IMA battery not starting car
 

Honda Civic 2003 with 219,000 miles on it, manual transmission.

I used one of those plug-in-your-car-outlet air compressors, and discovered fairly late that the unit was not registering the air pressure. It filled up the tire far too much, and the unit was very hot. It stopped working thereafter. (I did let some air out.)

Since then, my IMA battery has sometimes started the car, other times not, and it reverts to a wheezy sounding motor start. More and more, the wheezy sounding start has been happening.

I noticed in a recent post that someone turns off their car and back on while driving to get the IMA battery to kick in. That's what I have been doing, and every time when I restart, the IMA battery is turning back on and the IMA battery light goes off. I'm convinced that the IMA battery is not done with its life, but something is keeping it from assisting with the start-up. Any ideas?

Re: IMA battery not starting car
 

Yes. The battery pack is no longer able to perform to spec, and it will only get worse. The only way the air compressor was a factor is if it put a heavy and sustained load that forced the car to charge the 12V with the 144V.

"Wheezy" = cranks like a normal car starter?

Stop what you're doing and go get the codes read. Report back. You are guessing, and nothing you are doing will help your situation.

Re: IMA battery not starting car
 

Thanks for the reply. Yes, wheezy like a normal car, except it hesitates for a moment before trying, then chugs away rather unethusiastically to start the car. It has always started when it does start this way, but every time it leaves me wondering if it will.

Codes are catylitic converter--one that's been around for a long time--and, yes, an IMA battery code. I don't remember which, as it's been several weeks since I had it done, but can go do it again.

The regular battery is also being read as low. I think at 25%, as of several weeks ago. A recent reading last night I had done at an auto store just said "bad." I can't recall ever replacing it since I bought it in 2010 at 73,000 miles, but don't want to sink around $100 into a new regular battery if the IMA battery is truly going bad. Then again, I've wondered if a new battery wouldn't shore up some of the problems.

Re: IMA battery not starting car
 

Replace your 12V battery immediately. A healthy 12V can be critical to proper IMA performance. An ailing 12V will put a continual demand on the dc dc converter, which pulls from the IMA battery or motor. A bad or weak 12V can trigger an IMA light and make a weak IMA battery worse. Replace 12V and reassess.
Consider replacing with a 51R if you have a 151R. Same price and more capacity.

The 12V still runs everything else... coils, fans, etc. It must be healthy, or you will have problems.

When you disconnect 12V the BCM won't know what the IMA SOC is and will read empty. Start and rev to 3500 rpm. Hold until SoC reads full.

Re: IMA battery not starting car
 

There was some problem with the software on the car that caused it to throw catalytic converter errors. If you have never had the software updated that could be what you are seeing. I don't recall the details but if you search for it you should be able to find discussion. Honda got in a bit of trouble over this because they had charged people for a lot of unneeded catalytic converter replacements. That is, the CEL said the cat was bad, but it wasn't.

Re: IMA battery not starting car
 

Thank you all for your feedback.

Yes, I became aware of the catalytic converter issue, and the dealership has reset it, but it comes back. I've just been ignoring it and periodically checking to see if other codes are coming out.

I'll go ahead and get a new 12v battery and see what happens.

Re: IMA battery not starting car
 

I got the 12v battery replaced and was surprised that my troubles went away. The vehicle starts now without trouble and the IMA light has been off now for several days. Well, I guess that was the problem and not the IMA battery (thankfully!). Thanks to those who commented.

Re: IMA battery not starting car
 

You are welcome. Glad to hear that's all it was. Monitor your 12V from now on.

Here in AZ a two year old battery is old and instantly suspect. Heat is VERY hard on lead acid. If I have ANY issues with electron flow of any kind, the first place I look is the 12V battery.

Be watchful of your IMA battery. While a 12V issue can trigger an IMA, it usually doesn't do it with a strong pack. You should watch for recalibrations and investigate grid charging/discharging for maximum battery life.

Steve

Re: IMA battery not starting car
 

Well, there is an outside chance that it was just the 12V, and if so, you were fortunate. However, when an IMA starts to go it can be quite variable. When you replaced the 12V it would have reset the IMA light, and it may just be that not enough time has elapsed before it triggers again. This is a scenario I have experienced first hand when the first IMA battery went. I was really happy for the few days before the IMA came back on, "lucky me, it was just a bad 12V". No such luck.

On a slightly related note, since my 2nd IMA is on its last legs the car now starts about 10% of the time with the starter motor, and there were a couple of instances where it took a couple of cranks, suggesting that the battery was failing. (It was an Interstate, almost 4 years old, and it is hot here too, so that was an old battery.) Replaced it this weekend. The odd thing was that the cheapest source for a compatible 12V was the Honda dealer. Pepboys and Autozone batteries were actually a few bucks more than the OEM battery. First time in my memory that has happened. Since replacing it the car has not started once with the starter. Magic of the new 12V? I don't think so, I think it is just statistics. The IMA light came back on after the battery replacement in about 10 minutes.

Re: IMA battery not starting car
 

I gave it several weeks--still running strong and consistent. So, fingers crossed it'll stay that way. I'll watch for signs and try not to get too disappointed if the IMA light comes on. I'm sitting at 220,000 miles on a 2003 civic. The battery was replaced under warranty at 73,000 in 2009, just before it was sold to me--after years of in-city driving, I do occasional long distance driving of 1 to 12 hours at a time.