[swhitevt]

Hi folks,

I have a 2000 red Insight that I bought used in October 2004. Except for a brief test drive of a CVT Insight last Sept, this is the only Insight I've ever driven, so my judgement of what's normal and what isn't is shaped by my limited experience.

I had noticed that it seemed that the Assist was somewhat weaker/shorter duration than what others on this list described, but hadn't thought much about it. I had also observed that the car would sometimes (often?) stall in autostop. The battery charge indicator would usually stay high (17-18 bars), but would rarely discharge below 16 or 17 except in a (rare) recal.

Then this Tuesday as I was driving to work the Check Engine and IMA lights both came on. I pulled off the road, looked in the owners manual, and decided it would be safe to drive the car the 5 miles to the Honda dealership. They hooked it up to the computers and discovered that I need a new IMA battery and a new control module! I said, that's under warranty, right?, and they checked and agreed that it was

So, they've got the parts on order, and until then, they say that according to everything they can find, it is fine for me to drive the car around without the IMA system.

This has led me to some observations and questions:

1) Is it true that it's fine to drive the car w/o IMA active? it seems to run fine but no charge and assist, and no autostop.

2) I have noticed that, in fact, the driving experience in this car since the IMA quit is almost the same as it was before. This leads me to believe that the IMA wasn't functioning well ever since I got the car. I do miss the regenerative braking and autostop that I had before the IMA quit completely, but I realize that I was rarely getting any assist anyway.

3) Mileage. Almost unchanged. I drive uphill to work in cool temps, downhill home in warmer temps. In this weather (highs 70s F, lows 40s), I usually get 55 mpg to work, 77 mpg home. The past few (warm-ish) days w/o IMA I have gotten 53 mpg to work, 81 home.

I had assumed that my OK but not stellar mileage was due to 1. cold weather (remember, I've only had this car during winter/spring) and 2. mountains (I've only driven it in Vermont and New Hampshire). Now I'm wondering if I've been basically driving a non-hybrid Insight all along.

4) So, if that's the case, what should I expect when I get my new IMA battery? I'm speculating that my downhill trip will be unaffected by the IMA battery (gravity and aerodynamics do all the work), but that my uphill trip mileage may benefit, since I'll be able to use assist rather than downshift a lot to get up the mountains. Does this make sense?

I'm also fascinated that a non-hybrid Insight can easily average 65 mpg (in the springtime, in mountains)--that I can get the EPA mileage without even having a hybrid car...

5) Has anyone else here driven their Insight without any IMA? how does this experience compare to driving a "normal" insight?

As far as the car's history: I bought it on ebay. It was a single owner car, bought by a dealer to resell. It was from southern Georgia, so the battery had been stressed with a lot of hot weather, I'm sure. When I got it, it had 36K miles, with a LMPG of 50.9 (I know, pretty bad). Prev. owner did all the routine recommended maintenance at her local Honda dealership--I have the receipts. Since I got the car I've driven about 6K miles.

So, anyway, thanks in advance for any answers, observations, or input, and sorry for the somewhat long and rambling post.

Sara White
Hartland VT

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[Insightful Trekker]

Hi Sarah and thanks for the post :!:

1) the maximum MPG comes from driving without the need for assist so no IMA should be OK as long as _some_ moderate output is available for the DC-DC converter to supply all the needed 12v. If not and in some types of IMA faulure then the car will soon be "dead".

2) Difficult to say. On most any uphill assist should have been indicated if you pressed hard enough of the gas.

3) See #1 above

4) Makes sense but the IMA is really there to allow for a power boost and a smaller more MPG capable engine. YMMV

5) There have been a few posts in regard to loss of IMA and different driveability issues but none in depth AFAIK.

I hope yours is the first to enlighten the group :!:

And I am looking forward to reading your follow-up in this thread. :!:

 

[atlaw4u]

Keep us posted as to any changes after repair. I am interested to read the difference.

 

[swhitevt]

I just got the new battery pack on Tuesday. They also replaced a control module. It turns out this is the first Insight battery the dealership has ever had to replace. (not that the roads around here are swarming with Insights...)

Having a fully functional IMA is like learning to drive the car all over again! The old battery pack was definitely very weak the whole time I've had the car, so I feel like I'm back down at the bottom of the driving learning curve.

I can't yet compare my mileages before and after the battery pack replacement, since the day it was replaced the temperature dropped 30 degrees F and it started raining and has been that way ever since :? If the weather predictions for the upcoming week are true, I should have a good point of comparison to my time without IMA with the same temps and no rain, and I'll post that.

During one week of no-IMA driving, I went 212 miles with 66 mpg average. This was driving my usual routes, half highway, half backroad, all paved, elevations 400-1250 ft, outside temps 75-85F.

Most big hills on the highway required 3rd gear w/o IMA, and now with the new battery they're possible in 4th. The driving experience wasn't bad--maybe a bit Geo Metro-like for my taste, but I never had any trouble reaching or maintaining any speed I wanted to.

One thing I really miss now that I have my good battery is being able to go into fuel cut mode down certain moderate hills. With the IMA working, the charging that starts as I lift my foot off the gas slows me down enough that I'm losing speed downhill, so I have to either give it a little gas, or decide to coast (and lose my regen and still burn fuel...). Without the IMA, these moderate hills were perfect for no gas/ no brake while maintaining speed.

On the steep curvy hills, the regen is great, because the slowing that it causes is just the right amount to keep me at a constant speed without even touching the brakes.

I like having the IMA start the car again, since the 12V starts were a bit noisy. Also there had been a few times when I had to try more than once to start the car with the 12V. I realized in retrospect that I had been getting 12V starts for the entire month before my IMA light went on.

Speaking of 12V, it didn't die during the 2 wk I had no detectable IMA, although the 12V battery warning light (and simultaneously the emergency brake light) did appear two or three times during the last few days of no IMA. Each time it occurred I was driving without any unusual 12V load (radio on, lights and wipers off), and there was no change in the sound or feel of driving the car (it didn't stall or anything). The light turned off each time within less than a minute.

My not-bad experience has made me think that driving an Insight as a permanent non-hybrid could be an acceptable alternative for someone whose battery dies when it is no longer under warranty. From Insightful Trekker's comment about the DC/DC converter charging the 12V, I suspect that some charging modification would be necessary if one were to drive long-term with a dead 144 V. I don't know electrical engineering: how complicated would a mod like that be?

Also, if one weren't using any of the hybrid capabilities of the car, could the dead 144V, control modules, etc, etc, be removed for a lighter car with more interior space?

Not that I'm planning on it anytime soon, but years from now, who knows?

Anyway, I'll update more later as I learn how to drive my "new" hybrid car, so I can compare my non-hybrid experience to something the rest of you are driving.

Sara

 

[devin1955]

Hi Sara,
Guess I'm a bit late with this, but I didn't see your post until now. I too recently had the IMA and Check Engine light illuminate on my 2000 5-speed, and it's in the shop as I type this. I'm crossing my fingers for the same repair you got, since I have 70,000 miles on it.

1. I drove mine about 15 miles home after the "event" and then about 40 miles to my dealer to drop it off. I believe there's no problem in doing so, you just don't get the benifit of the IMA system as you know.

2. My experience (in the 2 months I've owned the car) that the IMA system does most of it's work when you accelerate from a stop. During normal driving, it doesn't do a thing for you unless you climb a hill or get on the gas to speed up as in passing. I noticed the car was quite a bit more slugish accelerating from a stop without the assist.

3. Same here. The mileage wouldn't change all that much, especially if you're not doing stop-and-go driving. On the highway, there would be virtually no difference.

4. I think your assumption here is absolutely correct.

5. In stop-and-go city driving, there's a very noticeable difference. On the highway, virtually none.

Hope this helps.

 

[greytop]

Hi,

Our IMA stopped working some weeks ago, been driving on petrol engine only.

Our local Honda dealer charged us £255 for diagnostic check and informed us the IMA BCM required replacement.

Dealer wants £1500 to replace, we do not have that sort of cash, does anyone know how much the BCM module costs in the USA

many thanks

 

[chrs]

My not-bad experience has made me think that driving an Insight as a permanent non-hybrid could be an acceptable alternative for someone whose battery dies when it is no longer under warranty. From Insightful Trekker's comment about the DC/DC converter charging the 12V, I suspect that some charging modification would be necessary if one were to drive long-term with a dead 144 V. I don't know electrical engineering: how complicated would a mod like that be?

Very interesting. I think it would be quite feasible. The type of motor used for the IMA needs a sophisticated controller to act as a motor, but not to act as a generator. So it would be possible to put a relatively simple rectifier on it to produce dc, and then perhaps use the existing dc-dc converter, or, if that doesn't work, add a new dc-dc converter, to charge the 12 V battery from the higher voltage produced by the IMA motor.

And yes, that would allow removing the battery and some of the controls for more interior space--the rectifier would take very little space.

Charlie
West Lebanon, NH

 

[Dougie]

Temporary shutoff?

Can you shut off the battery (with the big switch) and not "waste" it on long mountain climbs?

 

[Rick]

Don't mess with throwing the main circuit breaker unless you just want to tool around and see what it is like without IMA for a brief while. It will kill everything on the high voltage side of things. You'll start the engine using the backup starter motor and won't have the DC/DC to provide 12 volt power so if you get yourself in a situation where the 12 volt dies sufficiently your stuck.

I've done this before just to see what it was like. It will set the check engine light even after you reconnect it. You can make it go away by disconnecting the 12 volt battery for a few minutes, but it likely keeps the code in the computer.

 

[fujii13]

this make me wonder if, for the "mostly highway traveler" if it would be beneficial to remove the battery, IMA motor, and everything associated with it to lighten it up enough to get better gas mileage. thoughts?

 

[Dougie]

Yep. But then it wouldn't qualify for the "hybrid" tax break! :lol:

 

[fujii13]

the government wouldn't know it's no longer a hybrid

 

[originalbadbob]

I would have thought the battery pack would be really heavy, but I read that it is only 49lbs, which isn't going to make much difference.
robert

 

[swhitevt]

I would have thought the battery pack would be really heavy, but I read that it is only 49lbs, which isn't going to make much difference.
robert

Yes, but we're not just talking about the battery--many other components of the IMA system would also become unnecessary. Looking at page 55 of my trusty Insight Encyclopedia, it looks like most of the space behind the drivers seat could be emptied.

Components no longer needed would include the battery, motor control module (MCM), battery condition module (BCM), Battery module cooling fan, Motor Drive module (MDM), Heat Sink, PCU cooling fan, and junction board. The DC-DC converter would have to be modified or replaced as chrs has noted.

I don't know how much all that stuff would weigh, but I bet it would be noticeable.

I don't know how much difference the decrease in weight would make for mileage. I also don't know whether, if the car got "too light", it would get harder to drive (pushed around more by wind, etc). Anyone know?

As far as my experience of mileage with and without a functioning IMA--as I had suspected, it seems that my mpg for high demand (going up mountains on the highway) is a little better with functioning IMA assist. I managed to get 60 mpg on my uphill drive to work, as opposed to my usual (no assist) 55 mpg. Watching the instantaneous mpg I find that with assist going 60 mph I can keep the mpg around 40; without assist, I have to go to 3rd gear and my mpg drops below 25.

My top end (downhill and flat) mpg has not changed much since I got my new battery.

I have to say, the Insight is quite a bit "zippier" with its IMA.

Sara

 

[devin1955]

I have to say, the Insight is quite a bit "zippier" with its IMA.

I noticed that as well. Much more so than I would have imagined considering I read someplace that the electric motor is only 8 horsepower.

 

[originalbadbob]

Yes, but we're not just talking about the battery--many other components of the IMA system would also become unnecessary. Looking at page 55 of my trusty Insight Encyclopedia, it looks like most of the space behind the drivers seat could be emptied.

Ok then 59 lbs, or even 69 lbs. I still don't think it would make enough difference to make it worthwhile. I had thought about that some time ago, but without the IMA, you really struggle sometimes, even though the mileage seems to be best when you use it as little as possible.

It took me several months of trying different things to improve my mileage. I'd make little gains here and there, but one day, it clicked and I picked up about 8-9 mpg and then I went with the OEM tires (my car didn't have them on it when I got it) and picked up about 9-10 more. I drive 50 miles to work each way, 49 of it interstate, but it is pretty hilly, but more uphill on the way home from work and I can pretty much average low 80's on the commute. If the conditions are just right, it's high 80's, but I'm driving 55-60mph. More on the down hill side, and about 54-55 on the uphills.
robert

 

[Foxpaw]

I have to say, the Insight is quite a bit "zippier" with its IMA.

I noticed that as well. Much more so than I would have imagined considering I read someplace that the electric motor is only 8 horsepower.

The reason for this is because the electric motor produces most of that 8 at low RPMs. The Insight's 70-ish horsepower engine is only 70 at it's peak, it's more like 20 at idle - so an additional 8 is almost a 50% increase at low RPMs.