Hello,

Some history, I replaced the hybrid battery($1500) , new 12V battery, battery contactor/current sensor , DC to DC converter and power inverter. I recently purchased this Honda and it had 8 codes, now with the exception of P1586 and P0AC4 all other codes are gone. After clearing the two codes the car starts up with a small wrench displayed, then IMA light turns on after 30 seconds and car runs at idle or below 2000 rpms with no issues. I have 14VDC to the engine battery and 205VDC to the hybrid battery. As soon as I increase the RPM's above 2000 the main battery relay clicks and stops providing voltage to the 12 volt battery and hybrid battery unit, stops the IMA assist unit from providing power, engine light. and battery light turns on. I can drive the car around if I keep the RPM's below 2000 with the IMA system working providing a charge to both batteries. Cooling fan for the hybrid battery starts up and does it's job as well. Any thoughts on what is happening?

 

I'm not familiar with the specifics of the codes for the HAH. Given the money you've spent, another $42 on a Honda repair manual on CD:

https://www.ebay.com/itm/2005-2007-H...D/132853812495

That will give you detailed diagnostic steps to troubleshoot your issues.

205VDC to the hybrid battery is WAY too high. It should NEVER be that high.

 

I just verified the voltage to the battery and front start up it is 185VDC. To the inverter it is 181VDC. DC to DC converter is providing 14.3 VDC. I know that this is a 144 volt system, so why is the system providing too much voltage? I will check out the repair manual. Thanks for the info.

 

205V is too much. For the other Honda 144V packs, Peak voltage under any condition is 192V.

 

From startup the voltage is 185 and it slowly creeps up to 200VDC+ before the battery relay clicks and turns off the IMA system. I have already replaced the inverter that provides voltage to the battery, so that tells me that the the motor control module(MCM) is not controlling the voltage within perimeters.

I plan to take this car to a hybrid shop on Saturday. This should be interesting. Thanks again.

I will provide an update after it is completely repaired.

 

IMHO, your money would be better spent on the manual and a decent multimeter unless you really trust these guys, and they have proven their competence.

 

I ordered a 05-07 Honda Accord Hybrid manual this morning. I have a really good Fluke meter that is a couple years old, so I should be good to go. I will provide an update when I have more info. Thanks again.

 

I just verified the voltage to the battery and front start up it is 185VDC. To the inverter it is 181VDC. DC to DC converter is providing 14.3 VDC. I know that this is a 144 volt system, so why is the system providing too much voltage? I will check out the repair manual. Thanks for the info.

 

Hello, the issue with this 07 Accord was a failed stator. Had it replaced and have been driving since the original post. Thanks

 

144V is its nominal voltage. If you ever measure the battery at 144V resting, it is completely empty. If the engine was running, you weren't measuring battery voltage, you were measuring the charging voltage from the IMA motor. If you measured 185V at the battery with the engine off, try a different meter.

Thank you for the follow-up.