My IMA is disabled, computer has a defective IMA battery code. No assist, no regen and the red 12v battery light comes on when RPMs are below 1200 and above 4000 RPM.

Question for those who've had a similar situation. How far/long has your car driven in this state?

First please let me say this has been a simply FABULOUS car. The best I've owned. I hypermiled it the first 4 years of ownership and achieved a 74MPG tank, and I drove 1003 miles on that single tank. I've driven it pretty hard in the last few years, targeting 72-78MPH left lane driving.

Aside from recently, the only big ticket maintenance was a new CVT start clutch at around 110,000 miles.
My CVT had been slipping for quite some time and has needed some neglected maintenance. I was approaching 260,000 miles and the IMA light would come on intermittently but otherwise function normally.

So I took it to Honda a couple weeks back to have all the engine replaceable parts done (Belt, hoses, wires etc), new water pump, new ball joints, CV boots, brakes etc. I also requested a new CVT belt/valve body kit be installed.
Honda called me to say the transmission was too wore out to make the new parts work so I had them install a rebuilt transmission.

My total repair bill was $4400. I really can't complain about the cost because.... heck what do I expect @ 260,000 miles?

So I drive out of the lot with the IMA no longer functioning at all. Dealer says the IMA battery is bad. Although it worked before they repaired everything else.... I guess they're right based on the high mileage.

I am wondering what your opinion is about putting more money into this car in the form of a rebuilt battery? I've had the car since new and still love it a lot. I wish I could have bought a 2nd one back in 2004.

What would you do? Edmunds calculates the trade in value of my car to be $3,674 and dealer retail value to be $6,469. I am not saying those figures are correct but it may provide a reference.

 

Hi,
If you are doing mostly highway miles at 70 mph, I would skip the battery and just keep driving it. Oh, and there is an ebay auction for a battery currently going on.

-Chris

 

Hi Hot Georgia
I have been on this thread periodically for years. My 05 HCH is at 178k, still running well. I wondered why you did not consider a bumblebee battery replacement for 2100, brand new battery. You put the new one in and ship them your old one.
your car might go another 200k.
Pretty cheap compared to new car, especially since you already repaired your hch.
I love my civic, still getting 44 to 46 mpg, hoping to go another 100k but will replace battery with bumblebee replacement if it goes.

 

Update.
My yellow check engine light came on after they replaced the transmission. I also noticed the red battery light comes on if the RPM is below about 1500, and if the RPM exceeds 4000.

The red battery light indicates the 12v battery under the hood is not charging. I suspect there isn't enough generation below about 1500 RPM and it probably goes into an over-charging state above 4000 RPM hence the light operation.

12v accessory power is normally supplied through the IMA. It operates the headlights, radio, wipers, windows etc. When the IMA is switched off in my car, the 12v loads go to the 12v battery under the hood.
That means the lights go dim etc if the RPM's are below about 1500 and above 4000. That has only became a problem while driving in the rain, as headlights + wipers put a heavy load on the 12v battery. The headlights dim and wipers begin to slow down a bit.
But the car returns to its normal RPM range in short order and the 12v battery begins to charge again so it hasn't been too much of a problem.

While at a stop sign or stop light the RPM will naturally drop to idle and that's below 1500RPM so the red battery light will illuminate.
That's not an issue unless it's raining with the wipers on. In that case I'll set the parking brake, put the shift into "N" and rev the engine to about 2000RPM to keep the battery charged.

Good thing 90% of my driving is freeway otherwise that may have been an issue.

Also, the transmission does some rather odd shifting ratio's at times. For example driving down the road I will decrease the gas feed and the transmission will wind the motor up into the 5,000 RPM range. Like driving 50MPH in a normal clutch car and putting it in 3rd gear. It will spin the motor up, hold the high RPM's for a few seconds then drop it back down.
Very strange.
Last summer I had felt it had something to do with Honda's transmission work so I had taken it back for them to look a 2nd time.

The tech said the transmission and installation is fine. The problem is that with the bad battery there isn't enough electrical power in the car to properly operate the transmission.

He said the generator is now putting error codes into the memory so the there isn't any guarantee a new battery will fix the car.

I thought I'd never see the IMA work again, but then it became fall and the weather became cold.

My car "lives" outside and I found when the weather gets around freezing the IMA comes back to life. The IMA light remains on but everything works normally. The red 12v battery warning light does not come on and the rebuilt transmission operates properly.
But it will revert to not working again after driving a few miles.
How far I drive until the IMA stops working seems to be directly related to how cold it is. If it's around 20 degrees then it continues to work for the whole trip.

So it's kind of a odd ride and I will continue to drive it until the next big repair comes along. So far so good. I've put about 15,000 miles with it in this condition.
I reset my trip meters, the last time was about 70,000 miles ago. They said 38MPG. I haven't tracked my MPG in quite some time and I guess it's probably low 30's. Not too bad.

I am hoping I can drive this Honda another year, as I will be able to pay cash for a basic new Corolla at that time.

I'll keep ya'll updated for any changes.

 

So are you still driving with a dead IMA battery? How long has it been? My IMA light came on about 6-8 months ago with the 12V red dash light (in the Chicago winter), so I pulled the IMA fuse to reset it and the IMA hasn't come on since but I feel like it is about to come on any minute. The car is pretty sluggish, though it doesn't bother me that much. I do all urban driving (I have an 8 mile commute each way). I rarely get on a freeway. I am wondering how long I can keep it going this way.

I read your post about when the IMA finally gives out how the 12V battery begins to suffer. I was thinking that maybe something like this would help me get through that in case the charge goes down too low and my car won't start after a day parked in the lot at work?


Curious about your thoughts and experiences!

Steve