Ok here is the current situation. I hope someone here can shed some light on my symptoms.

here is some relevant info

• i live in tucson arizona
• no covered parking at work
• non tinted windows (for now)
• drive an average of about 450 miles per week

here are some symptoms

• In the middle of the day the IMA system doesnt work
• My AC runs hot when driving in the city
• my battery frequently displays 0 bars for the SoC
• Sometimes it shows a nearly full charge and it will rapidly drop to one or 0 bars
• my Fuel Economy has gone from 45-47 mpg to about 34-35 mpg
• When the IMA system isnt working there is barely enough power to get up an incline that is very very mild. I mean like 1 foot rise over 50 feet.

Here is what happened at the dealer.
I dropped the car off, everyone is super professional and polite. They were super easy to work with throughout the day.
I left to go to work and was told to expect a call later in the day with info.
Well I got a call and they said the Cabin filter is plugged up and that is putting strain on the AC which is then shutting down the IMA. I told them if they though that was the problem to replace the filter and if it fixed it I would pay for the filter. They said they would get back to me
When they got back to me they said they didnt think the filter would solve the IMA issue, but would help the AC. This seems more reasonable. They also said they were pulling out the filter and wanted me to run it without the filter, since i had some in the mail on they way to my house. (they arrived that day and were installed).
There was later another call telling me they dont know whats wrong with my car and dont know how to fix it, but i would have to pick it up and hope that the honda engineers they contacted could come up with a solution and tell the dealer how to impliment it.
My reaction and issues i brought up with the service center were these. and thier answers are after.

1. my fuel economy has dropped almost 25 percent. is honda going to cover the additional fuel costs until they figure out how to repair it.
they said: probably not
2. why did i pay extra for a fuel effecient car if the fuel effeciency would drop below a non hybrid model and honda cant tell me how to correct it.
they said: I understand your concern sir.
2. has my battery been damaged from being totally dead so much.
they said: your battery hasnt been draining, the IMA has been shutting down.
3. What happens long term if weeks go by and honda cant solve the problem?
they said: we will have to talk to honda.


They believe its the heat here in tucson causing the problems. But if honda didnt account for high temps when designing the system I dont really care. no one told me when i got the car that it works everywhere except when its hot outside, then your 25,000 dollar car wont work anymore.

My feelings at this point are that I am going to give the dealer about a week to come up with a solution, in the mean time I am going to follow thier recommendations and get the windows tinted. After a week or so if the IMA is still failing and the dealer and honda say they still dont know why or they blame it on the heat and they cant perminantly correct the issue then I am going to contact a lawyer.

It is inexcusable that the car breaks and they say they dont know why and give my car back.
its also inexcusable that the system would fail under normal high temp summers.

Any advice, ideas or information would be extremely appreciated.

Is it possible that any hacks have been preformed on your system?

Hi tweulfing, I also live in Tucson. Just over a week ago I tinted my HAH windows. I do think that is it very important to keep the car's interior as cool as possible when it is parked outside (this includes using a sun shield for the front window). Not sure if you've been here long but if not, when you first get in your hot car, either roll down a few windows when you start driving (to get rid of that really hot air in the cabin) or at least run your AC on fresh air intake for about 5 minutes then go to recirc.

Also, if your driving is heavy stop and go, in the high heat with the AC struggling, your battery system is going to get run down. And, I think these cars use temp sensors at the IMA battery pack and if it's too hot, it doesn't seem to regen (chrg) OR assist. I have friends here that own a '06 HCH and they typically get 50+ mpg in town. So, I think temp can be a BIG deal (causing high AC demand and keeping your battery pack too toasty) so address that best you can.

I'll be interested to hear if your tint and other things you might do to get your car cooled off helps matters. I think many dealers (mechanics) just aren't that up to speed on the hybrids (yet) - there are frequent posts about hybrid owners being frustrated. Good luck!

Sounds to me like the battery temperature (high ambient temp) is the problem. NiMH batteries should not be charged when the ambient temp is too high. There is a temperature sensor that monitors the temp to help prevent charging when too hot or too cold. I have the same problem here in MA when it's too cold outside. Maybe invest in one of those cheap solar powered fans that clip to a window to help circulate the air a bit. What color is your car? That may also be contributing to the heat build-up. When the IMA doesn't work, your ICE is working overtime and your FE goes down.

I have a similar experience here in Phoenix, although maybe not to the same degree. My commute is about 15 miles each way, with about 100' elevation change over that 15 miles. City stop and go for about half, and fairly open road with few stoplights for the other half, a few miles of highway.

In the morning, I'm going down hill and I don't normally have to run the AZ. I often have trip mileage in the 65MPG range.

After work I'm going uphill and have to run the AC. A couple of times a week I get the battery recal (where SoC drops to zero and forced regen). My mileage drops the whole way home from work, but I still average ~54 MPG.

I'm certainly no expert, but I'll pass on my tips.
- Keep the car as cool as possible while parked. I have tinted glass and a custom fit sun shield for the windshield (Heat Shield - kind of a pain to install and remove, but the most effective I have tried). Windows open an inch. When I get in my car in the afternoon, it's not much hotter than ambient temp.
- Run the AC on auto at the highest practical temp. I set mine on 86. Try it - you'd be surprised how comfortable it is when it's 110 outside.
- Keep your SoC as high as possible for the times you need it for AC. That means accelerating with minimal assist when possible, and taking opportunities for regenerative braking (but only two or three bars - no mechanical braking).
- "Pulse" the AC when the opportunity presents itself, i.e. turn the temp way down if you're coasting downhill, turn it off but select recirc and low fan speed when going uphill. I am actively controlling the AC when I drive. I also turn it off momentarily when I'm climbing an on ramp to the highway.

From what I have read, I think those battery recals and forced regen are just part of life when running the AC in Arizona. I guess I just try to remember that my old car got much worse mileage, even when not running the AC. If your dealer does find some kind of fix, please let us know.

Try leaving your windows open while at work. Have you install a thermometer in your car so you can see how hot it is inside? I would cover my car with a space blanket when left sitting in the sun. I think this would be more effective than tinting your windows and probaly less expensive? It sounds like your pack is to hot. H

I have a shield in the front window and leave the windows open.

the car should be able to operate normally in standard automotive operating temp ranges, a hot day shouldn't shut the system down, not even 115 degrees. This is a huge design flaw.

I am going to ask the dealer to cover some of the window tinting.

I have not "hacked" the car.

Bottom line, if the battery overheats during normal summer days just sitting in a parking lot then this car is defective. No one told me the car would only operate up to 90 degrees F.

this is not acceptable, i shouldn't have to perform workarounds, pulsing AC, leave windows rolled down etc. The car should work without me dealing with this crap.

Why doesnt the AC pipe back to the battery the way the heat does in the winter?

so when they cant fix this what recourse do I have?

115 degree is very extream temp. All cars will be effected by that kind of heat. I still think a reflecting cover is the only answerr? H

115 degrees is only the hottest days. normally 100 - 105 for hot days.

this is not an extreme temp for a car to experience. I saw temps near this back in indiana every summer.

automotive components must survive much higher than 115 degrees.

Twuelfing, I hear you and understand your frustration. Cars in many of the SW citys get really worked over (high temps, extreme UV working on the paint and interior, etc.). Luckily, we only have 3-4 months of that (the brutal heat). I think Honda could widen the temperature parameters so the NiMH battery system would function when hotter (or colder). But the cost of doing that would likely be shorter battery pack life - and this is something buyers have been worried about and have hammered the manufacturers on. Costs on new packs have dropped a lot but I don't know if drivers are ready to sacrifice battery life yet for a better/wider IMA temperature range.

My buddy's wife parks their (dark blue) '06 HCH outside and stills gets pretty good FE. Maybe there is something else going on with your car!?! I hope you can get things resolved. Good luck!!