So, I had a battery pack issue issue. It went fine for a bit, but then I noticed that the red battery light came on, but would go out above 1500RPM. So, I swapped in a known good pack. That fixed the red battery light coming on under 1500RPM and the IMA light. One morning, after driving, the red battery light just stayed on regardless of RPM, and the car died after a day. I installed a brand new 12 volt battery, same behavior. I then turned off the pack at the breaker, and am experiencing the same symptoms. Constant red battery light at all RPM ranges. Codes are 1166, 1600, and 1449... I blinked the subcodes out, and I'm getting an overheated pack code. Reset the codes with the new good pack, sets same codes. Even after disengaging the pack via breaker, same codes get set. As a matter of fact, I can reset codes, turn the key on, and after a few seconds everytime, with the pack turned off, I get a hard thud of a solenoid/relay and the IMA light turns on with the check engine light.

Any ideas? Would this point to a DC to DC converter fault? Is there a common fuse/relay failure I should check before replacing the converter? Odd that I'm getting overheating codes set with the pack off, and I still get an immediate IMA light (unless it's because of the fault that's unconditionally illuminating the red battery light).

Thanks everyone in advance for your advice/experience.

 

The codes you are getting are specific to the 2003. Please confirm year.

P1449 is not an overheat code exclusively. What blink code did you get?

While you didn't state that the IMA light was on, IMA light is on for P1600 and P1449. Period.

12V charging is disabled when pack master switch is off. The behavior you describe is normal.

"known good" pack? = HIGHLY doubtful unless it is a new pack from a reputable supplier, or it was transplanted DIRECTLY from an operating vehicle without sitting. You should also be able to confirm the battery is good by reinstalling in the donor vehicle.

I suspect the replacement battery is worse than the original. A battery will deteriorate to the point that 12V charging is disable at all rpm. Your initial scenario is typical for a failed battery that is still "good enough" to allow direct 12V charging from the IMA motor.

Have you been operating the vehicle with the IPU cover off? When the IPU cover is off, all battery and component cooling is disabled.

IMHO, first you need to actually confirm the 10 battery tap voltages are good to two decimal places at the BCM connector (it's in the service manual). They should be almost identical to each other - Certainly less than 0.20V variation, but a truly healthy battery has typically less than 0.10V variation in all 10 voltages. If you don't have this, 100% certain you have a bad battery. Even with nearly identical voltages, it's not a guarantee as they could fall flat on their face under load. You'll need to load test each stick to see how how they respond.

You may have a DC-DC issue, but those fail very rarely where batteries drop like flies.

 

Yes, IMA light is always on now. Known good pack meaning no issues when re-installed in donor vehicle. when I install the old pack in the donor car, it sets more codes (1570...etc) I have used the car briefly without the IPU cover in place testing in 30-40F temps outside. Maybe 20 minutes max driving at a time. I'll verify the blink code, I have it written down in the car.

I cant believe I missed this, but I thought the only IMA fuse contained in a fuse box was under the hood. I'm now seeing that there is a IMA fuse under the column. My stupidity. I'll check that before going any further. Going to feel like an idiot if that was the culprit, but at least I found it...

 

As always sir, thanks for the fast replies...

 

Pretty rare the fuses are an issue. If the "known good" battery is good, it should perform at least as well as the old. I assume the donor car is not an '03?

Limited operation in cool weather with IPU cover off shouldn't be an issue.

Are you sure you didn't have a P1570 in the original car/battery combo?

More items to check:

Ground straps - main negative battery cable and two additional straps from engine and CVT to body ground. They often go bad under the shrink even when visually perfect otherwise. If they haven't been replaced, they probably should.

Try these bypass instructions to see if you can get 12V charging with the master off in proper bypass mode:

http://prolongima.com/hch/removal/bypass.html

Something else you might be dealing with is PTC/no-PTC circuit issue. Your '03 has PTC strips and needs a pack with PTC strips or one that has been spoofed.

If the donor car is '04/'05 the PTC strips were removed at some point. IIRC, there is a code that trips for that, but you haven't reported it.

Note that a simple cheap code reader may not be giving the whole picture; however, the blink codes will get you there.

 

The known good is out of an 04, with a battery serial of 2007, so likely a replacement at some point. The fuse in the interior was bad. Now back to battery light going off over 1500rpm...

When I removed the negative cable, the aux ground broke. Possibly pointing to a fault?

 

Whether they are the primary issue now or not, they will be in the future. Replace all ground straps. Blink both CEL and IMA light codes.