Hey everyone,

The short story of my problem is that I replaced the battery in my 2003 Honda Civic with a refurbished one I bought online. After testing the 12v, we found that had been drained (we think by the failing IMA), and replaced that too. Now the car will start, but the hybrid battery is still not charging, the IMA light is always on, and the 12v battery light goes on and off while driving (we've only taken it a few blocks to test it).

So now I'm guessing one of two things:

1. There's something wrong with another part of the whole IMA system that's preventing the battery from charging, and I just spend roughly $3000 for a battery that didn't need to be replaced in the first place.

2. We need to have the car's computer updated to recognize the new battery. After that, it'll start charging when I brake, like it should. A friend of a friend works for a Honda dealership. We gave him the serial numbers from the batteries and the VIN, and he said that because it matched, we might not have to have the computer updated. But reading around online, it sounds like it might be a good idea to have it looked at anyway.

Anyone have any ideas or insight?


If you want the longer version of what happened...

I bought my car used in 2010 with 65,000 miles. Didn't have a problem at all until December last year. The IMA light came on, but it was still charging normally and I was getting the same gas mileage. We took it to the Honda dealership because I needed some updates and recalls fixed anyway and then asked them to look at what was causing the light to come on. They told me the battery absolutely had to be replaced, which would cost me $5000. I told them I would take it home and think about it, because I certainly don't have that money.

When we got back in the car to drive home from the dealership, the IMA was completely drained, wouldn't charge, and the regular battery light was also suddenly on. I was upset, because it was basically working perfectly until I had them look at it. Two days later, the car wouldn't start. Had it towed back to the dealership to point out that it had been working until they touched it, they still told me the battery had to be replaced. Towed it back to my place.

I ordered a battery from Green Volt Hybrid Solutions, costing roughly $2300. I installed it at home (yes, yes, high voltage, etc.). The car still wouldn't start (no lights or anything) and when we tested the 12v it only had about 8v, so we replaced that. Now it'll start, but the IMA isn't charging and the light's still on.

Help?

 

Read the code and report it here. Then we can help with troubleshooting.

It seems like the DC-DC converter does not supply current to 12V line.

 

OK, I've got the codes. P1600 - which I believe means a general indication that there's a problem with the IMA. Then there's also P1569 and P1637, and I'm having a really hard time figuring out what those ones means - I can't find a list online anywhere that includes either of those two.

 

P1569= Battery Cell Temperature Signal Circuit Problem
P1637= Motor Control Module (MCM) Internal Circuit Malfunction

This comes from the '03-04 service manual. For both codes the first thing it says to do is reset the MCM. One way to do that, according to the manual is to:
Turn the ignition switch off, then
Remove the #9 backup (10A) fuse from the under-hood fuse/relay box for 60 seconds. (It notes that when you do this the IMA will read 0 bars.)

[Sometimes the dealership's parts department will let you take a look at the service manual if you don't have one. You can purchase one from helm inc.]

 

OK, we ended up taking the car to a Honda dealership, where they installed 3 updates in the car's computer. All fixed! So excited to have my car back.

And a side note - the people at Green Volt Hybrid Solutions are really wonderful. We called them several times for help on installation, and they're the ones that told us we probably needed a computer update. I've very happy with their customer service. Now to wait and see if the battery holds up.