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

  • Thread starter Thread starter bbct
  • Start date Start date
  • Replies Replies 100
  • Views Views 16K
Exactly my issue. After the ICE engages (pedal past the detent) I've tried pushing the buttons to disengage or done nothing and it remains on. I've waited for several miles to go past the detent in EV mode and ICE engages but won't shut off, no buttons pushed (stayed on for an hour until I exited the freeway, got home and shut off the engine). I reported this issue and the stuck HV range to the dealer. They said both issues were fixed. But only the stuck HV range issue was corrected. I've engaged the ICE below 40 MPH and above and it always stays on no matter the SOC or length of operation. The service guy said it wasn't supposed to work that way. Back to the service department.
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.
 
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.

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.
 
This might be your sign. Too much throttle at too high of speed (highway?), can be a trigger. Remember, there is no pure EV mode in the Clarity.



Normal hybrid power flow behavior once the ICE is running.

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.
 
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.
 
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.

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.

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.
 
I spent some time searching but will readily admit my internet search skills are lacking and couldn't find any specific mention of it. But no denials either. So, the question remains.....

I did find that Pacifica minivan plug-in has a 90 day limit. It would be very unusual that one of the longest range PHEV's, which is the most likely to avoid gas usage, doesn't have FMM. <shruggs>
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.
 
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.
 
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.
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.
 
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
 
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:
Walt - while that sounds feasible, I don't think that is the case. It happened again today. I had over half a charge, about 23 mile EV range. I got on the freeway, and the ICE kicked on the same way I originally described. It would have run the whole way home, but I was pushing buttons trying to get it to turn off. At a light, I put it in HV mode. The blue line showed up and the engine shut off. I started moving slowly, still on electric, the top icon said Ready EV. I pressed the HV button to turn HV mode OFF (which should put me in pure EV mode, I've got plenty of battery). Instead of the blue line extending further, it disappeared and the engine turned on. I put HV mode back on, the blue line appeared and the engine shut off. The entire rest of my drive, when HV mode was on and I was hardly accelerating, Ready EV showed and the engine shut off. But every time I turned HV off, the blue line would turn all white, it would say Ready (no EV) and the engine would start up again. This was the case for my entire 15 minute drive home. When I stopped to park the engine was running, charging my battery. It burned very little gasoline, but my range on fuel came down a couple miles. I think I'll call the dealer and ask if there is some sort of software glitch they know about.

I cannot think of any reason, with over half a battery charge, that turning off HV mode should turn ON the engine under virtually no load, especially when the engine started out OFF in HV mode.

Won't the second push on the HV button put it into HV Charge mode?
 
Won't the second push on the HV button put it into HV Charge mode?
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:
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.
 
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.
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:
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.
 
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.
 
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.
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.
 
Back
Top