Hi, I have an 05 HCH, manual with just over 200K on it. I have replaced 3 12 volt batteries in 9mo. The IMA, brake, and ABS lights would come on, then within a week or so, the batteries would die. I was told by a dealer thet my IMA needed replacing. I had to take it to a second dealer to have the work done as 1st dealer was/is in bankruptcy. 2nd dealer replaced IMA battery assembly. Told me that the code showed that the ABS module needed replacing, but that could wait. Picked the car up - they had left a door not shut and drained the new 12volt. Jumped the car, assured me it would be fine. Assured me that the ABS problem was not critical, and I could take my time replacing the module. All of the above lights were still on, next day the car was dead. My husband charged it twice over the weekend and it wouldn't hold the charge overnight. Got them to replace the 12volt battery on Monday. We had to disconnect the 12 volt whenever we turned off the car or it would drain. My regular mechanic (non-dealer) replaced the ABS module today. Lights were all off, until after I stopped for gas. Now they are on again, the ABS code has cropped back up, and I'm sure I'll have a dead battery in the morning. I am desperate for any suggestions. Until now I've been happy with my car - not so much with the dealers.

 

Since this is the 2nd dealer and I assume this was a very expensive repair I'd get the Honda regional service manager (Not just the dealership service manager) involved.

I'd request a meeting with this regional Honda service manager. They have more authority regarding Honda Corp and can authorize more things than the dealer's manager can.

 

I have a 2004 HCH with 114,000 miles and just experienced a similar situation. I recently was left stranded with a 12v Dead battery and had to get a new 12v battery. A few weeks after getting the new battery My ima and check engine light went on and i took it in to the dealer. the dealer did a software update under warranty. then two weeks later ima and check engine light went on and dealer told me I need to buy $3000+ ima battery. Battery not under warranty. thanks but no thanks. Whats weird is the ima system was working normal. Just the annoying ima warning lights on. Then a week later the abs light goes on. Next day dead 12v battery and car won't start. Taking things in my own hands and after contacting a Honda mechanic friend I was told to buy a new 12v battery and reset the MCM which is a realtively easy task of pulling the correct fuse under the hood and charging the IMA battery back to full by reving the car while in Park or Neutral. And then letting the Car realearn while idling for about 10 minutes.

My problem was solved in a matter of 15 min and cost of new 12v battery.
So far my HCH is running good and all my warning lights are gone.

I am getting anywhere from 37 to 45mpg right now. varies.

Crossing my fingers that the MCM reset holds.

UPDATE FYI - MCM reset DID NOT HOLD after just over one week. Check engine light and IMA light came back on.

suspect the bad AC compressor relay issue that other HCH owners are experiencing with slow electrical leech of energy to 12V system.

Understand that the HCH is very sensitive to 12V issues.

 

Could you please post the extra process used to reset the MCM by pulling the IMA fuse under the hood? Is the 12V connected/disconnected while the fuze is pulled? Car running or is the switch off? etc. The exact conditions would be appreciated so I know I have executed everything that is needed to reset the MCM.

I have a 03 with charging problems (see my other desperate posts) and I believe the problem of running down the 12V overnight is happening (bought a new 12V and it seems to take a significant charge time from my 6 amp charger to reach full charge after sitting overnight).

I am looking for some way to get the IMA charging to restart (IMA battery shows no charge and the charging indicator only intermittently showings a few bars of charging upon startup (using the 12V starter) before disappearing. I did have one occurrance of a more prolonged charge enough to get two bars of charge on the IMA battery, but that did not last or occur again on several restarts.

I have pulled the underhood IMA fuse to check it in the past and also the IMA fuse (controls the light on the dash) in the box under the dash. But that was early before I bought a new 12V battery to replace the bad one that was in the car.

I am somewhat convinced the MCM has somehow gotten in a state of shutdown after the car sat for a while (months) before I bought it. This is also somewhat based on the fact of getting the one time occurrance of charging and achieving 2 bars of charge (but I'm also grasping at straws at this point. Perhaps problems all due to sitting or the IMA battery has gone bad? I am trying to avoid the expense of taking it to the Honda dealer and any help you could provide would be appreciated. Codes I have pulled are 1600 and 1575, but not the bad IMA battery codes in the 1400's. 12V battery light also comes on when the idle is 1200 rpms or below. I don't have an ABS light on.

 

Hi John,

Sure.

I can't guarantee anything as I am NOT a Honda tech or expert...and I am still crossing my fingers that this MCM reset thing fixes my problem and that I don't have the AC Compressor Clutch relay short like many other HCH owners.

Anyways - the MCM reset. How I did it.

The order which I did the reset (not sure about official way to do this)...but here is exactly what I did.

1. I disconnected and removed the Old 12V Battery
2. I then installed and reconnected the brand new 12V battery...negative first and then positive terminal. In my case I bought a Costco brand Battery. If it matters...just to be specific.
3. I then pulled the #9 10amp fuse out of the fuse box right above the 12V battery. The #9 fuse is the bottom right fuse in the middle of the box. You will see a 3x3 array of these fuses. again bottom row far right.
4. Wait at least 60 seconds and then reinstall. This is supposedly the MCM fuse and it will deplete the charge of the IMA indicator down to zero.
5. Insert key into ignition and start vehicle. (in my case it started without issue)
6. Make sure vehicle is in Park (I have an automatic) and rev engine at 4,000rpm continuously until the IMA charge indicator reads full. It took awhile before I started to see a charge...be patient...process took me approx 5 minutes of holding the gas pedal. very noisy too.
7. Then I let the engine idle for at least 10 minutes. supposedly the car needs to relearn during this time period of idling.
8. I forgot whether I turned off the car and then restarted it or just drove off immediately to test the car.

But my IMA warning light, check engine light, and ABS brakes warning light dissapeared and am happy so far.

Only time will tell. I am almost one week in so far. Crossing my fingers as it took two and a half weeks from my previous Honda Dealership IMA software update before my HCH died last time.

Good Luck. I hope this helps

 

Thanks for the reply and detailed instructions. I gave it a try, but no luck. Some things are slightly different for me. Mine is an 03 MT. When I looked in the owner's manual the number 2 fuse in the 3/3 array, top row, middle slot is labeled IMA and the number 9, bottom row, far right is labeled backup. It gets even more confusing in that pulling the number 9 or number 2 or both don't shut the backup lights off, in fact none of the fuses in the 3x3 array shut off the backup lights (I assume backup as labeled in the manual means backup lights). I pulled all the fuses in the 3x3 array one at a time and all the rest seem to control what they are labeled (stop lts, parking (labeled "small" in manual), horn, etc. So...I'm stumped. Did the run up to high rpms anyway. When I got close to 4000 the 12V battery light came on (I think that is suppose to happen). Ran the car at 3600 rpms for a while with no indication of charging or any sign of charge in the IMS battery.

You mentioned the AC compressor clutch relay relay short problem. I do have an intermittent AC, ...wasn't working, then worked (great in fact) and now is not working again. I had read the post on the shorted AC relay running down the 12V and so I had switched some of the relays in the fuze box around (all labeled the same). I have done so many "experiments" now that I can't recall whether that fixed the AC before, but I don't think so. Does anyone (besides someone at Honda) know whether the hybrid controls the AC working or not depending on conditions in order to "save gas"? When I had the AC working before it seemed to work fine (only AC button light, not recirc or econ) on the road and at idle. If I am having MCM problems it may be shutting the AC down. Both coolant fans do come on. The passenger side one seems to come on when the AC is turned on.

I think my next experiment is going to be to pull every 12V relay I can find (already have seen several in fuze box, behind glove box (3 there and one clicks when starting car) and I heard one behind the back seat when I attempt to start the car) and use a 12V connect off the car to try and test if the relays pull in or not when 12V is applied.

Again I appreciate the reply. Any other ideas out there? Not ready to go back and pay Honda yet, but getting close.

 

John,

Sorry it did not work for you....

however my 2004 HCH fusebox is same as yours. #9 is the backup.

unsure what that means...backup light/ backup memory? not sure...I was just told to pull that fuse.

I assume that you rev while in neutral since you are MT and if your battery light is coming on...well I would imagine you have worse electrical issues than my situation.

BTW - bad news....deja vu all over again....

the MCM reset did NOT hold after all...

IMA and check engine lights came on again this morning while driving...just over one week later after replacing new 12v battery and doing the MCM reset.

My gut feeling is that I have the AC Compressor Relay short issue as documented by other folks....

The short in the relay causes a leech on the electrical system without the key in ingnition...kind of like leaving radio on all night long.

I am going to try one more crazy idea for myself before I try to fix the very expensive relay.

I just bought a Solar Cell Car Charger. I am hoping that the charger will keep the 12V battery topped off during the day while the car is sitting in the parking lot at work or at least closer to the top to try to fight against the negative leech. going to have to hardwire this one in... since accessory socket is only on with key in ignition.

wish me luck and good luck with trying to solve your own issues - sorry to hear that your situation is worse than mine.

Thanks.

UPDATE: Just called dealership and supposedly the Relay is only $8. Going to go buy one and replace it today.

 

Thanks for the confirmation on the number 9 fuse. If you ever want (for whatever reason) to get rid of the "annoying" IMA light on the dash just remove the 7.5 amp in the underdash box! Not sure what the 10 amp number 2 fuze labeled IMA on the underhood matrix is for. I thought it was interesting that the backup lights are not controlled by any of the fuzes (40 amps or less) in the underhood box. You would think there would be a readily accessable fuse for the backup lights. I think I need a service manual just to satisfy my curiousity.

Glad to hear the relays are only $8. You had me worried again the another item on the hybrid was going to be outlandishly expensive. Now if I fry one testing it, I won't feel too bad! If $8 is the dealer price, they can probably be bought for $4 online somewhere.

My problem with the 12V light coming on below 1200 or 1400 rpms seems like a generator (the IMA motor in generator mode) not spinning fast enough to generate more "current" than is being used. My understanding of the diff between a generator and an alternator is that the alternator puts out the same amount regardless of how fast it is spinning whereas a generator is proportional to the speed it is turning. The IMA motor works as a generator is my understanding. I read that the 12V light coming on (not generating) above 4000 rpms is normal (probably a way to reduce the load on the engine is this extreme case so all the power is available. Just guessing how the Honda designed the control system.

I have been trying to figure out how to set the idle rpms up above the point the 12V comes on. Only adjustment that is readily accessable is the throttle linkage which has a double nut system that might allow adjusting so the cable keeps the throttle more open at idle (puts stress on the throttle wire so I am thinking this is not the right place to adjust, but any other adjustment (manual) must be buried down under all the "stuff" were the linkage disappears. Usually there is an manual adjustment on most cars that moves a mechanical stop/tab to set the idle speed. Anyone have any info on how to set idle speed on this car?

Good luck with you problems. It seems there are lots of ways (and symptoms) that these Honda Civic Hybrids car fail, perhaps all tied back to the $3000 IMA battery getting old and unbalanced (and no easy way to just charge them up external to the car system even if you have to do it every night). Other posts talked about doing over night "grid" charging on Insights to delay the onset of out of balance (viewed as bad battery by the car monitoring system) IMA batteries. Oh well, interesting stuff (maybe for a while, but then it is going to get old).

 

John,

quick update. Bought the new AC Compressor Clutch Relay today. It is $30. Not the $8 quoted over the phone....go figure...but $30 still better than $3,000 for a new IMA battery. and not the $1500 that other people are talking about on other blogs in regards to fixing the compressor cluth...maybe they replaced their whole AC compressor assembly...?

Anyways - disconnected 12v battery, swapped out relays, did the MCM reset process again and all is clear as far as warning lights.

Lets see if this solve holds for another week.

On a side note: a friend at work who also has a 2003 HCH mentioned they had a friend that also has a HCH mentioned that the warranty on the HCH IMA battery is supposed to be up to 150,000 miles as they got theirs replaced under warranty. Which is weird because the local Honda dealer said mine is not under warranty....go figure. have you heard anything on the warranty limit of the IMA battery?

Thanks. Good Luck with everything.

 

I couldn't find the link for the 2003 HCH, but I think the warranty was the same as for the 2004. It depends what state you live in, and if your car is a ULEV or SULEV emissions model:

http://www.honda.com/newsandviews/ar...=2003100849312