Hi,
I own Honda Civic Hybrid 2007.

Maybe my question is very silly but I am out of opinions already. And sadly there is not anyone or any company who would diagnose my problem in my country.

So maybe you could guys. I'll try to describe my problem.

I bought it about 4 month ago. It has 107 000 miles on it. At first everything was fine, but after one week of driving IMA and Check lights came on.
I thought the problem was some battery sticks, but when I checked it they seem okay. Then I changed 12v Battery too. I plugged in OBDII diagnostic computer and it gave me P0A7F Code.

My Honda also have some kind of audio system installed on it, but has no amplifier. I'll show the picture:



I don't know how this hybrid system exactly work and I have doubt that this audio system might be a problem. I know this sounds silly

Another problem that I noticed is that when I start a car and press acceleration pedal slowly it has some kind of hit back. I don't know how to explain that. Maybe this is related to IMA ?
Can anyone give me a qualified answer please? I don't know what to think any more...

It would be great if anyone lists all the possible reasons which causes IMA and Check lights come on.

 

"I thought the problem was some battery sticks, but when I checked it they seem okay" - how? Did you disassemble the pack and individually test all 22 sticks or 11 pairs for capacity, voltage drop and self-discharge?

Your car doesn't have an alternator. It has a DC-DC converter that charges the 12V with the battery/IMA motor. Additional electrical demands directly affect the IMA system.

The audio system has placed a greater strain on the IMA system than would normally be there. Your car is of the age and mileage that battery failure is common.

You say no AMP, but I see devices with "Watts" after them. I'm guessing those are amps.

You likely have a failed IMA battery, and it was marginal when you bought it. The prior owner was likely aware of frequent recalibrations and maybe even an IMA light when you bought it.

IMHO, you need to investigate grid charging/discharging or replace your pack...

Good luck,

Steve

 

Thank you Steve for the reply.

"how? Did you disassemble the pack and individually test all 22 sticks or 11 pairs for capacity, voltage drop and self-discharge?"

I brought my car to technician. (not somewhere official, but to some guy who claims to know hybrids. there is no better choice in my country) he disassemble and checked them individually. hat he told me after was that everything is perfectly fine except of two battery sticks. He told me that this two seemed a little weak but not that weak to cause the IMA light come on. Overall he told me that the lights was not battery's fault. I am not sure if that guy was any expert or just someone who knew a little something.

So, as I see I should buy two new pairs of battery sticks. But what troubles me is that what if it is something else, and my spent money on new sticks is a waste? how can I be sure myself without any support from professional? what would you recommend?

 

I got the P0A7F code along with my IMA light. Code 61-1 also. Something to do with voltage.

 

The mechanic was wrong. Much like "a chain is only as strong as its weakest link," an IMA pack is only as strong as its weakest stick...

He needed to test voltage drop at 100A, capacity at 20A and measure their self-discharge after a week of sitting (or at least a few days). I find it highly unlikely he did a thorough job unless he is in the business of refurbishing/servicing packs. He is likely a "tinkerer".

You can't buy new sticks. They are not procurable. Even if you could, you have no objective data to identify which sticks are underperforming and how they are underperforming. You can find used ones that people have tested and may be good, but again... which ones to replace?

Recommendations (if you were in the U.S.):

0) Disconnect the sound system in any case.

1) Ignore the battery problem. The car will likely be very driveable, but mileage and power will suffer.
1A) You can bypass the IMA battery, and highway mileage will improve, but charging of your 12V will only occur from about 1500 rpm to 3500 rpm, AND you will always have a check engine light on.
2) Buy a grid charger/discharger from Hybrid Automotive, install it yourself. Conduct charges/discharges of your pack and hope for the best. Cost: $450 or so. This can buy you a year or two of fully functional life from an ailing pack.
3) Buy a replacement pack from a salvage yard for $500. You might get lucky and it works. If not, you might be able to use the best sticks from both packs to build a good one and have a few spares left over.
4) Buy a replacement pack with a warranty. In the U.S., you're looking at about $1700 to 2100 with a 3 year warranty.

 

Thank you Steve, you are being much more helpful than any technician in my country

"1) Ignore the battery problem. The car will likely be very driveable, but mileage and power will suffer."
Won't this damage anything else ?

"You can find used ones that people have tested and may be good, but again... which ones to replace?"
Can not I test them somehow just to be sure which ones are faulty and just change them? I guess that is not that easy

I think I will try 2nd option first.


______________________________

Today morning Check and IMA lights went off itself. I did not do anything. I was very happy but it came back on again after about 3 hours

 

1) No. Once the car starts detecting battery issues, it utilizes it less and less, so the battery is not further damaged.

Yes, you can test them, but you'll need to be comfortable with pack removal, disassembly/reassembly and installation (dangerous high voltage stuff). You'll need a couple hundred $$ in equipment, time and dedication. You need to be able to pull a 100A load for 60 seconds and pull 20A for several minute until the stick is depleted. Then you need to be able to recharge them and repeat the capacity test in a week. THEN, you'll need to find suitable replacement sticks... which is tough... again, your best bet is to buy a spare pack and sort out the good ones yourself. In the end, you'll probably be out about $1,000, but you'll be set for the life of the car with your new found DIY maintenance skills.

OR... you do #2 and stretch the life of your existing pack for 1-2 years for about 1/2 the money... and a LOT less time invested in your part.

Steve

 

Btw... What country?

 

Oh, I guess I will have a lot of education to do

thank you again Steve. I think you gave me all the information I need to make a decision.

"Btw... What country?"
Georgia

 

Good luck!