I have 2003 HCH Automatic 108K miles. Few weeks before, IMA was almost like 60-70% showing. But when I started the car the morning, IMA indication went to Zero and IMA, CEL came on. I needed to drive to office, so i drove like 5 miles to office and the same evening when i returned, i saw the Red battery indication showed up. I drove home and parked it. Now when i start, i see IMA,CEL and Red Battery Light on. I ordered a Code Reader to check and it showed these below codes in Torque app.

P1600, P1575, P1570 - Red ( Current Fault)
P1601, P1435

I almost had same issue like 6 months before and that time serviced with dealer and they said to replace MCM module. Dealer was quoting 2000$ for MCM alone. So i bought one in ebay and requested them to replace it and it worked fine for 6 months. Back again the issue.

Any suggestions how to proceed to have it fixed?

 

Have you ever had the 12V battery replaced? Just asking if the Red Battery Light means a bad 12V battery.

 

12V battery is almost new one and replaced at Honda Dealer less than a year now.

Googling Internet i found this info
From Insightcentral encyclopedia

"The MCM may stop DC-DC converter operation if certain IMA malfunctions occur, or if the DC-DC converter's temperature rises abnormally. Any time that the DC-DC converter is not functioning normally, the charge indicator lamp on the instrument panel will be illuminated."

Also i tried to bypass computer using this procedure
http://hybrid-battery.com/hch/removal/bypass.html

I did see when idling above 1500 rpm the red light goes off and comes back when rpm reduces less than 1500rpm.

I want to test using a known good MCM.
Could someone suggest a good place to buy the MCM module.
Last time i tried ebay and it lasted like 6 months. This time i want to try some reliable source.

 

Maybe try:

http://car-part.com/

or Majestic auto parts

or Bernardi auto parts.

 

After Bypass, my car seems to run fine and charges battery when RPM above 1500.
So does this indicate MCM is good?

I believe when RPM is less than 1500, Hybrid Battery/regenerate will provide power to MCM which in turn would charge 12V. I may not be correct just asking.

Also could any one suggest if we can replace MCM ourself like Hybrid battery?
or only have to go thru dealer?

 

I know this post is old... but did you ever resolve this issue?

 

Nope..
This mostly seemed like Voltage imbalance on hybrid battery sticks.
Dealers near me doesn't seem to have great knowledge on these hybrids and as per their testing procedure, they wanted to replace with a known good MCM. But they said, I have to buy a new one. since they don't have to test.
I don't wanted to spend much, so I just bypassed so switched off IMA and ran like gasoline car, still I got good mileage around 38city and 40 in highway.
Only thing was not to leave car in idle below 1500rpm..

I drove more than a year with bypass and traded vehicle for Accord...
It was really a great car for me for 7 years i had and saved much on gas.