free IMA update for HCHII 2006-08 from American Honda

Discussion in 'Honda Hybrids' started by hunter44102, Jul 30, 2010.

  1. Sledge

    Sledge I like owls with captions

    I just got my recall notice. I'm scheduled to get it done on the 12th. From the description, I expect the car to give even less assist than it does now and get less mpg.

    On the brighter side, I'll be more motivated to trade it in and get something else.
  2. cakes

    cakes Member


    I got a call back from a Honda representative. I had asked what this part of the letter means:

    I was a little confused by the representative's explanation (she was repeating what she was told by a technician, and I think something got lost in transation), but I think the gist of it is that in auto-stop mode, when there are 1 or 2 bars on the battery gauge, the engine will sort of randomly start back up on its own even while you're still stopped. Apparently this currently only happens when there is 1 bar on the gauge. Does that sound right to anyone?

    She also said fuel economy will take a hit, but the difference should be negligible.

    Also, if you elect not to get the update, it does not affect your warranty in any way.

    Last edited: Aug 5, 2010
  3. greenrider

    greenrider Well-Known Member

    With the letter I got this Monday, they kind of did. Honda did admit that higher ambient temps, in addition to stop/go driving, could cause a premature deterioration of the IMA battery. From what my wife who has mostly driven the car for the last 11 months tells me, we may already be there--or would have been with an IMA light had it not been for the 3 previous SW updates.

    I took it as "we know that we very well will have to fork out some serious cash to repair/replace IMA batteries in the future so hopefully this will at least maintain battery function for an acceptable period so that we don't look quite as bad. SW updates, even free, are still cheaper than IMA battery swaps.

    Perhaps enough people filled out complaints with the NHTSA re: loss of power and IMA functionality that Honda was compelled to take action to avoid an embarrassing situation or the potential of a forced recall? Whatever the reason, it's a big enough deal for Honda to actually call owners and solicit them to bring their cars in for service in addition to the usual letter in the mail.

    Personally, I don't really care what Honda does be it replace the IMA battery or system, SW update, an improved cooling system for the IMA (why draw cooling air from one of the hottest places in the vehicle?). I just hope the IMA system functions normally (i.e. similar or the same as it did in the 1st 18 months of ownership) when I get it back. My fingers are crossed while I wait for word from the dealership today...

    FWIW, I did a "power reset" last week and the sx did largely subside for awhile (this was the first major IMA crash for me today since the reset last Friday).
    Last edited: Aug 5, 2010
  4. greenrider

    greenrider Well-Known Member

    Remember, it's not a recall, because that would be an open admission that there is a problem that could potentially pose a hazard. This is an update (whatever difference that makes, practically speaking).
    Ditto for me on the last line, though.
  5. greenrider

    greenrider Well-Known Member

    After the number of sw updates my HCH II has had, it's surprising that Honda hasn't attempted to come up with some form of hardware revision, add a fan (thee's a circular hole with attachment points right where the duct work from the IMA case terminates behind the trunk lining) or something to improve the thermostatic conditions within the IMA. Manipulating charge/discharge cycles can only go so far. Doesn't the Prius draw cool air from below the rear seat cushion closer to the floor?
  6. 06hch2

    06hch2 Well-Known Member

    i'm satisfied with my car's performance and am not going to do the update. if it ain't broke, don't fix it.
  7. Harold

    Harold Well-Known Member

    Has anyone in Canada received this letter? H
  8. Jess

    Jess Well-Known Member

    Did anyone else get PM'd by an LA reporter wanting to discuss the IMA software updates and how it' affecting customers?

  9. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

  10. hunter44102

    hunter44102 Well-Known Member

    I had the update performed yesterday morning. The papwerwork says they updated the battery software and A/T software (also worded: updated auto trans system and PGM FI system). I'm assuming the battery software is in the PCM.

    They also started a 'Clutch learn', 'CPK learning' and 'PCM Idle learning'

    I drove it home for 7 miles but didn't notice much. It still gave me plenty of assist when I needed it. I will find out more tomorrow when I do my commute.

    Every person I talked to called it a 'recall' even though I never mentioned the word on the phone or in person. They are treating it like a re-call.
  11. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    A service writer at our dealership has referred to it (via email) as the "US Recall". I had just asked regarding the "software updates". He also mentioned being in touch with "Honda Engineering".
  12. hunter44102

    hunter44102 Well-Known Member

    Maybe they haven't had as many failures in Canada because of the cooler climate. The article said the rate was 4% failure - wasn't sure if that was California only, or all of the U.S.

    I just drove the car and -did- notice that assist still happens in the same situations, but the bars are just less. I haven't tried it, but I'm guessing if I really floored it, I would get the full assist if I needed it.

    I think they just tweaked it so that normal stop-n-go doesn't keep pulling a full assist every time you tap the pedal. I complained about this over a year ago during some un-avoidable construction - my battery would drain quickly during stop-n-go, and I had no way to control it because the assist was so strong at slower speeds.

    So this update is a great thing for stop-n-go hypermilers who don't want to empty the battery after only a couple miles of stop-n-go
  13. greenrider

    greenrider Well-Known Member

    That's the one thing I've noticed, that I'm still getting a lot more assist than I expected.
  14. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    I've been thinking about the philosophy behind the Civic Hybrid, a few ideas:

    The primary reason for good mileage with this car is it's quite small engine displacement: 1.3 liter, vs 1.8 liter (I think?) for a regular civic. There are several things used to improve performance with this small engine: dual spark plugs (with strategic timing), variable lift cam lobes (normally low lift, but more generous under heavy load conditions), and electric motor assist.

    The latter's primary purpose is to "bootstrap" you out of inertia, say from as standing start, or any time you need a burst of acceleration. Once that is done, it should back off, and let you complete the acceleration exclusively (or nearly so) via the engine.

    I don't know that making the electric motor a little more miserly is going to degrade mileage. Maybe just slightly. Depending on your driving style. Maybe more so it will impact performance, and again only slightly.

    Just thinking "aloud", and starting to ramble ;)
  15. hunter44102

    hunter44102 Well-Known Member

    My concern is the battery. How does it affect mpg and acceleration over the time it degrades?

    If the government did a test with a new 2006 HCHII and got 45/40 MPG, what happens when you do the same test after 4 or 5 years and 85k miles later?

    If the battery capacity is down to 25% of its original capacity, what is the loss in MPG? Or is it a loss in performance since the assist will not last as long and the system will spend more time charging?

    I believe the assist motor is only as good as the battery that drives it (the remaining capacity).
  16. ematzen

    ematzen Well-Known Member

    Good points. I can only speak from experience, so here goes. My 2006 HCH has a degraded battery that significantly decreases the observed MGP. The main reason that this happens, based on my observations, is because the battery is frequently totally drained, forcing a slow recharge. This recharge significantly impacts the MPG.

    As the battery degrades, these forced recharges occur more and more often. The honda software doesn't do a good job of "maintaining" a charge in a degraded battery, so the SOC goes from empty to full to empty to full to empty to full many times during the drive, even with no major battery load required.

    If the battery didn't constantly cycle from empty to full, the fuel economy would be significantly improved. My car gets great gas mileage when the battery is full. But it doesn't last.

    So. In my opinion, based on real-world driving, degraded battery (even one without an IMA error) = decreased MGP.

    HCH 2006, average 32mpg. No AC. No lead foot. Pouting driver.
  17. cylverbak

    cylverbak Member

    Hi Harold, I can confirm that Canada is included in this update. Just received mine from Honda Canada. The text sounds the same as has been reported here from American Honda.

    I'll phone my local dealer tomorrow. I too am wondering how much of a hit I'll take in the mileage department. Haven't decided whether this will save my battery or just push replacement through the warranty period. Gads I'm getting cynical.
  18. Mendel Leisk

    Mendel Leisk 2010 Prius (CAN Touring) Staff Member

    D.O., just got our notice out of the mail box.

    In for a penny, in for a pound.
  19. SentraSE-R

    SentraSE-R Pishtaco

    The LA Times article sums up the concerns pretty well. I suspect that those who hypermile by using the Atkinson-cycle engine to best advantage will never notice a mpg drop. Those who dip into their SOC regularly are going to see their mpg drop. My brother owns an HCH and took it in for the "upgrade." He noticed more change (loss) from the new tires on his car.
  20. hunter44102

    hunter44102 Well-Known Member

    So far, after 5 days, I have not noticed a drop in mileage, even when running A/C.

    Also, I have not had an incident of lost power when entering the highway and the battery drops out, so its possible that they fixed that issue. This would have happened to me by now with the old software

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