2006 HCH gen 2 IMA pack

Sure, I’d love to get some feedback on the IMA system
and more specifically the IMA battery issues.

I’ve been working hard trying to understand how to tackle the IMA code with what I have
on hand to work with. Which isn’t much, at least as far as the IMA battery is concerned,
although I’m looking at DIY skills and tools for the job.

In the meanwhile I’ve been monitoring the cars behavior and trying to use the cars systems
to work with the problem instead of against it, while waiting until I can nail down
why the IMA battery pack is throwing the code.

It’s been an interesting two months of ups and downs since my last post about this project. 😉

[quote=”poppajonzz” post=92661]As I said the P0A7F is exactly what you scan tool says, IMA module deterioration. This means that your high voltage IMA battery is deteriorating. The system is constantly monitoring the SOC of the battery, and can tell when the battery is performing out of specification or radically.

If you check for DTCs and P1586 is not also appearing with P0A7F, clear the DTCs. Start the engine. At this point you’re suppose to have a Honda special diagnostic computer to tell you the exact SOC of the vehicle. Since this is not possible for the DIYer all you can do is hold the engine at about 3,500rpm and wait for the SOC gauge to read at about 70%. With an old battery this level might not be possible. Check for DTCs again. If P0A7F is back, and is not accompanied by P1586, you do need a replacement IMA battery. This is an extremely dangerous high voltage battery that you should not attempt to service yourself. Even on a malfunctioning battery the voltage CAN AND WILL HURT OR KILL YOU! At this point a dealership will have to replace the battery for you to achieve proper hybrid assist.

I hope the information I have provided proves to be helpful.[/quote]
Are you saying that if I follow the DIYs instructions and the IMA system indicator and or the P0A7F DTC don’t show up again then it is an intermittent issue?
And also, If I do get the P0A7F code again my only alternative is to bring the car to a Honda Dealer because of the dangerous nature of servicing the IMA systems?

My questions are not in any way directed towards influencing any DIYs to attempt to service any IMA components, but rather to ask you to think about what you are recommending the DIY to do when they are confronted with any of these IMA problems.

I think understanding how any one dealers service dept handles these issues would be helpful.
ie:
Which module is used between the HDS and the vehicle.
Which procedures are followed when using the HDS
What data is collected while using the HDS
And what data, if any was collected, is returned to the DIYs.

thanks for understanding.

[quote=”poppajonzz” post=92822]The Honda dealer would use their Honda specific scan tool to see the SOC. To diagnose this concern they would do the procedure above. There is no real data to be collected, and only the trouble codes are looked at. The IMA system has it’s own self diag that constantly monitors the condition of the IMA system. When it decides the battery is no longer stable it will apply code P0A7F. The only other code that would come up to question the diag of the IMA system would be code P1586 which is, “Battery Current Sensor Signal Malfunction”. If P0A7F keeps coming back without P1586 also being present it means you need a new IMA battery to return to full assist.

“Which module is used between the HDS and the vehicle.”
Honda uses a scantool specially designed for Hondas.

Which procedures are followed when using the HDS; What data is collected while using the HDS
When using the HDS to diagnose a bad IMA battery the main resource is DTCs and SOC. The IMA system has an on-board system that constantly monitors the condition of the IMA system.
What data is collected while using the HDS

And what data, if any was collected, is returned to the DIYs.
Due to the dangerous repair procedures I am not sure what information would be given to the customer other than the DTCs, and a recommendation. It would be a case by case item, and very dependent on the service writer.

Sorry for my harsh views towards self service of the IMA system. While in school they actually show a video of the exact path the electricity will take to your heart, and kill you… They put the fear of god in you! My recommendation when it comes to hybrid systems is calling your local dealership, and seeing if they can cut you a deal on diag time.

Best Wishes[/quote]
just a couple of quick comments and thanks for the explanations.

The reason I don’t like using the quick and dirty remove the negative battery terminal to clear the code is that it clears everything. Same if using a generic scan tool to clear a code. It clears everything.
No SOC no freeze data no body codes no nuttin.

Using the HDS and one of the 4 modules dealers use between the HDS and the vehicle, 2 of those modules are depreciated, the HDS can clear specific codes and leave codes of the other 5 systems
as they are while preserving freeze data.

And SOC is data, but it is never shown to a customer, at least that I’ve ever heard of.
So what are the voltage limits of SOC? The IMA light, P0A7F and P1586 ?
Wouldn’t P1586 indicate something other than Pack Deterioration anyways?

I’ve been to the local dealer, a lot and for a long time, and have seen many changes.
I was not looking forward to having to service this vehicle myself,
but I’m also not interested in a circle jerk with the dealer about out of warranty services,
MVCI or no MVCI. Lots more where that came from so I hope we can move on from here.

Electricians training stresses electrical safety too for obvious reasons.
It’s not a good idea to mess around with stuff one doesn’t understand.