I bought a used 2003 HCH I last weekend. Mistake? Perhaps. But that aside, I would like to see if I can get it running. It was sold to me by a private owner with a "needs a new hybrid battery" scenario so I took the bait investigated the cost of a new battery and decided I'd like to jump in on the Hybrid fun!

I'll try to make this brief and will be happy to fill in any gaps or provide more information where needed.

Car purchased with dead (?) Hybrid battery and confirmed dead 12V battery. I replaced the 12V battery with a brand new one and the car started up and had the red battery icon, CEL, and IMA light. The battery icon remained on the entire time I test drove it around the block, no matter what the RPM. I used a ODBII reader to find codes P1600 and P1593 waiting for me. Tried to reset the codes with said reader and they immediately return. Being stupid and uniformed I then purchased a "reconditioned" battery from a national company that deals strictly with Hybrid batteries. I don't know if I am allowed to name them and would not hesitate to if so because they've been very helpful thus far.

I removed the bad (?) battery myself and took it to them to get it swapped. I then installed the reconditioned Hybrid battery myself, stupidly expecting everything to be peachy! NOPE. Same lights, same error codes, same SOL situation. The *only* difference this time is the red battery light will go out if the RPM's are above 1000 and below ~3500, which I have read is somewhat expected when the Hybrid battery is "bad." The place I purchased the reconditioned Hybrid battery said they've seen this happen a LOT and it's either the ecu for the Hybrid battery or the Inverter. The guy said it's most likely the ecu as they have had to swap them more than the inverter. I then purchased a used ecu and installed it and voila: no change.

At this point I've decided to put the regenerative breaks on and stop throwing money & parts at this problem before it really starts getting expensive. I've read a lot on this and other forums over the past week (this adventure started last Sunday) and I can see that I need help from someone who knows what they are doing. Help!!!!!

Here's what I have tried so far in terms of troubleshooting (feel free to laugh)

1) Yep, I tried the suggestion of driving the car at ~15mph and then shutting it off and then back on after 2 seconds. I tried it before and after replacing the Hybrid battery and the ecu. Didn't do sh*t. Not sure if it has ever been accepted as a real solution, but it did nothing for me.

2) Always disconnected the 12V battery when doing anything (replacing the Hybrid battery, ecu and I guess that's it!) Also turned off the breaker on the Hybrid battery.
3) Removed the number 9 fuse for 60 seconds to reset the ecu.

It is my understanding that P1600 is a generic error code for an IMA issue and P1593 is a voltage error. I own a voltage meter and would be happy to stick it test it wherever I need to to provide readings, but my impression from reading other threads is that people on here seem to already know where to test and I haven't seen any pictures so this could be fun trying to explain it to me (unless there are pictures/diagrams somewhere that I am missing!)

My main concern is that the problem is something that does not involve the Hybrid battery and I just shelled out 1K for no good reason. But if its the Hybrid battery + something else, I'm willing to work on the "something else."

Hopefully I have provided enough info! I'm a quick learner and a "drive it to the junkyard" response will only make me want to fix it more!

Thanks,
William

 

Don't have the manual, but this is what I find:

P1593 Motor current V phase signal circuit – high input Wiring, motor control module (MCM) programming, MCM, motor current V phase sensor

Likely not related to the battery.

Since you've swapped the MCM, it's time to get a manual:

https://www.ebay.com/itm/2003-2004-2...-/361359036229

Run the diagnostics yourself.

 

I don't have my manual with me at the moment, but that is not one of the usual IMA battery failure codes. The variants I have seen are:

P1600(69)
P1637(71) (MCM internal circuit malfunction)
P1569(70) (Battery cell temperature signal circuit problem)

This happens when the software expects one thing about the PTC strips and the battery has the other. (The solution is to cut one wire.)

P1600
P1449

Pack is failing.

P1600
P1449
P1570

Pack is REALLY failing - the voltage taps are way out of spec.

You might also want to get the "blink codes", just in case that shows something your ODB reader doesn't.

 

The manual says that for P1593 check two different voltages and if either is off replace the MCM (motor control module) with a known good one. If that doesn't fix it then it says to replace the motor current V sensor. It is a little hard to tell from the drawing but there appear to be 3 sensors in a block which are placed on each of three power lines to (from?, unclear which direction current is flowing there) to the electric motor. Also unclear if a single sensor can be replaced or all 3 are hooked together. If you open that up and see that they are independent than I suggest (with all power off and the IMA battery switch thrown!) that you rotate the order A->B, B->C, C->A. Then reset with the fuse and turn it on and see what code you get. If it changes to 1591 or 1595 then it was the switch.