I am the owner of a 2003 Honda Civic hybrid, a manual transmission model. The car has 118K miles on it, all of them by me. The car was purchased in Washington State.
Prologue - A little over a year ago the check engine light came on. I had it checked (don't know the codes) but they said the car needed a new catalytic converter(s) and oxygen sensors for a very large sum of money, saying I would lose fuel efficiency and not pass emissions otherwise. I decided to take my chances and have not lost fuel efficiency and recently passed emissions. The car had the 2007 software update regarding catalytic converter codes but it sounds like there is another from last year regarding O2 sensors I need to have done that may/may not solve this problem. I include this information in the event it is helpful in some way after reading previous threads.
So...yesterday I was driving my car in eastern Washington, reasonably hot day (over 90), going uphill with the AC on which I rarely do when my IMA light came on. I was several miles from a Honda dealership and went in and had the code run (to the tune of $50 and a couple hours). It came back as P1449.
Reading previous threads, it sounds like there can be multiple things going on here. What I was told (although I can't say it was an impressive operation) is that the code was caused by the battery overheating which sounds reasonable based on other threads I've read. I ended my trip early and headed home as I wasn't sure how big of a deal it was or wasn't and didn't want to become stranded.
I've read through a number of threads on the site in the last day (very helpful!) and have several questions I'm hoping someone can assist me with.
The 12v Battery was last changed in February 2008. It was checked more recently and they said that it was fine. However, some of the threads I've read have talked about the importance of having a good battery for the IMA to work properly. So:
1. Could a 12v battery in declining health be a potential cause of the P1449 code? If so, how? It sounds like I should perhaps get it replaced but I don't quite understand the connection.
2. Does changing the 12v battery fix a cause or fix a symptom (that is, take some strain off the IMA battery which is still problematic)?
I have read several posts that have said that an IMA battery in declining health can cause problems anywhere from a little ("I've driven it tens of thousands of miles with no problem with the IMA light on") to a lot ("The 12v battery discharged and the car was inoperable").
3. Given the P1449 code on the IMA, is it more or less likely to be a small problem or a large problem? Is there any way to tell or should I just drive it and find out? I'm trying to figure out essentially how much time I have to drive it and what my risk is of being stranded somewhere as I travel long distances quite frequently to areas far from reliable mechanics.
4. Is there any risk of the battery itself actually overheating and causing damage to the rest of the battery, the car, and its inhabitants?
I have read in other threads that there are options short of replacing the IMA battery from 3rd party solutions (buying a new battery from someone other than a dealer) to home grown ones (recalibrating the battery, turning the IMA battery itself off). I'm wondering if anyone could point me to a good summary of options as I saw a number of different things out there and don't know how effective they each are. And finally...
5. Is there a preferred tool for reading these codes oneself? I've seen them referred to elsewhere but then others have said some of them aren't reliable/don't provide as much information. If this is something that is going to keep recurring, I would ideally like to read and clear the codes myself assuming the device is inexpensive which it sounds like it might be.
I will close by adding that my IMA light went out this afternoon.
Any help anyone could provide is greatly appreciated. Thanks so much!
I should add given what the dealership told me that I am assuming that this was a P1449-72 code although it's possible it was a 73 and they just didn't state it as such, so my questions above are specifically in regards to a P1449-72 or potentially a 73 but not the other P1449 sub-codes.