Hi all,

I have a 2009 Civic hybrid with a few ongoing issues.

When I first got the car, it had a battery degradation code P0A7F, Sent to Honda Dealership and they Flashed the system and the code when away.

a few weeks later the 12V Battery was dead, and the output charge was only 9V... weird, We replaced the 12V and all seemed well.

Later as a precaution re had the hybrid battery replaced with a refurbished unit from a local hybrid battery refurbisher.

in the few months that followed, there has been a bunch of IMA engine lights, battery light, and codes, (loss of communication to Hybrid system, Battery degradation ... so on)

Had the Hybrid battery replaced again (under warranty). Suddenly the charging system would stop working and it started draining batteries. The DC-DC converter was replaced, as well as a Hybrid relay that was found to be bad.

and the car is still dying randomly. Honda is saying it's the Battery Control Module, and that the IMA blower fan has failed as well.

Now I am fully capable of changing out the battery control unit, but does anyone know if it needs to be programmed? I don't plan on buying a new one for nearly $3,000 when a used one is a $100 or less.

Does it sound like this could actually fix the problem ?

 

I saw two question marks:

1) Highly unlikely.
2) No.

Without documenting and reporting the trouble codes for each event, you're basically just asking us to guess.

Given that the 09-11 HCH has the worst hybrid battery in the world (30% failure rate after 3-4 years per consumer reports), and that MOST reconditioned IMA batteries are garbage, AND that the original issue was a P0A7F, I'm guessing you have yet to install an operable IMA battery.

Yes, a failing hybrid battery can disrupt/eliminate 12V charging and/or make it intermittent.

 

Here is the current list of Codes
Permanent
U1205 - Lost comm with MCM
U1206 - EPP(IMA) - Can Malfunction
U1207 - EPP(IMA) - Can Malfunction
U0110 - Lost comm with IMA MCM
Temp
U1205 - Lost comm with MCM
U0110 - Lost comm with IMA MCM

CVT Perm
U0037 IMA CAN Malfunction
U1205 - Lost comm with MCM
CVT Temp
U1205 - Lost comm with MCM

ABS
61-22 Modulator Control Unit Power source Low

EPS Perm DTC
21-02 Comparison vehicle speed an engine speed Signal
12-01 Motor Control Unit Power Supply Voltage
12-01 Motor Power Supply Voltage.

The second Hybrid Battery that was installed came from the owners of the refurbishing shops personal vehicle, I seen him pull it out and install in in my car,

Anyone have any idea what could be the issue ?

 

Is the 12V FULLY charged when those codes are read (> 12.5V resting, > 11.6V ignition on/engine off)?

 

The 12v battery has been replaced 3 times, the last was a few weeks ago when Honda replaced a relay that was causing a Parasitic loss.

However, before that when I was trying to figure out why the car died, I checked the charging system and it was only putting out 9v, (IMA light and Battery light was on) as soon as I connected our booster pack to the battery the charging system went back up to 14v, and the IMA and battery light disappeared. (only to return the next time the car was started)

 

While a lengthy and content-packed reply, you didn't answer the very simple "yes" or "no" question. I asked you a VERY specific question for a reason.

The reason is that if your 12V battery is low or weak, the codes read can't be trusted. THAT MANY codes SCREAMS your 12V was low at the time the codes were read, which means the codes may or may not be valid. Given that two codes from two different sources report low power SCREAMS a low 12V battery is triggering those codes. If your goal is to find out WHY the 12V battery isn't charging, you have to start with a fully charged 12V battery.

Disconnect the 12V
Charge it until it is full.
Reconnect 12V
Drive the car for 5 miles with minimal accessory use.
Check 12V charging.
Check and report codes.

Something like this would be VERY useful for you:


You will be able to directly read the system voltage when ignition on/engine off as well as when running. You should be able to see a correlation between when the battery light comes on and the voltage drops. If the 12V light is off, you should see voltage north of 12V while running. If the 12V light is on, you should see voltage dropping.

To state it one more way...

You can't reliability diagnose a fault when the 12V battery is weak or discharged.

 

I'm getting the car back from the dealer later this week, will test and advise.

I have a fresh battery that is fully charged I can swap in once I get it back and let you know.