I bought 2003 Honda Civic Hybrid, the IMA light and check engine light is on.
I changed 12V battery on June, suddenly the IMA light went out after two days, but check Engine light still on.
However after one week, the IMA light came back, two days later, IMA light went off again. But the IMA light came up again the next day
till now. Last week, my 12V battery was out of battery, I had to charge 12V battery.

The IMA battery fan working well, and IMA battery could be charged to be full, I can see from IMA BAT gauge and IMA asst works also.
I think the IMA battery maybe OK, is it any other reason to cause these issues? How to fix these issues? It doesn't worth to go to dealer,
because this is very old car.

I got five error codes:
P1600
P1491
P1575
P1570
P1449

 

P1600 General IMA fault
P1491 EGR Valve Insufficient Lift Detected - likely a dirty, sticking or inoperative EGR valve.
P1570 Battery Module Individual Voltage Input problem - substantial deviation in the 10 module voltages - 100% guarantee the pack is bad.
P1575 Motor Power Inverter (MPI) Module Voltage Problem - If this occurs with P1570 present, troubleshoot P1570 (bad IMA battery).
P1449 Battery module deterioration - 100% guarantee the pack is bad

You have an issue with your EGR valve and a failed hybrid battery.

 

Can I take the battery out, and charge the each stick cell to be about 14V?
Sorry, I don't know much about battery. Or Do I have to replace the whole battery
which I really don't want to do because it is very expensive. Thank you.

 

No.

 

Thank you, but can I buy single stick and change the bad one if I cannot charge it?

 

The chance of you being be able to salvage anything from that battery is essentially zero. If a single stick measures less than 7.45V, it's bad. If any sticks are less than 0.05V from the highest stick, they are bad.