So a few months ago Honda told me I needed a new battery for my 2004 Civic Hybrid. Well I bought one recently and put it in but now the battery charge level is at 0 and it won't show a charge/assist when I drive it. The IMA light and CEL is still on of course. I got the codes that are currently on it which are P1600 (generic IMA) and P1569 and P1637. I took it to Honda (who of course charged me even though I told them the codes) and they are saying now that the MCM is broken. I'm not sure if this is right or if they are trying to swindle a poor college student. I'd really appreciate any advice.

Thanks

 

P1569 Battery Cell Temp Signal Circuit problem.
Did you plug all the connectors back in?

P1637 MCM Internal circuit malfunction.
Unusual and unlikely IMO need to carefully check the battery installation.

Was it a new battery?
Who did you get it from?
Did you move the switch board from one battery to the other?

 

Yes I made sure all the connectors were plugged back into the same plugs I removed them from. I am not sure about the switch board you are speaking of though. Could you elaborate where that would be located at?

 

Switch board is on the end of the battery. All the connectors and devices on it.

 

soooo... I have made sure all the connectors and devices were transferred over now. It still has an IMA light and CEL but it has a new code instead of the others now, it is a 1575 according to advance auto. Any ideas what this may be?

 

1575 motor power inverter voltage problem.

Take off the ipu cover, switch the battery back on and carefully measure the voltage at the battery terminals (two thick orange wires on top) with a 600V DC meter when the car is started, rev it a bit what does it go up to?

If it goes above about 190V then the main 100A battery fuse is possibly blown.

 

What does this 100 amp fuse do exactly? The car still has charging/assit working and it seems to be recharging the battery as well. I'm used to if a fuse blows then whatever the fuse goes to stops working.