IMA not charging or assisting
 

So I have a 2003, 5spd and a while back my IMA light came on along with the CEL. After some testing I found the problem to be what I believed was the IMA battery. Tried refurbishing the sticks individually, but still had the lights. Charge/Assist were still working fairly normal and battery would show a full charge, I just couldn’t get the lights to stay off for long. I figured the “refurbish” didn’t go well and just bought another used one out of a 2005 automatic. This battery was from a running vehicle with no CEL or IMA lights on. Put it in mine and CEL, IMA and 12v light are all on. 12v light goes off between around 1,500-3000rmp, so I know the dc-dc is good. I hooked a voltage meter up to the main hybrid batt and turned the key to on, which registered 155v, then I hear a click and it drops to zero. If I start the car I get a fairly low voltage reading and if I quickly turn the car off and back on it will stay higher and increase to 180plus the higher the rpm. Nothing registers for charge on the dash and no assist at all. No clue what’s wrong or what to check at this point. Any help would be greatly appreciated.

Re: IMA not charging or assisting
 

This is one of those very common issues where the tool behind the wheel is actually a monkey wrench, and it just keeps getting thrown into the works mucking things up. The car is SCREAMING that something is wrong (lights). All you have to do is gently insert something appropriate into its port and LISTEN...

DUDE! READ THE CODES!

Pray for a P1569.

Re: IMA not charging or assisting
 

This is actually a project I just picked back up after two years of the car sitting. I originally did read the codes and know one of them was P1600. There was one other, but I’ll have to find where I placed my note. Not that it’s necessarily relevant, as the problem now was not happening then (everything worked fairly normal, but had IMA, plus codes). The recent battery was just put in a week ago. Unfortunately I don’t have a scan tool to check it and it’s not on the road currently. I’ll try to pick one up and see what they are.

Re: IMA not charging or assisting
 

P1600 means "you have an IMA problem". It's basically what turns the IMA light on. It has no diagnostic value. The "other" code is the one that mattered for the old battery, but an '05 battery in an '03 likely has new codes because they typically won't work without modifications.

Key off, insert paperclip to short the two pins shown (don't short the wrong pins), key on (NO start), count the IMA light blinks and the check engine light blinks (I recommend you video it until the pattern repeats a couple times):

http://99mpg.com/categories/insight/readingtheblinkcod/

The pages are for the insight, not the HCH, so let me know what the blinks are.

Re: IMA not charging or assisting
 

Blink codes appear as follows.

CEL: 69
IMA: 12 & 73

Re: IMA not charging or assisting
 

69 = P1600 IMA Fault (thrown by ECM to direct you to the IMA system troubleshooting and illuminate the IMA light)
12 = P1575 Motor Power Inverter (MPI) Module Voltage Problem
73 = P1449 Battery Cell Overheating

P1600 can be ignored
P1449(73) - sole resolution is "replace battery module"
P1575(12) - this may be associated with low 12V due to inconsistent charging or loose main battery cables. P1449(73) should be resolved first to see if P1575 remains.

My first recommendation is to see if you can get the MCM from the same car you got the battery.

My second recommendation is to spoof the PTC circuit with a 20-30Ω resistor (1/4W or better). if you recall from your battery rebuild efforts, there was a single thick red sheathed wire on the junction board end plate that connected the two ends of the PTC strips. It's almost certain the 2005 battery does not possess the PTC circuit as it was eliminated sometime in mid 2004. Your "old" MCM expects to see the PTC circuit there, but it sees infinite resistance, so it registers that your battery is hotter than the sun. The "new" MCM expects an open circuit where the PTC should be, hence my recommendation to obtain the "new" MCM from the car from which you obtained the battery.

Third recommendation is to have the dealer update the MCM (probably cost you > $150).

I'm not confident any of the above three will fully resolve the problem until we get to the bottom of the P1449(73)

The MCM is the box in which you plug the orange battery connector (14 pin).

Re: IMA not charging or assisting
 

I’ll try to get the MCM and see what effect that has and report back as soon as I know. Thank you for your help.

Re: IMA not charging or assisting
 

You're welcome. Thank you for blinking the codes. We know vastly more than we did before.

Re: IMA not charging or assisting
 

I am having a similar issue.
New battery pack.
No lights after reset, drive it and I hear a click then all bad lights. IMA, cel, red battery.
The battery charge light disappears, the charging and assist lights go blank too.
P1600 and p1586

Reset and it goes away until click and same thing.

​​​​​​​Any resolution?

Re: IMA not charging or assisting
 

Do I have to answer you here too?

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