marathoner65

Hi All--

I have a 2003 HCH CVT 126K miles. IMA module replaced under warranty at 78K mi. Been having IMA CEL occurrences the past several months. Had the codes read a few months back (P1435/1570/P1449)

Service report says:
"DTC's Stored Battery Deterioration"
"Estimate to replace IMA and swap junction board -- $3400"

I did some reading (seemingly 100s of documented cases out there) and learned that possibly all is not lost with these codes and it is possible to try some other fixes prior to replacing the IMA battery pack (again) at great expense.

I found my 12v battery was low and replaced it (under warranty).

I followed instructions from a few HCH posts suggesting resetting of IMA system via IMA fuse pulling under hood and under dash and replacing.

I even tried one suggested service tech's IMA reset procedure of turning car off while rolling at

marathoner65

rest of post---

. . . at less than 20mph then turning the car back on---resetting the IMA system.

Doing all of these steps results in IMA/CEL light going out and staying out for ave 3-4 weeks.

What I'm experiencing with the car is this:

(1) IMA battery charge indicator level varies widely during even short trips. Level will start at 3 bars, then jump to full bars in 1-2 mins, then drop back to 3-4 bars just a few mins later, all on level ground.

(2) IMA charge (green bars) indicator seems the often be in constant charge mode when cruising (10% accelerator). When 50% accelerator level, charge stops and IMA assist kicks in.

(3) IMA regenerative braking recharge seems normal when going downhill and braking

I'm wondering that seeing I had the IMA battery pack replaced at just 50K mi ago, and the power seems fine, but the battery level indicator seems erratic---that it could be a faulty IMA control module component of the IMA system?

I've seen this quote as a $1000+ repair in places, but I've also seen this part listed at $200-$500. Is this a reasonable step to replace this part prior to considering a full battery pack replacement?

NOTE: While I do some minor work on my HCH (brakes, CVT fluid, oil, plugs, etc) I have no interest in doing any work on the IMA system. I'm not a trained HCH mechanic and the high voltage aspect of that system does not appeal to me. I'm only interested in feedback so that I can have an informed convo with my service rep at my dealer.

Any thoughts/advice/clarifying questions are most appreciated.

ezone

Needs another IMA battery, as per the fault codes you posted.
Prices may vary greatly, even among dealerships.

50k and how many years ago was the battery replaced?
Call Honda customer service?

Does the car sit a lot? It's kinda easy to ruin the IMA battery if it sits a lot without someone running the car to recharge that unit once in a while.

marathoner65

----It is driven usually every day, but short (10 mi round trip) commute is the norm. I've read that might be an issue. Not enough miles to keep battery healthy.

ezone

If your driving habits are still the same as during the first half of the cars life....that doesn't seem all that much shorter than the lifespan of the first battery.

Maybe yeah kinda....but
Have you had the car at a Honda dealership to be checked out for this issue yet? (official diagnosis)

Do you frequent the dealer for your regular services?
I don't necessarily think that's too little (JMO).
I meant not driving the car for weeks or months at a time is what can hurt the battery.

marathoner65

----Thanks for the perspective!

ezone

I asked about your service work because customer service may consider your service history with their dealers if you call them about your IMA battery issue.