequent 4 more days of ICE operation.
  4. Zor

    Zor Member

    I have found that fiddling with buttons after an auto on event causes weird behavior. One of them being that the engine shuts off after its warm-up and the system doesn't change back to 'EV mode'.

    If you go into the energy panel, the engine is not providing power. Its not charging the battery, but you have the white ticks and the lack of the green EV light.
    Pegsie likes this.
  5. fotomoto

    fotomoto Active Member

    One thing this is different is the driver. We're not machines and can't replicate everything perfectly every time. You might be driving the car harder and not realize it. Just throwin' out ideas and thoughts here. Try using ECON tomorrow.
  6. KentuckyKen

    KentuckyKen Well-Known Member

    Yeah, it would make sense and be good engineering to have a FMM, but my Clarity gives no indication of having one. Could be that it’s a feature but just not working in mine. Need more data.
  7. insightman

    insightman Well-Known Member

    Robert Mueller's not busy these days. Can we get him to investigate Honda and get all the answers we desperately seek?
  8. MNSteve

    MNSteve Well-Known Member

    We would get a report that contained all the data we already know, with the interesting parts redacted.
  9. KClark

    KClark Active Member

    No ICE yesterday but it happened again today, that’s 6 out of 7 days it has engaged after 4 months of daily commuting using only EV. Today for the second time in those 6 instances it engaged as I left the freeway and started slowing down on the off ramp. About 60% charge, was going 65mph with ACC on flat terrain. It ran for about 8 minutes, about 4 of those were at a dead stop in traffic, it ran and was charging the battery.
  10. KentuckyKen

    KentuckyKen Well-Known Member

    You’re not by any chance related to @bobcubsfan are you? (His ICE seems to run all the time.)

    Seriously though, your scenario is a puzzler and somewhat unique. I have no idea why some of our Claritys seem to have such different behaviors.
  11. AnthonyW

    AnthonyW Well-Known Member

    What is your charging regime. How often do you charge, to what level and on what type/level of charger? How far down do you run the battery pack and how often.

    Sent from my iPhone using Inside EVs
  12. KClark

    KClark Active Member

    Anthony I have a 44 mile round trip commute. I charge every night with the 120V charger at home. When I get home I usually have about 5 bars of charge remaining, about 10 miles EV left according to the dash display. On Friday night I usually charge for 3-4 hours which is enough for weekend errands and then charge fully on Sunday night, unless I know I’m driving a longer trip on Saturday, then I fully charge on Friday night. I've been doing this since I bought the car 4 months ago. As far as I can tell nothing has changed from my routine, the drive, the time, the route, the charging. For 4 months I have done this using only EV, I can't figure out why suddenly the ICE needs to run every day.
    Last edited: Apr 20, 2019
  13. Roger Lambert

    Roger Lambert Member

    Won't the second push on the HV button put it into HV Charge mode?
  14. insightman

    insightman Well-Known Member

    To activate HV CHARGE Mode, you have to hold the HV button down for a few seconds until the HV Charge LED on the dash comes on. Short presses of the HV button turn HV Mode on and off (and turn HV CHARGE Mode off).
    Last edited: Apr 20, 2019
  15. Today in SPORT mode I accelerated a bit too aggressively in EV mode getting onto I-75 and the ICE kicked on. And stayed on for several miles.

    What was curious is that when, as a goof, I hit the HV button, the ICE immediately shut down. Did not seem like a coincidence. Of course, shortly thereafter the ICE started cycling on and off periodically to maintain battery charge. When I went back to EV while it was cycled off, it stayed off.

    Just seemed a bit peculiar, but similar to other episodes I’ve read about on this forum.
  16. insightman

    insightman Well-Known Member

    I never try to understand HV--its magical behavior is difficult to predict. I'm still trying to get my head around the different HV Mode and HV-Mode/gear-mode set points people describe on this forum. Fortunately, I rarely need to use HV. As I've written before on this forum, I'd pay hundreds of dollars for an info display that shows the factors HV is assessing to make its decision to activate the ICE (Hybrid Drive mode), deactivate the ICE (EV Drive mode), and activate "gear-mode" (Engine Drive mode).
    Last edited: Apr 20, 2019
  17. Bina12834

    Bina12834 Member

    Do all those other cars that have FMM systems also have a pressurized fuel tank like the Clarity does to help extend the life of the fuel? I'm too lazy to look it up right now.
  18. insightman

    insightman Well-Known Member

    The Chevy Volt has a sealed tank and a vacuum pump. I don't believe the Prius Prime has one.
  19. KClark

    KClark Active Member

    Just an update on my ICE saga. Only a few short errands on Saturday but on Sunday went to my mom's house for Easter dinner, about 50 mile round trip. Traveled there on EV. On the way home I got on the freeway with about 50% battery. The traffic was moderately heavy so as I merged into traffic we were only going around 40mph. After 2-3 minutes of that the ICE came on again, for no apparent reason that I can discern. It stayed on for more than 5 minutes while we stayed at 40mph with many slow downs and slight speed ups.

    I wish there was a technical support email or phone for the Clarity. I'd love to have someone at Honda who knows what this car is about try and explain what is going on. I know I could go to the dealer but that seems wildly optimistic, I seem to know about as much as they do when it comes to Claritys.
  20. insightman

    insightman Well-Known Member

    Honda will always refer you to your dealer and your dealer can't get that kind of information from Honda--you can't win. I wish Honda would sell me an app for my center display that would show the factors the car is assessing to determine when to use EV Drive mode, Hybrid Drive mode, and Engine Drive mode. However, even though that app would illustrate why the car thinks it's appropriate to use each mode, it wouldn't cause people to be happy with what they consider unwarranted ICE activation. Honda probably thinks such an app would give them more headaches than kudos.

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