My 2007 Civic Hybrid had 3000 miles on it when the IMA, Battery and Engine lights came on. I first checked the codes (I bought a scanner and the service manual) and found P0A3F and P15A5 showing. This pertains to the Motor Rotor Current Sensor Malfunction. When I turned off the ignition and turned it back on, the IMA and Battery lights went out but the engine light stayed on. I took it to the dealer and they looked at it. I told them the codes I found and they worked on it for awhile and couldn't reproduce the problem. It was late Saturday and they aren't open on Sunday so I told them I would be back Monday. They said Tuesday because they wanted the same technician to work on it. Okay, that sounded fair to me. Monday I talked with the Service Manager at the dealer to verify the things that I was told. He confirmed everything, so I have no problem with that. The Service Manager said they just don't have many problems with the Hybrids, so the Techs haven't seen many problems.
After taking the car back Tuesday, they couldn't reproduce the problem but they cleared the codes and they called Honda support for help. Honda said they have seen the problem and to replace the Motor Current Sensor. But of course I would have to wait for the part. In the meantime, I did everything I could to make the problem come back. Finally, on the third day of driving around, it happened again and now it seems to be happening more often. So tomorrow it goes into the shop to replace the sensor. The only bad thing I can think of is that they have to remove the transmission to replace the sensor. I'll keep you posted on the situation. I did read in one of the forums that others have had this problem on the 2007 so there may be a common problem developing on the 2007's. Also the Service Manager said it was okay to drive the car without the IMA working (it fail safes itself). But it's not recommended for any length of time.